tag:blogger.com,1999:blog-82602793856149948722024-03-05T05:29:26.301-08:00Blue JotterPhibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.comBlogger33125tag:blogger.com,1999:blog-8260279385614994872.post-41930408421323823252012-10-24T02:18:00.001-07:002012-10-24T02:18:22.052-07:00Installing DELL laptop drivers from CABsRecently, I had to rebuild my Dell laptop. Not fun. Hoping to save someone else a little time, here is how I got all the drivers sorted:<br />
<br />
<br />
<ol>
<li><b>Find <i>your</i> driver bundle</b>: I used the model code (printed in a shallow recess on the underside) to find a CAB on the Dell website containing all the drivers for that machine. Big download - almost a gigabyte - but so handy to have them all in one file! </li>
<li><b>Extracting the drivers from the CAB:</b> Windows Explorer can natively poke around inside the CAB, but extracting is a pain - one file at a time, losing the directory structure - really, a non-starter. Don't do it. Instead, just <a href="http://www.7-zip.org/">download and install 7-Zip</a> (free!), which will do the job very nicely. After that, </li>
<li><b>Use the Device Manager to install the drivers:</b> Hit Windows+R to launch the run dialog, then type (or paste) <b style="background-color: white; color: #333333; font-family: Verdana; font-size: 12px; line-height: 18px;">devmgmt.msc </b><span style="background-color: white;">into the text field</span><b style="background-color: white; color: #333333; font-family: Verdana; font-size: 12px; line-height: 18px;">. </b>Look for "Other Devices" in the tree and right-click them one at time, selecting "Update driver...", then specifying the where you extract the CAB file. You'll be done in no time (well, half an hour!).</li>
<li><a href="http://windows.microsoft.com/is-IS/windows7/Create-a-restore-point">Create a Windows Restore Point</a> so you (probably) don't ever need to do this again!</li>
</ol>
<br />
<br />
<br />Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-72019206277620084322012-07-03T13:54:00.004-07:002012-07-03T13:54:50.216-07:00Saving up for a... sunny day?You may have heard the advice that you should have cash on hand to cover living expenses for some few months, just in case - "rainy day" money. This is very sensible, but... what about <i>sunny</i> days? <br />
<br />
Picture a perfectly cloudless June morning, as the gentlest of zephyrs whispers the fresh flush of newly-budded leaves and sends a cat's paws skimming across a lazy river. Living on a damp little patch in the mid-latitudes where one swirling low-pressure system follows another, remaining anchored to my desk on such a day is exquisite torture.<br />
<br />
So, my<span style="background-color: white;"> new savings goal: to arrive, without undue delay, at a point where sunny days are my own. Essentially, to achieve financial independence, to acquire, ahem, <i>feck off </i>money, to be... sort of retired, and to achieve this long before conventional carriage-clock age.</span><br />
<span style="background-color: white;"><br /></span><br />
<span style="background-color: white;">You will be asking the first question I asked...</span><br />
<div style="text-align: center;">
<br /></div>
<h4 style="text-align: left;">
<span style="font-weight: normal;"><i>
Can this be done?</i></span></h4>
With caveats, <i>yes it can</i>. As it turns out, having a good (but not remarkable) income combined with moderately frugal spending habits and the power of compounding investment gains makes it <i>completely</i> <i>possible</i>, and not even a particularly long-term project.<br />
<br />
Imagine an individual - Mr. Sensible - with net earnings of €100 per year, who is able to live on just €60. We will suppose that this frugal person invests the remaining €40 and achieves a return just under the long-term average for stock markets in developed countries - 8% per annum ( 9% including the dividends).<br />
<br />
Assuming smooth market returns (they are never smooth, of course, but that is for a later post), how many years do you think it will be before the annual investment gains exceed the €60 which Mr. Sensible needs to live on?<br />
<div style="text-align: center;">
<h4 style="text-align: left;">
<i style="background-color: white; font-weight: normal;">12 years!</i></h4>
</div>
This seemed a bit crazy to me when I first<a href="https://docs.google.com/spreadsheet/ccc?key=0Aqt_vqeIN5jKdFYzY2xLUEVwaThDeDBSNWpURTRMaXc#gid=0"> ran the numbers</a>, v If Mr. Sensible is able to retire after<i> 12 years</i> from a standing start, then why is the standard working life 40 or 45 years? Even assuming Mr. Sensible is being cautious, he can simply keep working and saving for another few years, at which point his own efforts are contributing less to his growing wealth than are his investment gains. <br />
<br />
So why aren't we all enjoying those sunny days with Mr. Sensible? <span style="background-color: white;">Two reasons:</span><br />
<ol>
<li>We spend too much (= save too little). Many people save nothing, or only 2% - 3% of their incomes.</li>
<li>When we save, we invest our money poorly (in a deposit account where inflation shrinks it slowly, or in a managed fund where the manager creams off enough fees and charges to keep returns well below market rate).</li>
</ol>
<div>
It really is that simple, and, over the next few posts, I'm going to explain how my sunny-day preparations in enough detail that you can do the same.<br />
<br />
<div style="text-align: center;">
~</div>
<br />
Some homework - I suggest these excellent resources:<br />
<a href="http://www.mrmoneymustache.com/">www.mrmoneymustache.com</a><br />
<a href="http://earlyretirementextreme.com/">http://earlyretirementextreme.com/</a>
</div>Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com1tag:blogger.com,1999:blog-8260279385614994872.post-72215801886419863632012-02-27T10:00:00.000-08:002012-02-27T10:00:07.549-08:00Android, Battery lifeSo, I switched to using an Android phone (<a href="http://www.gsmarena.com/samsung_i9001_galaxy_s_plus-3908.php">Samsung Galaxy S Plus</a>). Good move; I'm always connected, never lost, never bored... and never more than three feet from a power point. <i>Wow </i>do these 'droids love a steady supply of electrons. I've got USB charging points at the ready on my desk, in my car, in different rooms in my house. Even my boat has sprouted DC sockets to support this charging obsession.<div>
<br /></div>
<div>
Until a few days ago, when my once-permanent state of battery anxiety was cured, overnight, literally. I first tried, then within 24 hours paid for, <a href="https://market.android.com/details?id=com.latedroid.juicedefender&hl=en">Juice Defender</a>. Don't think of this as an App; think of it as a magical doubling/tripling of your €500 smart phone's battery capacity. €2 to do that? Absolutely unbelievable value for money. Just buy it.</div>Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-75479400259587774162011-12-23T03:11:00.000-08:002011-12-23T03:11:52.333-08:00Review of Speed Launcher (Android version)So, there is now an Android in my pocket; a <a href="http://www.google.ie/url?sa=t&rct=j&q=samsung%20galaxy%20s%20plus&source=web&cd=7&ved=0CG8QFjAG&url=http%3A%2F%2Fwww.gsmarena.com%2Fsamsung_i9001_galaxy_s_plus-3908.php&ei=SWH0TqDVDcT3rQe18sQH&usg=AFQjCNHm3qBuZKDzo53nF0XZOd-bUK_1Kg">Samsung Galaxy S Plus</a>. It is very shiny, with a lovely big bright screen. It navigates beautifully, makes a great games platform and a pretty fair web browser. It is a good way to check e-mail. It is much coveted. It takes lovely (HD!) video... and, sometimes, I even use it to make phone calls.<br />
<br />
And here is the strange thing. Every other phone I have owned was mostly a number pad. The designer, understanding that the thing was for phone calls, made it as fast and easy as possible to get those calls made. Your average Android, however essentially a very small tablet computer, with comparable processing and storage and only slightly fewer pixels on the screen. The making of phone calls is an afterthought - just another app that you might fit in between your browsing, mailing and gaming.<br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj5TZTVj5bo3VvVCVHknl5SOJ7HsR9UVmuURjexPKVeAH3JWNgBT60OvtcmRfKsgpJ2VWNSfRxyCmnx2CscwrljqFLdM6IS8I29u4lGYAp6343sOh3uCmOvtmscwOcICYgfPvokXT3maZU/s1600/speeddialler.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="156" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj5TZTVj5bo3VvVCVHknl5SOJ7HsR9UVmuURjexPKVeAH3JWNgBT60OvtcmRfKsgpJ2VWNSfRxyCmnx2CscwrljqFLdM6IS8I29u4lGYAp6343sOh3uCmOvtmscwOcICYgfPvokXT3maZU/s320/speeddialler.jpg" width="320" /></a></div>
<br />
<br />
So, actually making a call is a bit of a trek through the interface. First, there is the unlocking - one button push, followed by several swipes across that gorgeous screen; then there is the opening of the contacts app, the searching out of the contact, and finally, the choosing what to do with the contact - would sir like to phone, or e-mail, or text? Perhaps a video call?<br />
<br />
This is where <i>Speed Launcher</i> (available in <a href="https://market.android.com/details?id=com.speedlauncher">premium</a> and <a href="https://market.android.com/details?id=com.speedlauncher">lite (free)</a> versions) comes in. This app becomes your lock screen and gives you a rotary dial with slots for up to nine of your favourite contacts. Touch and spin, just like those analog rotary phones of olden times, and off you go. Other buttons in the center of the dial give speedy access to favourite apps and phone settings.<br />
<br />
Overall, I'm impressed. The spinning dial is a bit of a gimmick... but it is a pretty and <i>effective </i>gimmick. Go on - give it a whirl...<br />
<br />Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com1tag:blogger.com,1999:blog-8260279385614994872.post-80369230128130742952011-08-08T08:48:00.000-07:002011-08-08T09:10:56.614-07:00Wander Alarm<div>Dementia plays many an unkind trick; one of the more dangerous is wandering. When you find a parent or spouse leaving the house half-dressed in the middle of the night, it's clear you are very close to having a tragedy on your hands. </div><div>
<br /></div><div>No-one can stay vigilant <i>and </i>sleep; I needed a technical fix. I considered special locks, but I'm not happy with the idea of a door that can't be opened really quickly and easily in the event of a fire. Also, I wanted something subtle; I'm very sensitive to the indignities that dementia inflicts, and didn't want to add any conspicuous this-is-to-stop-you-escaping hardware.</div><div>
<br /></div><div>I finally settled on a wireless infrared motion detector which sets off a chime unit. I actually started drawing up a parts list so I could build one myself, but was relieved to find a ready-made version already for sale on Amazon, <a href="http://www.amazon.co.uk/Weatherproof-Wireless-Driveway-Burglar-Visitor/dp/B003ESV19E/ref=pd_sim_diy_12">sold as a handy way to detect arrivals</a> (burglars, customers) rather than departures. </div><div>
<br /></div><div>A month on, and I'm now confident the problem is solved. The sensors (wireless) were easy to install, the chime is loud, and the monitor is conveniently portable - whoever is "on duty" for the night can carry it to their bedroom.</div><div>
<br /></div>I was wrong about the "inconspicuous" bit, though: the man the alarm is intended to save now refers to it as "the Dad-catcher". Kind of a you've-got-to-laugh-or-you'ld-cry moment.Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-21808178876990329672010-10-27T01:50:00.000-07:002010-10-27T02:00:03.582-07:00Sugru hack saved my camcorder<div style="text-align: left;"><span class="Apple-style-span" style="font-family: arial, sans-serif; font-size: 13px; border-collapse: collapse; ">My first camcorder was just a little bit disappointing; the zoom lense was such that it could easily film far-away stuff (e.g. I could just about make out the whitening of the pole during a Martian winter), but the field of view was way too narrow for close-up stuff (e.g. my fast-moving toddler).</span></div><span class="Apple-style-span" style="font-family: arial, sans-serif; border-collapse: collapse; "><div style="font-size: 13px; "><br /></div><div style="font-size: 13px; ">I bought a wide-angle adapter, screwed it onto the filter threads on the front of the camcorder. Years of happy wide-angle filming followed... until my poor video camera drowned while surfing. I quickly bought a very similar model online... and was devastated to find that it couldn't take my old wide-angle adapter - in fact, it had no filter threads at all!</div><div style="text-align: center; font-size: 13px; "><br /></div><div style="font-size: 13px; ">Years of miserable narrow-angle filming followed. Then,<a href="http://sugru.com/"> along came Sugru!</a> The plasticine-like molding qualities and reasonable setting-time allowed me to mount my old adapter on my new camera (which had an awkwardly sloping non-perpendicular front end) and to get the optical alignment just right (I left the camera on while hacking so I could check for problems with focus or vignetting).</div><div style="font-size: 13px; "><br /></div><div style="font-size: 13px; "><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJTuKnb0rACSYKUpPsq-mvvaNOZKxfAt3HKdUYq6S18Y7HJ4FiUff5Ar_qWJNmIt7-1A7TGRyj9Z0de1kzmOX7X-8uwFCsdimnEM6Oa7-WfyMbXnUltQHrOMOzn1MU3OLhzqw0enpBxVI/s320/Sugru_Cam+002_lo_res.jpg" style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 320px; height: 240px;" border="0" alt="" id="BLOGGER_PHOTO_ID_5532647610028128114" /></div><div style="text-align: center; "><b><span class="Apple-style-span" style="font-size: small;">Wide-angle adapter mounted with (blue) sugru</span></b></div><div style="font-size: 13px; "><br /></div><div style="font-size: 13px; ">I'm thrilled with the result - the camera is maybe slightly less pretty, but I can squeeze a lot more world into each frame. My wide-angle adapter is now a permanent feature of my camera - and I like it that way.</div></span>Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-51622303590697425702010-08-03T09:05:00.000-07:002010-08-04T08:01:36.377-07:00Reviving an old laptop: Puppy LinuxWe have a shiny new laptop with a lovely wide screen and a multi-core processor; we love it very much and use it a lot. Meanwhile, our old laptop has been sitting idle - even when it would be handy to have a <span style="font-style: italic;">second </span>laptop handy for some really <span style="font-style: italic;">essential </span>web-browsing, we couldn't bear the eons-long boot-time and the extremely sluggish browsing experience that followed.<br /><br />That bothered me; I started out on a 386 with a 25MHz processor 2MB of RAM, back when that wasn't a bad machine. Now, a 1.6GHZ machine with 512MB of RAM is <span style="font-style: italic;">too slow</span> <span style="font-style: italic;">for me</span>? Insane! I could have re-installed Windows XP (again), and that would have helped; maybe added a little extra memory. Instead, I opted for something a little more radical: Linux. Now, once upon a time, Linux was <span style="font-style: italic;">scary</span>: an OS that was fast and stable, sure, but only for those who enjoy knitting their own device drivers of a winter's evening.<br /><br />No more! Today, a wealth of Linux variants awaits, and initially I was thinking in terms of Ubuntu or SUSE. However, my quest for speed pushed me to look for ever-smaller distributions (Linux variants), until I came upon <a href="http://www.puppylinux.org/">Puppy Linux</a> - which, like its namesake, is small, friendly, and fast-moving - the download is only around 100MB. Burnt to a CD, this cool little OS is ready to go; I just popped in my laptop's CD drive and <span style="font-style: italic;">was able to boot into Puppy Linux straight from the CD without even installing it</span>! I was very impressed to find that Puppy had no problem recognizing all my hardware, requiring absolutely no input from me to get the screen and speakers up and running - even my network and internet access via USB wifi dongle were handled easily - a far cry from my last Windows XP installation experience, which required much downloading of device drivers. Puppy is much friendlier than that!<br /><br />Puppy turned out to be very, very fast, extremely responsive, even on this old laptop. Being so small, the whole OS easily fits in RAM; no churning hard disks here. Puppy even comes pre-loaded with a decent web browser, word processor, spreadsheet, vector graphics app etc. - so you can do quite a bit without installing any other software (and all these applications are just as nippy as the OS itself). <br /><br />Having run Pupppy from the CD, I was totally sold; I copied all personal files onto a portable hard drive and nuked the laptop, opting for a clean Linux install (drastic, but easy to do). Now, that same old laptop we could hardly bear to use will boot from cold in 45 seconds flat. After that point, you can click something <span style="font-style: italic;">and have it launch instantly </span>- whereas Windows, in my experience, shows you the desktop as a placatory measure, while it continues frantically to load things in the background.<br /><br />In summary, reviving our old laptop with Puppy Linux was very easy and quick - much easier than re-installing Windows, and much cheaper than a hardware upgrade (it only cost me the price of a CD-R). My old machine is now an absolute pleasure to use, and I'm looking forward to filling up all the hard-disk vacated by Windows with some Linux-only apps I could never previously have run.Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-43982565101467405262010-07-28T14:27:00.000-07:002010-07-28T15:04:49.983-07:00Printing in 3D with Shapeways: a review<div style="text-align: left;">I still remember the magic of listening to my first printer (dot-matrix) clattering into life, and of watching as, ever so slowly, blank paper went in and printed words and pictures came out. It was an amazing moment of creation; how far removed from the painstaking effort of calligraphy or hand-sketching!</div><div><br /><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiFmgR3nuM8juVmthjy_aWpWgq8mGE_YdkLxA2V1KA3g7WNdlfEmg-0pCA6liIAFkbrx61is34J_STx5doCM5oH-umiKdE84bA8lPTqUhYOfn72GZwF_5xeeCmkO8ICbOGRBDGDDO5i4LI/s400/Ring+closeup_lores.jpg" style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 400px; height: 400px;" border="0" alt="" id="BLOGGER_PHOTO_ID_5499075202445085010" /></div><div style="text-align: center;"><b><span class="Apple-style-span" style="font-size: small;">One ring to bind them...</span></b></div><div><br /></div><div>Today, I opened a small cardboard box full of polystyrene chips and dug out a small packet. Within the packet, a single object, unique in the world. I had last seen it on my computer screen as 3D model which I created with the excellent <a href="http://moi3d.com/">NURBS modeller MOI (Moment Of Inspiration)</a>. This object - a simple wedding band - has been "printed" in 3D using a mixture of stainless steel and bronze, then sintered and finally gold plated, all by a company called <a href="http://www.shapeways.com/">Shapeways</a> operating in the Netherlands. The same company offer a variety of other materials, including several plastics and glass. They also offer some<a href="http://www.shapeways.com/blog/archives/522-New-Finshings-Gold-Plated-and-Antique-Bronze.html"> lovely metal finishes </a>apart from that pictured above (matt gold). For me, the combination of being able to make an object in a durable metal form, and to have the freedom to create my own one-of-a-kind was extremely exciting.</div><div><br /></div><div>So, how did it turn out?</div><div><br /></div><div><i>The good:</i> very easy to use. Upload your model, wait for them to check it can be printed, then choose a material and await delivery. My order (<a href="http://www.shapeways.com/detail?model=113274">this ring</a>) turned up well within their specified timeframe.</div><div><br /></div><div><i>The not-so-good: </i>3D printing is still in its infancy (and Shapeways are upfront about this), and, like my old dot matrix printer, the resolution is not yet pin-sharp. The digital model of the above ring is perfectly smooth, and the thin transverse pits are a product of the printing process. I like to think of it as<i> fattura</i>, the Italian term for the imperfections that reveal how a thing was made.</div><div><br /></div><div>Taking this service for what it is - a very accessible route to rapid manufacturing of small numbers of prototypes, toys, jewelry based on slightly experimental technology - and you will, like me, be a very happy customer. </div><div style="text-align: left;"><br /></div>Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-4231991733193072922010-07-21T13:20:00.000-07:002010-07-21T14:02:38.949-07:00Sugru: almost too much fun<div style="text-align: left;">I'm very enthusiastic about fixing broken things (some might say this could have something to do with how often I manage to break things). A steady stream of small repairs pass across my workbench - a little bit of carpentry, gluing, riveting, fibreglassing, etc.</div><div><br /></div><div><br /></div><div><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQCtAoiF3XrYCmhIxGEDb9AplMmB3thEdYOIUG6ny2xjHk7ok-pKa5B91nYDzOYgE9cVZM8E_6zYoKJ6RO2jI6RXWxy2mYcmeIS5xgECPEa66JDpiumoI8Hwyt8omGre7ORvXJM2h3ryU/s400/triptych.jpg" style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 400px; height: 178px;" border="0" alt="" id="BLOGGER_PHOTO_ID_5496465440785565538" /></div><div style="text-align: center;"><span class="Apple-style-span" style="font-size:small;"><b>Sugru in action</b></span></div><div><br /></div><div>Plastic, though, has always been a problem - until now. I've recently got a little packet full of sachets of a new "wonder material" from <a href="http://sugru.com/">Sugru.com </a>. The 50g sachets contain a material which looks and handles a lot like plasticene - very easy to shape and mold. Unlike plasticene, it starts to set about 30 minutes after coming out of the sachet. The really neat thing about it is that it sticks very well to whatever I've put it on. So far, I've repaired a screwdriver handle(plastic), a plastic basin with a long thin crack, a couple of long gashes on my brothers wetsuit (neoprene), and put a little blob on my gate (steel) to keep its bolt a little quieter.</div><div><br /></div><div>Any negatives? Well, it does come in sachets, so once you open one, it's a use-it-or-loose-it situation. So far though, this hasn't been much of a drawback - it is so easy and fun to use, you'll just be looking for things you can stick it to.</div><div><br /></div><div><br /></div>Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-16323248632505519552010-05-31T09:37:00.000-07:002010-06-16T00:14:31.842-07:00Making a rudder, part 4: designing gudgeonsWith my rudder blade is almost ready for the water, so time to think about it can connect to the boat. To hang it from <span style="font-style: italic;">Briongloid's</span> stern, I need to make a pair of gudgeons; these will allow it to pivot about a vertical axis, and need enough strength to prevent it either from being swept astern or from bobbing up out of the water (the Corecell interior being much less dense than water, the finished rudder is going to be quite buoyant, even with much of the length out of above the surface). Also, we are now talking about a moving part, and so friction is a problem: the gudgeon needs to pivot about a stainless steel pin without appreciable wear to either itself or the pin. Two separate mechanical challenges for our gudgeons: what materials should we use?<br /><br /><div><div style="text-align: center;"><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiayiOdT4c9AAm-Q018srbI3MMBf-cr0xjbFfcY0g3qgx9exiE3Hy9AMmhqKWgAlos1lDWAcPt74m-Ykrb4UhI9Z9QtdHSOuIwWHEjbPNtQQG3TkrVKY43CWAJMjOAIboqV6eSUoi_Pg6Q/s1600/rudder.png"><img style="display: block; margin: 0px auto 10px; text-align: center; cursor: pointer; width: 214px; height: 320px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiayiOdT4c9AAm-Q018srbI3MMBf-cr0xjbFfcY0g3qgx9exiE3Hy9AMmhqKWgAlos1lDWAcPt74m-Ykrb4UhI9Z9QtdHSOuIwWHEjbPNtQQG3TkrVKY43CWAJMjOAIboqV6eSUoi_Pg6Q/s320/rudder.png" alt="" id="BLOGGER_PHOTO_ID_5483264087879651026" border="0" /></a><span style="font-size:85%;"><span style="font-weight: bold;">Figure 1: Gudgeons (<span style="color: rgb(153, 153, 0);">yellow</span>) allow a transom-hung rudder (<span style="color: rgb(51, 102, 255);">blue</span>) to pivot about a vertical axis (<span style="color: rgb(255, 0, 0);">red</span>)</span></span><br /></div><br />To give the parts the necessary strength (tensile strength being what they need most), I have decided to imitate the gudgeons that held the old rudder, which were made in stainless steel and worked fairly well. However, I can't work in stainless steel (no skills, no tools, no materials), so I chose a different material, more impervious to corrosion and with even more impressive tensile strength: <a href="http://en.wikipedia.org/wiki/Carbon_fiber">carbon fibre</a> (weight for weight,<a href="http://www.wolframalpha.com/input/?i=carbon+fibre+tensile+strength"> the median sample of carbon fibre</a> has six times the <a href="http://www.wolframalpha.com/input/?i=stainless+steel+tensile+strength">tensile strength of stainless steel</a> <span style="font-size:85%;">[Source: <a href="http://www.wolframalpha.com/">Wolfram Alpha</a>]</span>. This can be bought as a woven fabric, just like fibreglass, and worked with the same simple tools - epoxy resin, a pair of scissors, etc (Kevlar needs special shears, but ordinary scissors will do for "mere" carbon fibre). Strength problem: solved.<div><br /><div>So much for strength: what about friction? This is a <span style="font-style: italic;">moving </span>part, a type of bearing, and Mr. Friction is not our friend. The pivoting action of the gudgeon around the steel pin is going to cause wear if I just use epoxy-impregnated carbon fibre. For the core of the bearing, a different material is required - strong, but also slippy. After some research, I found the solution <a href="http://f22build.blogspot.com/2009_02_01_archive.html">on the excellent blog of a Canadian who is building "Raven"</a>, a nippy trimaran from <a href="http://www.f-boat.com/pages/trimarans/F-22.html">Ian Farrier's F22 design</a>. This gentleman used a plastic PET-P, Polyethlyene Terypthalate, also sold as Ertalye, in just the same situation. This particular wonder material shrugs off water, is nice and slippy, and and also pretty strong. With a little research, the amateur builder can buy small quantities in rod or sheet form. Just the thing for the core of our bearing.<br /><br /><div style="text-align: center;"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJ3OCA4ncbjujP_Xy_mRLt6RHhgCdt0j7WlXQcQPHl8XvTW2gGlqng6TqLeqy4rKzz74ZSopL-HEGW4KL61Rc2b6TZYK22C1Ykc3DEvxdHMlCUjFgmMFlKpes1A_6twfNxJzzz0kJs3rE/s320/gudgeon+core.png" style="display: block; margin: 0px auto 10px; text-align: center; cursor: pointer; width: 320px; height: 231px;" alt="" id="BLOGGER_PHOTO_ID_5481262493397441010" border="0" /></div> <div style="text-align: center;"><span class="Apple-style-span" style="font-size:85%;"><b>Figure 2: Gudgeon cores (carbon fibre ties not pictures)</b></span></div> <div><br /></div><div><b>Figure 2</b> above illustrates the core of the gudgeons, with the long base of the triangle being mounted on the leading edge of the rudder itself. Layers of carbon fibre cloth around the outside bind the core to the rudder in a continuous loop for maximum strength. The hardwood insert is there just to save some epoxy (cut from the ruined old rudder, it saves me a few pence worth of epoxy and provides similar strength). The hole in the centre of the PET-P cylinder is where the pintle goes, so the gudgeon can fulfil its pivoting function.</div><div><br /></div><div><i>Coming in the next post: making and mounting the gudgeons<br /><br />Previous posts in the series:<br /></i><a href="http://bluejotter.blogspot.com/2009/06/designing-new-rudder.html" style="font-weight: bold; font-style: italic;">Designing a rudder, part 1</a><br /><a href="http://bluejotter.blogspot.com/2009/06/designing-new-rudder-part-2.html"><span style="font-weight: bold; font-style: italic;">Designing a rudder, part 2</span></a><br /><a href="http://bluejotter.blogspot.com/2009/08/making-new-rudder-part-1.html" style="font-weight: bold; font-style: italic;">Making a rudder, part 1</a><br /><div><a href="http://bluejotter.blogspot.com/2009/09/making-new-rudder-part-2.html"><span style="font-weight: bold; font-style: italic;">Making a rudder, part 2</span></a><br /><a style="font-style: italic; font-weight: bold;" href="http://bluejotter.blogspot.com/2009/10/making-new-rudder-part-3.html">Making a rudder, part 3</a><br /></div><br /></div><div><br /></div></div></div></div>Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-56470807714873156542010-04-11T13:11:00.000-07:002010-04-11T13:56:11.157-07:00Taking the long way around<div><i>In which no rudders are mended, but some beautiful footage is watched.</i></div><div><br /></div>As the weather finally warms enough for epoxy to set and my boat repairs to continue, I'm looking forward more and more eagerly to (re)launch day. Until then, perhaps the next best thing is to watch a man called <a href="http://www.keepturningleft.co.uk/index.php">Dylan Winters circumnavigating Britain</a>, very slowly in "the slug"<a href="http://home.kpn.nl/mirroroffshore/">, a Mirror Offshore</a> (19 feet, with inboard diesel, designed by Van de Stadt, the same man who designed my own poor <i>Briongloid)</i>.<div><br /></div><div>What makes an already-ambitious trip even longer and more impressive is that Mr. Winters is not taking the shortest route. Instead, he sails as far as possible up every river of interest along the way - from giants like the Thames, to tiny backwaters like <a href="http://en.wikipedia.org/wiki/Beaumont_Cut">Beaumont Qua</a>y (up a canal dug by slaves in Roman times). Along the way, he takes beautiful HD footage of boats large and small - lately, gorgeous <a href="http://en.wikipedia.org/wiki/Thames_sailing_barge">Thames barge</a>s have been a recurring them. </div><div><br /></div><div>A professional film-maker and seasoned editor, his films come with illuminating commentary on the history of the places he visits, and his lovely shots of sea and river are complemented by lovely soundtrack by the likes of <a href="http://www.trackitdown.net/genre/house/track/620483.html">Cities of Foam</a>. </div><div><br /></div><div>Enough talking; if you take even a passing interest in things boaty or the British coastline, do yourself a favour and wander over to <a href="http://www.keepturningleft.co.uk/index.php">Keep Turning Left</a>. Well worth the price of admission.</div><div><br /></div><div><br /></div>Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-53371530444677264932009-10-10T15:05:00.000-07:002009-10-10T15:37:28.956-07:00Making a new rudder, part 3<a href="http://bluejotter.blogspot.com/2009/06/designing-new-rudder.html" style="font-weight: bold; font-style: italic; ">Designing a rudder, part 1</a><br /><a href="http://bluejotter.blogspot.com/2009/06/designing-new-rudder-part-2.html"><span style="font-weight: bold; font-style: italic; ">Designing a rudder, part 2</span></a><br /><a href="http://bluejotter.blogspot.com/2009/08/making-new-rudder-part-1.html" style="font-weight: bold; font-style: italic; ">Making a rudder, part 1</a><br /><div><a href="http://bluejotter.blogspot.com/2009/09/making-new-rudder-part-2.html"><span style="font-weight: bold; font-style: italic; ">Making a rudder, part 2</span></a></div><div><br /></div><div>After lots of careful shaping of details (mostly with an orbital sander) and filling in the odd accidental gouge (using a mixture of epoxy and colloidal silica - which sets into a very tough and water-impervious substance), I was nearly ready to laminate.</div><div><br /><table style="text-align: left;width: auto; "><tbody><tr><td style="text-align: left;"><a href="http://picasaweb.google.com/lh/photo/S39xgO2c3kU285pmBip90g?feat=embedwebsite"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhOaNfLKNXy7tYOEPR58V-OdqcpyppIV6n1TpCzz787BF75DociTXQlZachud69k_s0lAOF1aC1PWlHTv9SMLxALVsHKf79itNTWfsAfYUsJ8wVu4TmejxeLpyqv9paTHk3ewbDdiFJBn8/s144/IMG_6866.JPG" /></a></td></tr><tr><td style="text-align: left;font-family: arial, sans-serif; font-size: 11px; ">From <a href="http://picasaweb.google.com/dixon.edward/LaminatingNewRudder?feat=embedwebsite">Laminating new rudder</a></td></tr></tbody></table><b><div style="text-align: left;"><span class="Apple-style-span" style=" ;font-size:small;">Hardwood inserts epoxied in place, ready to take bolts</span></div></b></div><div style="text-align: center;"><br /></div><div>The final pre-lamination step was to drill big holes where the bolts connecting rudder to yacht will later sit, out to a radius of 5 times the bolt size: since Corecell is too soft to hold stainless steel bolts, I fixed hardwood inserts (chiseled from the remains of my old rudder) in place with lots of epoxy/colloidal silica mix to fill the gaps (actually, the wood was not technically necessary - but cheaper than epoxy, and a nice link with the old rudder, so in it went). Now, my rudder is a wood/corecell/epoxy/colloidal silica composite - and we've not even started with the glass fibre yet. </div><div><br /><br /><table style="width:auto;"><tbody><tr><td><a href="http://picasaweb.google.com/lh/photo/JSn2645KLKOT92rBbP1jBA?feat=embedwebsite"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0MNQz19sB23cw4X47IfWZc77wJwh6od4exxBquKO0Q83oDj4OlXt53zBC-tkZZ0AmITmW-wJY_2TSsgjqXU6aoqeAIJK1khqS8t_nmE3-f5MCPeUa-aEqwN3DH5ujytaDqQ6SBP59FJY/s144/IMG_6864.JPG" /></a></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From <a href="http://picasaweb.google.com/dixon.edward/LaminatingNewRudder?feat=embedwebsite">Laminating new rudder</a></td></tr></tbody></table><b><span class="Apple-style-span" style="font-size:small;">Rudder core, fully shaped, smoothed, faired, and ready for lay-up</span></b></div><div><br />Next step was to cut glass cloth to size; this is beautiful stuff - layers of four-harness satin alternating with heavy unidirectional fabric. It isn't that easy to cut, especially the 500g/metre stuff - glass is really hard. Also, the material looks almost too beautiful to use.</div><div><br /></div><div><br /><table style="width:auto;"><tbody><tr><td><a href="http://picasaweb.google.com/lh/photo/o5w9RIK36JeV56iezPROFQ?feat=embedwebsite"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkm0-MDsWaeK7cnnVz1iocHw95Ht1BlZurl2K0vKs1olvcEcQkbVa1jtRuLvt-dk8j4Xa6gFun1FCDM74OPAlZjPH56Rma1Yk1waCGyiwyClak9f-vLJVXRyudh9n3Rf09ZLYxjBfQSbc/s144/IMG_6881.jpg" /></a></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From <a href="http://picasaweb.google.com/dixon.edward/LaminatingNewRudder?feat=embedwebsite">Laminating new rudder</a></td></tr></tbody></table><b><span class="Apple-style-span" style="font-size:small;">Unidirectional glass fabric, 500g/square metre</span></b></div><div><br /></div><div>Before laminating, I need to don my protective gear - epoxy is great stuff, but not for the human body. I always wear eye protection in case of silly accidents, nitrile gloves (I'm now using cheap disposables instead of the heavy duty items pictured - latex won't do, by the way), rubber boots (because there are always drips and spatters), overalls (well, duh!) and an apron (because I tend to lean against the workbench, and my overalls nearly soaked through once).</div><div><br /></div><div><br /><table style="width:auto;"><tbody><tr><td><a href="http://picasaweb.google.com/lh/photo/J49iHXQbTFw4sBkc4IA5OQ?feat=embedwebsite"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiR9D9ZLeLoKUv_z_7J8jpcOkHpX340WuwyJa2F-ItkmQbsY6_V2S44kT_tn-acPg9zIDPexd7qkpDj4gj_n8fjXKksmIxPKFcc_DS3WsKOlK0paAZO8E-NlgXP_IwmyeaTDGrsGEC1e6g/s144/IMG_6890.jpg" /></a></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From <a href="http://picasaweb.google.com/dixon.edward/LaminatingNewRudder?feat=embedwebsite">Laminating new rudder</a></td></tr></tbody></table><span class="Apple-style-span" style="font-size: small;"><b>Ready for Fun with Chemicals</b></span></div><div><br /><table style="text-align: left;width: auto; "><tbody><tr><td style="text-align: left;"><a href="http://picasaweb.google.com/lh/photo/4ac9mgFdg9thINIdUkvSuQ?feat=embedwebsite"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEilTcI06oZLv8TaWz0eWPrKhBgQ4rJ7mX3tgNrreVj_R04jmvY9PLekVx1oPbGjWq08sKHSw12vwAMXZvXWTI6DaaG5XyBH34rs7wiObjSebSV04aVkKDTefcpaXhrFrfym5cs0gLy2Mb8/s144/IMG_6872.JPG" /></a></td></tr><tr><td style="text-align: left;font-family: arial, sans-serif; font-size: 11px; ">From <a href="http://picasaweb.google.com/dixon.edward/LaminatingNewRudder?feat=embedwebsite">Laminating new rudder</a></td></tr></tbody></table><b><span class="Apple-style-span" style="font-size:small;">Wet fabric (transparent) draped over the rudder core</span></b></div><div><br /></div><div>My first couple of layups went pretty well - except I laid the epoxy on way too thick; extra does not add extra strength, only weight - and it is pricey stuff to be wasting. In the picture above, note the puddles of excess epoxy sitting on top of the cloth, and the messy ends at the rudder head (beside the squeegee) that I had to grind off after the resin had set. Hard to see, but important: the plywood workbench has been covered in white-faces hardboard (cheap enough to bin later) which in turn has been covered with a transparent polyethelene sheet (does not stick to epoxy).</div><div><br /></div><div>Miscellaneous tips:</div><div><ul><li>Clean your squeegee straight after use, while the resin is still soft</li><li>Buy a set of cheap brushes from Tesco for dabbing on resin wherever dry spots show up (€1.25 gets you 3 brushes in our local). Ditch after use (too hard to clean).</li><li>Disposable nitrile gloves give great tactile feedback - actually better than the heavy kind (plus, no clean-up). Very, very cheap at B&Q - and <i>insanely </i>cheap on E-bay.</li><li>It is much easier to use too much resin than too little</li><li>...but you still need to keep an eagle eye for dry spots.</li><li>take your time and do careful work - resin sets fast, but not <i>crazy </i>fast</li><li>use peel ply - leaves a lovely smooth easy-to-work with surface, helps remove excess resin, well worth the money</li><li>an ounce of preparation (masking tape, polyethylene sheets, etc.) saves a ton of fixing up later</li></ul></div><div><br /></div>Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-55583249613788878472009-10-08T14:16:00.000-07:002009-10-09T07:06:49.962-07:00Toys<div style="text-align: left;">Our son has reached The Age of Exploration. At last, he can pull himself upright and toddle along on his hind paws - so long as a support of some kind remains within reach. To give him some walking practice and a little independence, I sketched out a pushing/walking toy, then started digging through our wood-pile. Soon, odds and ends had been sawed and screwed into something closely resembling the sketch below (the height for the bars chosen to be just around our son's shoulders, low enough to be pushable, too high to fall over). One point to note: sanding off all edges and any rough surfaces will save grief later. With even a very cheap random orbital sander, this does not take long. <br /></div><div style="text-align: left;"><br /></div><div><br /></div><div><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgFBFAp03YvDjlblYAhAAAHmC2KvD_f5vEHp5PHMIhDC5rGj7QEPvMmv4qqZNxt6kifM4tJAGphRrkrt9W7F3rCV4ZLv2MWN_-S-iGulmTkdR971IY8GCMEtT-PXGL1YMMy_I1ncTXq8OM/s1600-h/Pusher+1.jpg"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgFBFAp03YvDjlblYAhAAAHmC2KvD_f5vEHp5PHMIhDC5rGj7QEPvMmv4qqZNxt6kifM4tJAGphRrkrt9W7F3rCV4ZLv2MWN_-S-iGulmTkdR971IY8GCMEtT-PXGL1YMMy_I1ncTXq8OM/s200/Pusher+1.jpg" alt="" id="BLOGGER_PHOTO_ID_5390343726289466322" style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 200px; height: 184px;" border="0" /></a></div><div style="text-align: center;"><b><span class="Apple-style-span" style="font-size:small;">Version 1: Sled with upright handle</span></b></div><div style="text-align: center;"><span class="Apple-style-span" style="font-size:small;"><b><br /></b></span></div><div>Full of anticipating, I presented the result of my labours to my son, who got the idea of the toy straight away, and set off at high speed, cackling with glee... and seconds later, rammed it a cupboard dead-on. No damage done, but also, no possibility of turning. The next problem was that he stood <i>inside </i>the sled, and tried to pull it over his own toes.</div><div><br /></div><div><br /></div><div><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEis8ySrX4ULQpRgKYQ0enS5V4JBBZ15W3L790XEGfogJXgMpzfB_J0GkjcI2Vt4Thm3uzcfa2ZAxnjEV-yYUULonpSrpvZpnI5-DabCvDI4KpSPTAbhTQeNRmM9IP0Hc40VUI0Pkx2SnEg/s1600-h/Pusher+2.jpg" style="text-decoration: none;"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEis8ySrX4ULQpRgKYQ0enS5V4JBBZ15W3L790XEGfogJXgMpzfB_J0GkjcI2Vt4Thm3uzcfa2ZAxnjEV-yYUULonpSrpvZpnI5-DabCvDI4KpSPTAbhTQeNRmM9IP0Hc40VUI0Pkx2SnEg/s200/Pusher+2.jpg" alt="" id="BLOGGER_PHOTO_ID_5390343853591305138" style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 200px; height: 184px;" border="0" /></a></div><div style="text-align: center;"><b><span class="Apple-style-span" style="font-size:small;">Version 2: platform to stand on, double-ended</span></b></div><div><br /></div><div>I decided to solve the turning/reversing problem by making the pusher double-ended, duplicating the existing upright handle, and solved the standing-in-the-middle problem with a plywood platform. As I finished screwing this on, it occurred to me that I should have used bolts to secure the uprights to the base - then it would be very easy to take the whole thing apart into flat pieces for storage or transport.<br /><br />The modifications were well received by my tiny test pilot: he used an upright to pull himself to his feet, then clambered grinning onto the platform, and tugged mightily at a handle, doing his best to rock the whole contraption. Which gave Dad an idea.</div><div><br /></div><div><br /></div><div><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhtt64e2j90fx2NoFcmhetilqdSWIP1MJL33KDdb_ph9-dMfe0y3hL2AD7pyFEPFPaQccPyiaHjOpTnCxzvNO2Q1Euxl4ZWtGopb49B2h0VvWQria3b7Hd1nldhiHBKmxLGAq7BTsvQCWU/s1600-h/Pusher+3.jpg"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhtt64e2j90fx2NoFcmhetilqdSWIP1MJL33KDdb_ph9-dMfe0y3hL2AD7pyFEPFPaQccPyiaHjOpTnCxzvNO2Q1Euxl4ZWtGopb49B2h0VvWQria3b7Hd1nldhiHBKmxLGAq7BTsvQCWU/s200/Pusher+3.jpg" alt="" id="BLOGGER_PHOTO_ID_5390343957441555458" style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 200px; height: 184px;" border="0" /></a></div><div style="text-align: center;"><b><span class="Apple-style-span" style="font-size:small;">Version 3: build-in rocking function!</span></b></div><div><br /></div><div>The final (so far) modification required some fairy delicate wood shaping: I made a long shallow curve from a single piece of wood, sawing, chiseling, sanding, then split it lengthwise into two identical pieces, which I glued with ordinary wood glue (do not risk snagging a screw head on your partner's tiles/carpet!) carefully to the existing runners, then clamped and allowed to set overnight.</div><div><br /></div><div>Next morning, a very proud Dad presented his soon with the push-me-pull-you version. Son discovered that the new version made a very pleasing racket as it rocked on the kitchen tiles, and Dad was relieved to find that he hadn't overdone the rocking motion (no danger of head-over-heels).</div><div><br /></div><div>This has been my first real foray into toy-making, at least as an adult; my son has got a lot of fun and exercise from a very simple toy, and I just as much, from the pleasure of making, of giving, and of seeing <i>his </i>fun. </div><div><br /></div><div>Dads, Mums, Aunties and Uncles: to your sheds! Go build!</div><div><br /></div>Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-42721497280394000752009-09-20T13:40:00.000-07:002009-09-21T03:20:09.145-07:00Making a new rudder, part 2<span style="font-weight: bold; font-style: italic;">This post is part of a series on making a fibreglass rudder with a foam core:</span><br /><a style="font-weight: bold; font-style: italic;" href="http://bluejotter.blogspot.com/2009/06/designing-new-rudder.html">Designing a rudder, part 1</a><br /><a href="http://bluejotter.blogspot.com/2009/06/designing-new-rudder-part-2.html"><span style="font-weight: bold; font-style: italic;">Designing a rudder, part 2</span></a><br /><a style="font-weight: bold; font-style: italic;" href="http://bluejotter.blogspot.com/2009/08/making-new-rudder-part-1.html">Making a rudder, part 1</a><br /><br />Calculations done, foam cut into neat rudder-sized rectangles, I had no alternative but to start shaping the foam. I did it like this...<br /><br /><span style="font-weight: bold;">Step 1:</span> mark the depth of foam to be removed. I did this by setting a circular saw to the calculated depth for a given point in the profile, then running it the length of the rudder. I kept the trenches very close together at the leading edge of the foil - the first few tracks were only 2mm apart (the saw blade width), then, as the slope of the foil changed more slowly 4mm, 5mm, 10mm. On the rear half of the foil, whose slope is almost straight, the gaps increased to 20mm, then 40mm. With all the tracks cut, I sprayed blue paint into the cuts, making sure to get good coverage on the bottoms of the tracks.<br /><br /><span style="font-weight: bold;">Step 2:</span> remove the bulk of the foam. I tried chisels: bad idea. What worked <span style="font-style: italic;">really </span>well was to take a wood saw, hold it sideways and cut along the foil at a shallow angle, keeping a millimetre or two above the bottom of the trenches. In about 40 minutes I was able to remove most of the excess foam, leaving behind a nice flat surface.<br /><br /><div style="text-align: center;"><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEju9ZHlFAeRoCL0Afjm64GV-ra0WAnsT_BMnZ82J-KKXD0edRCJWaHooH6U-iaeRN5Hr8k0IOF7WoffHflBMMpLXStij3x3yXWAvCsGJ5DFC77hZmY8OAukHISsKmqkDjDbRDqs5pEhgOU/s1600-h/RudderMaking-009.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 305px; height: 320px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEju9ZHlFAeRoCL0Afjm64GV-ra0WAnsT_BMnZ82J-KKXD0edRCJWaHooH6U-iaeRN5Hr8k0IOF7WoffHflBMMpLXStij3x3yXWAvCsGJ5DFC77hZmY8OAukHISsKmqkDjDbRDqs5pEhgOU/s320/RudderMaking-009.jpg" alt="" id="BLOGGER_PHOTO_ID_5383672492857117346" border="0" /></a><span style="font-size:85%;"><span style="font-weight: bold;">Saws make short work of Corecell</span></span><br /></div><br /><span style="font-weight: bold;">Step 3:</span> the saw was followed by a wood plane, which cut to within 1-0.5mm of the trench bottoms - but not lower, because the plane did not cut the foam as smoothly as wood, tending to leave the surface a little rough.<br /><br /><span style="font-weight: bold;">Step 4:</span> I next used a<a href="http://en.wikipedia.org/wiki/Surform"> surform</a> to remove the last of the excess foam, leaving the surface of the foil flush with the trench bottoms.<br /><br /><span style="font-weight: bold;">Step 5:</span> To get a really smooth finish, I followed up the <a href="http://en.wikipedia.org/wiki/Surform">surform</a> with a <a href="http://en.wikipedia.org/wiki/Random_orbital_sander">random orbital sander</a>.<br /><br /><br />With the two halves shaped and (I hoped) pretty symmetrical, I mixed up 250mm of epoxy, then stirred in enough colloidal silica (amazingly fine white powder) to make a paste with a honey-like consistency. A squeegee was perfect for getting an even spread on the flat side of the starboard foil half. Interesting to note: although the foam <span style="font-style: italic;">looks</span> like a sponge, it certainly doesn't act like it - it doesn't the epoxy in, but leaves it on the surface - where I need it .<br /><br /><br /><div style="text-align: center;"><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhToUeIOAkwVhos4j36Pp_r5Qv_TeiyiDqj6XUhzYpmA4j24sjyjcHBx1cutV0FHkTpkc1QRnYnWSW0iewvT_ePBI2PyKhZivFHrQbyI581L0r-sdYBvJ-qEiWynvgIT5Hv0YDL1pIUuhc/s1600-h/RudderMaking-015.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 310px; height: 320px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhToUeIOAkwVhos4j36Pp_r5Qv_TeiyiDqj6XUhzYpmA4j24sjyjcHBx1cutV0FHkTpkc1QRnYnWSW0iewvT_ePBI2PyKhZivFHrQbyI581L0r-sdYBvJ-qEiWynvgIT5Hv0YDL1pIUuhc/s320/RudderMaking-015.jpg" alt="" id="BLOGGER_PHOTO_ID_5383672501086718082" border="0" /></a></div><div style="text-align: center;"><span style="font-weight: bold;font-size:85%;" >Rudder core halves clamped together; polythene drapes keep epoxy off the worktop</span><br /></div><br />With an even spread of epoxy covering the starboard half, I dropped the port half into position, and applied my entire collection of clamps. You never have enough clamps. And that was it for the day: all going well, by tomorrow morning, the two halves will be one - permanently.Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-57911422022282361072009-09-18T15:51:00.001-07:002009-09-18T16:20:51.237-07:00Long Ears<div style="text-align: left;">In the morning, there was a small brown scrap on our lawn where none had been before. Turning over, as I thought, the corpse of a headless bat, I was startled by squeaks of fear or rage. The mouse-sized animal had curled its wings in tight around its body, and tucked its head into its chest; even its ears had curled up, looking something like a ram's horns. The face was relatively pretty, as bats go, without the weird pressed-up nose that some species have; the massive ears are the feature you'll remember, though.</div><div><br /></div><div><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhYzT0l8vU7pWfvtK1YTi2de8xkeSzwZG4F-Ih8n9Bjk9vTD6M7xXhB2nmGzfDeE-0Gw9uVl-GdOESGWuR-svpnmmtRCZxPBxEdKTJjcWin_3gxcL0kL34GXeufDsuy47FYVeYOcq3CQVk/s320/Brown+Long+Eared+Bat+On+Tree.jpg" style="display:block; margin:0px auto 10px; text-align:center;cursor:pointer; cursor:hand;width: 210px; height: 320px;" border="0" alt="" id="BLOGGER_PHOTO_ID_5382946882966038818" /><div style="text-align: center;"><span class="Apple-style-span" style="font-size: small;"><b>Brown long-eared ba</b></span><b><span class="Apple-style-span" style="font-size: small;">t</span></b></div></div><div><br /></div><div><br /></div><div>According to the excellent <a href="http://www.amazon.co.uk/Exploring-Irish-Mammals-Tom-Hayden/dp/1860590934">"Exploring Irish Mammals"</a>, Plecotus auritus, described by Linaeus in 1758, is found across most of Europe north of the Pyreness, and also in the far east, in regions within Russia, China, and Japan. This bat likes to "foliage glean", plucking its prey from leaves or even the ground as it flys.</div><div><br /></div><div style="text-align: center;">~</div><div><br /></div><div>My tiny specimen was soaked in dew, and motionless - this last must be what saved it from our cat, who <i>loves </i>to chase, but tires of prey which can no longer flee. I tucked my patient away for the day in an empty toolbox, with a few crumbs of cat food for sustenance.</div><div><br /></div><div style="text-align: center;">~</div><div><br /></div><div>After sunset, I took my patient for a walk, to a wooded and cat-free place. Out of the toolbox, the ears inflated and the head looked up; then, the tiny creatures crawled from my gloved hand onto the rough bark of a large tree, hooking on tight with claws on the leading edge of the wing, while black and hand-like hind paws sought purchase.</div>Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-26819103798828958012009-08-25T09:33:00.000-07:002009-09-21T03:18:29.274-07:00Making a new rudder, part 1<span style="font-style: italic;">Following on from the previous posts <a href="http://bluejotter.blogspot.com/2009/06/designing-new-rudder-part-2.html">on the design of rudder foils,</a> our hero now begins the tricky fabrication stage.</span><br /><br />As<a href="http://bluejotter.blogspot.com/2009/06/designing-new-rudder-part-2.html"> discussed previously</a>, my new rudder will have a fibreglass skin (6 layers) wrapped around a foam core. Not just any old foam - <a href="http://www.gurit.com/sector_introduction.asp?section=0001000100220016&sectionTitle=Corecell%99+-+Structural+Core+Materials+from+SP">Corecell</a>, a light, stiff material that is absorbs little resin (or water) and will contain any damage to a very localised area. It won't rot, delaminate or crack, and the sheet I bought from the helpful folk at <a href="http://www.mid.ie/">MID</a> has a density of just 60kg / cubic metre.<br /><br />I've never used this material before, so wasn't sure how easy it would be to work with. First, I trimmed the lengths I needed for the rudder itself from the original 4ft by 8ft x 25mm sheet using a jig saw. No problems, and surprisingly little dust - most of the material from the<a href="http://www.merriam-webster.com/dictionary/kerf"> kerf</a> seemed to stick together, hinting at one potential difficultly: since this foam is a very good insulator, heat from cutting tools disspates slowly - so cutting at higher speeds can cause melting.<br /><br />Next, I used an off-cut to practice my foam-shaping skills (never shaped foam before, didn't want to start by destroying my proto-rudder). First, I clamped a straight-edged piece of wood atop the foam as a cutting guide (straightness verified against a handy glass window - float glass is very flat). Then, I set the cutting depth on my hand-held circular saw and cut a series of trenches in the foam, the depths calculated from my spreadsheet describing the NACA 0012 foil I want to make.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEihUqNvWX7gf0OKsDef_hhzomZlifHdJTHfX1cQvT-dnxutEU1Qz71mMuvEik3EPhyF40ft6YlN1PzoUXAlWsoAbkwEu97yhg_vCgyM1d9k5gWwBr8fUemKyqDhX9idqAVruTrKynlZd7U/s1600-h/DSC00270.JPG"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 240px; height: 180px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEihUqNvWX7gf0OKsDef_hhzomZlifHdJTHfX1cQvT-dnxutEU1Qz71mMuvEik3EPhyF40ft6YlN1PzoUXAlWsoAbkwEu97yhg_vCgyM1d9k5gWwBr8fUemKyqDhX9idqAVruTrKynlZd7U/s200/DSC00270.JPG" alt="" id="BLOGGER_PHOTO_ID_5373943436938911474" border="0" /></a><br />Next, I sprayed the yellow foam with blue paint, making certain it penetrated to the bottom of the trenches.<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqz5uMlbiudBTjTLqs8B7taX-tsnZnmF7MQ8KmdL-X4MkTIB30XqHJFiKOG6Wq45szWvwDwniX9EDCXq4MbIyep8HW9AvqKPWceOQCJuivWwzTpqI6dtqtdQjaL6LWR8qoZnihtQuJaww/s1600-h/DSC00274.JPG"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 240px; height: 180px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqz5uMlbiudBTjTLqs8B7taX-tsnZnmF7MQ8KmdL-X4MkTIB30XqHJFiKOG6Wq45szWvwDwniX9EDCXq4MbIyep8HW9AvqKPWceOQCJuivWwzTpqI6dtqtdQjaL6LWR8qoZnihtQuJaww/s200/DSC00274.JPG" alt="" id="BLOGGER_PHOTO_ID_5373943603360701570" border="0" /></a><br />Once the blue paint was on, it was now "safe" to start cutting away excess foam; I tried a random orbital sander, but, especially at high revs, discs clogged too quickly. Tried a sharp penknife: not too useful. A block plane worked reasonably well, and a rasp/file came in very handy for tidying up small irregularities. The paint worked a treat - you can see below how the blue lines allow me to be sure I've not removed too much material.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg3uwAFYvFxvMrjo1vHJtOM1OaBS7etBUIjT5fofiNW1QxNcG5xrAN9Nb3kWvFQGkCFFQLxykmYBzExCavSlVPmPM4uUye58fiB1XeC7n9AKIXP64cx09IVMwCwnRqUTCOGa29i4gdg0m4/s1600-h/DSC00278.JPG"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 240px; height: 180px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg3uwAFYvFxvMrjo1vHJtOM1OaBS7etBUIjT5fofiNW1QxNcG5xrAN9Nb3kWvFQGkCFFQLxykmYBzExCavSlVPmPM4uUye58fiB1XeC7n9AKIXP64cx09IVMwCwnRqUTCOGa29i4gdg0m4/s200/DSC00278.JPG" alt="" id="BLOGGER_PHOTO_ID_5373944246235526466" border="0" /></a><br />Shaping the leading edge of the foil was quite easy; shaping the trailing edge - much more material to remove, but accuracy is less crucial - turned out to be more difficult. I actually tried chiseling, which worked up to a point, but was slow and difficult. Not sure about the best way to do this yet - I hope to try an angle grinder soon to slice the bulk off, then follow that with plane, disc sander and rasp for the final finish.<br /><br />Conclusions so far: Corecell <span style="font-style: italic;">is </span>very easy to cut. Shaping it is much easier than shaping wood, but the same techniques won't work.<br /><br /><span style="font-weight: bold; font-style: italic;">This post is part of a series on making a fibreglass rudder with a foam core:</span><br /><a style="font-weight: bold; font-style: italic;" href="http://bluejotter.blogspot.com/2009/06/designing-new-rudder.html">Designing a rudder, part 1</a><br /><a href="http://bluejotter.blogspot.com/2009/06/designing-new-rudder-part-2.html"><span style="font-weight: bold; font-style: italic;">Designing a rudder, part 2</span></a><br /><a style="font-weight: bold; font-style: italic;" href="http://bluejotter.blogspot.com/2009/08/making-new-rudder-part-1.html">Making a rudder, part 1</a>Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com2tag:blogger.com,1999:blog-8260279385614994872.post-17750599305600221962009-07-06T06:53:00.000-07:002009-07-06T08:39:17.811-07:00Astronavigation / Celestial Navigation, Part 2Last night, a (briefly) clear sky gave me a chance to try a key element of practical celestial navigation. Following the example of <a href="http://www.globestar.org/marvin_creamer.htm">Marvin Creamer </a>and countless forgotten sailors of the pre-sextant era, I attempted to measure the altitude of some celestial bodies using no instruments whatsoever (partly because, aside from my telescope, I haven't made or bought any yet).<br /><br />Why no instruments? Obviously, this decreases the accuracy of the observations that you can make; not so obviously, it is still possible to be accurate enough to make measurements that are accurate enough to be useful. Marvin Creamer made fairly accurate landfalls all around the world using this method, generally maintaining his latitude to within half a degree of the intended value , and any experienced navigation venturing deep into desert or out of sight of land before the coming of "modern" instruments like the sextant almost certainly relied on such techniques. So, it <span style="font-style: italic;">is </span>possible, but is it useful?<br /><br />Well, sometimes; today, people like myself who like to use the "road" less travelled have the benefit of tools like GPS (I recommend the excellent, cheap, tough <a href="https://buy.garmin.com/shop/shop.do?pID=6403">Garmin Etrex</a>); however, the very nature of independent travel in remote places means that equipment may well be lost, broken, or simply out-of-charge. By learning how to navigate <span style="font-style: italic;">without </span>any instruments which aren't permanent (I hope!) parts of my body, I'll be able to travel with a permanent built-in backup for the GPS and the compass (you'ld be surprised how many sailors run into GPS trouble). Apart from hypothetical equipment failures, navigation is a subject that I enjoy for its own sake; there is something deeply magical about looking up into the night sky, knowing the stars by ancient names from foreign tongues, and, <span style="font-style: italic;">simply by looking</span>, to find yourself.<br /><br /><span style="font-style: italic;"><span style="font-style: italic;"></span></span>Back to practicalities. At this latitude, the July sky isn't really dark at 23:00, so there weren't very many bodies to measure - simple identification was tricky, because only the very brightest bodies were visible. Even worse, not being at sea, I didn't have a clear horizon either. Nevertheless, I extended an arm and spread thumb and forefinger as far apart as they would go; for the average person, the span between thumb and forefinger will cover about 15 degrees<span style="font-style: italic;"></span> of sky. I levelled my arm at the invisible horizon, and began to measure.<br /><br />Waving my arm around the summer sky, I measured the altitude of a rising moon (itself covering only 0.5 degrees of sky, a useful checking-fact) at about 10 degrees and the bright orange of <a href="http://www08.wolframalpha.com/input/?i=arcturus">Arcturus (Alpha Bootes) </a>at about 38 degrees. I sighted <a href="http://www08.wolframalpha.com/input/?i=dubhe">Dubhe (part of the Plough Constellation</a>) too, although I forget the number; then, checked the observed altitudes against what <a href="http://mobilestarchart.sourceforge.net/">Mobile StarChart app</a> on my phone said they should be. I got the moon nearly dead-on - its real altitude being about 10.5 degrees - and Arcturus turned out to be just over 40 degrees above the horizon. The error for Dubhe was higher, about 3 degrees. <br /><br />For a first attempt, with no clear horizon, these measurements strike me as acceptable; if I had been using them to find my latitude, I would've had a pretty fair chance of finding my home country. Marvin Creamer did a lot better, though, so the next time I've got a clear horizon after dark, I'll give the procedure another try. In the meantime, I'm now wondering what simple instrument I might be able to construct to get those errors a little smaller. Ideally, these will be <span style="font-style: italic;">simple </span>instruments, such as a lost sailor on a small boat might plausibly fabricate. Also, wouldn't it be nice to measure latitude <span style="font-style: italic;">and </span>longitude? <br /><br /><span style="font-weight: bold; font-style: italic;">Coming soon...</span>Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-88277041425112247452009-06-23T08:54:00.000-07:002009-09-21T03:18:06.658-07:00Designing a new rudder, part 2<span style="font-style: italic;">By measuring photographs and doing a little maths, courtesy of the NACA 0012 formula, I was able to discover what size and shape my new rudder (transom-hung, constant foil cross section) should be. Next problem: what materials?</span><br /><br />My old rudder was a single piece, almost certainly a tropical hardwood, dense and strong. Marine plywood was an obvious option, except that no local suppliers had real marine-grade plywood (non-marine grade, which I have used for cabin furniture, can have voids and gaps within interior laminates, hidden weaknesses which could be fatal in a load-bearing structure). My old rudder was a single piece of tropical hardwood, which I also tried to source: a local supplier had lots of beautiful teak and iroko, but no planks wide enough to make a rudder in a single piece - they simply aren't there to be had (they've all been made into rudders already?). It might be just as well: a solid piece of timber can be sundered by a single stress-grown crack, not such a problem with laminates.<br /><br />Abandoning nature, I talked to the very helpful Liam Phelan of <a href="http://www.mid.ie/">mid.ie</a>, and began to investigate the possibility of a synthetic foam core (Corecell) wrapped in fibreglass. To get an accurate spec on which foam and how much glass, Liam suggested I talk to Martin Armstrong, chief technologist at <a href="http://www.gurit.com/">Gurit</a>, a firm which supplies composite materials to pretty much everybody who builds composite structures - submarines, wind farms, huge racing yachts, aircraft, etc. Martin is a busy guy, but he spent half an hour talking an amateur sailor and novice builder through the materials and techniques necessary to fabricate a composite rudder.<br /><br />First, the core: A550 foam (Corecell) for the rudder core; a single 8ft x 4ft x 25mm sheet would suffice. I wasn't sure how easy this would be to shape, but Martin reassured me that it is far less dense than wood, while also having no grain; normal wood working tools would suffice, it could even be sanded into shape; a surf form might be handy. Only one problem to watch: being an excellent insulator, it is really bad at dissipating heat, so power tools should have fresh, sharp blades to minimize friction.<br /><br /><div style="text-align: center;"><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-9Nmv2GGeIzCIwjXX_TRYT6BC1xuayRxEfIjuVos5IQ-lIErSAhnMOIshX4YXEUdOsnC_ny-gnCuhb-PWf5-zxKhJusvFR8mhimHIG8vVDmFdKS5q5DQcXSAwegqu94F7S9NPT8FIIP0/s1600-h/foil+and+fabric2.jpg"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 320px; height: 216px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-9Nmv2GGeIzCIwjXX_TRYT6BC1xuayRxEfIjuVos5IQ-lIErSAhnMOIshX4YXEUdOsnC_ny-gnCuhb-PWf5-zxKhJusvFR8mhimHIG8vVDmFdKS5q5DQcXSAwegqu94F7S9NPT8FIIP0/s320/foil+and+fabric2.jpg" alt="" id="BLOGGER_PHOTO_ID_5350815574196258114" border="0" /></a><span style="font-weight: bold;font-size:85%;" >Layers making up my composite rudder</span><br /></div><br /><br />Then, the exterior, from which will come much of the strength; Martin specified six layers of glass cloth:<br /><br />Layer 1: 290g 4-harness satin, laid at a 45 degree angle, and with a 100mm overlap both sides at the leading edge, and a similar tail at the trailing edge<br />Layer 2,3,4: uni-directional 500g fabric running top to bottom (no overlap)<br />Layer 5: 290g 4-harness satin, 45 degrees again<br />Layer 6: 290g 4-harness satin, 0 degrees<br /><br /><span style="font-weight: bold; font-style: italic;">This post is part of a series on making a fibreglass rudder with a foam core:</span><br /><a style="font-weight: bold; font-style: italic;" href="http://bluejotter.blogspot.com/2009/06/designing-new-rudder.html">Designing a rudder, part 1</a><br /><a href="http://bluejotter.blogspot.com/2009/06/designing-new-rudder-part-2.html"><span style="font-weight: bold; font-style: italic;">Designing a rudder, part 2</span></a><br /><a style="font-weight: bold; font-style: italic;" href="http://bluejotter.blogspot.com/2009/08/making-new-rudder-part-1.html">Making a rudder, part 1</a>Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-39718744666524202922009-06-16T06:41:00.000-07:002009-06-16T06:43:59.988-07:00Car cleaning tipOne of our cars has a light-grey plastic trim in the interior all around the ceiling. Looks nice and bright, but not so easy to keep clean. Today, we found the solution: all the black grubbiness around areas that hands touch a lot (e.g. the sunroof controls) was removed <span style="font-style: italic;">instantly</span> by the simple application of a popular brand of baby wipe. Looks good as new now. Excellent stuff.Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-82466334621900803542009-06-08T05:12:00.000-07:002009-06-08T06:10:58.975-07:00Astronavigation (Celestial Navigation) for BeginnersKnowing one's way around the night sky is a useful thing, if, like me, you have a telescope and want to know where to point it, or if, like me, you have ambitions to learn astronavigation. Until last week, sunset came early enough that I could get a few minutes of practice on every clear evening, standing in my garden and counting out the stars. This time of year, the orangey-red light <a href="http://en.wikipedia.org/wiki/Arcturus">Arcturus </a>is usually the first that I see; the distinctive <a href="http://en.wikipedia.org/wiki/Vega">blue blaze of Vega</a> is to the east, and when the sun's glow has faded a little more, <a href="http://en.wikipedia.org/wiki/Castor_and_Pollux">Pollux, Castor</a>, and<a href="http://en.wikipedia.org/wiki/Capella_%28star%29"> Capella (actually 4 stars, an exotic double-binary)</a> show up nicely.<br /><br />The stars that I am <span style="font-style: italic;">really </span>watching for, though, are <a href="http://en.wikipedia.org/wiki/Polaris">Polaris (the north star) </a>and <a href="http://en.wikipedia.org/wiki/Gamma_Draconis">Etamin</a>; obviously, Polaris is very useful, in that it gives a navigator a course to steer anywhere in the northern hemisphere above maybe 10 degrees of latitude (ish) - but why my interest in <a href="http://www64.wolframalpha.com/input/?i=etamin">Etamin</a> (gamma <a href="http://en.wikipedia.org/wiki/Draco_%28constellation%29">Draconis</a>)? Well, it so happens that my home port on the eastern seaboard of the north Atlantic is just a smidgen north of Etamin's declination (celestial latitude), which is 51 degrees, 29 minutes, 20 seconds. Now, Polaris has the useful feature of <span style="font-style: italic;">always</span> (where always = "several hundred lifetimes") being 51 degrees and X minutes above my local horizon; Etamin, by contrast, whirls around the sky, never dipping below the horizon, but once per day passing through the <a href="http://en.wikipedia.org/wiki/Zenith">zenith</a> - what you might call "Etamin-noon".<br /><br />In practical terms, this means that were I some day to be lost in the blue vastness of the North Atlantic, no GPS, compass, sextant or chrometer to guide me home, I could use Etamin to find the latitude of home, sailing north if Etamin passed north-of-zenith, and sailing south if it passed south-of-zenith. Once at the right latitude, I would need only to keep an easterly course, and a sharp look-out for pointy rocks. Of course, measuring the fixed, non-whirling altitude of Polaris is more convenient - it can be done whenever Polaris is visible - but that would require an instrument,<a href="http://en.wikipedia.org/wiki/Sextant"> ideally a sextant</a>. <a href="http://en.wikipedia.org/wiki/Marvin_Creamer">Marvin Creamer</a>, an American amateur sailor and retired professor of Geography, <a href="http://www.globestar.org/">once sailed around the world on </a><span style="font-style: italic;"><a href="http://www.globestar.org/">Globestar</a> </span>using techniques like this and <span style="font-style: italic;">no instruments whatsoever</span>, making surprisingly accurate landfalls.<br /><br />Unfortunately, during part of the year, Etamin-noon would fall during daylight hours - but even then, other bright stars at similar latitudes could give useful hints. Which bright stars pass directly over your home port / next port? Just follow the <a href="http://www33.wolframalpha.com/input/?i=brightest+stars+declination">linked query at Wolfram Alpha</a> to see a table listing the hundred brightest stars by declination, and you'll soon be on your way. A useful tool to help you practice is the (totally free) <a href="http://mobilestarchart.sourceforge.net/">Mobile StarChart</a>, a java applet you can install on your mobile phone - it only has about thirty star names, but is open source, so you could add more.<br /><br />Living a long way from the sea? Astronavigation can also be pretty useful in the desert, and was much practiced<a href="http://en.wikipedia.org/wiki/Vladimir_Peniakoff"> by people like Popski.</a> Must learn how to use a sun-compass one of these days.Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-1177885529446997302009-06-06T09:32:00.000-07:002009-09-21T03:17:41.675-07:00Designing a new rudderSo, our beloved <span style="font-style: italic;">Briongloid</span>, a 6.6M fin-keeled sailing yacht went adrift from her mooring, and spent an uncomfortable day bouncing on pointy rocks. The pounding reduced her wooden rudder to matchwood - so it's time to make a new one.<br /><br />How big, and what shape? From a profile scale illustration of<a href="http://yachtarabella.blogspot.com/2005/08/about-pandora-international.html"> a Pandora International</a> (our boat's model) I figured out the height and width - about 1.65 metres * 0.37 metres. Now, I just needed the cross-section's shape.<br /><br />It turns out that the <a href="http://www.vacantisw.com/foildesign.htm">best shape for a rudder is a foil </a>- like the shape of a bird or aircraft wing, the magic of the foil shape is that it generates lift (unlike, say, a flat surface, which only creates drag). Back in the 1930's, the boffins at <a href="http://en.wikipedia.org/wiki/NACA">NACA, the forerunner of NASA</a>, investigated different foil types to find the best shapes for different aeronautical (and incidentally marine) applications.<br /><br /><img src="http://spreadsheets.google.com/pub?key=rIK7ordWunz3juVJa-RRzSw&oid=1&output=image" /><br /><br />For relatively slow-moving displacement craft like our yacht, their<a href="http://www59.wolframalpha.com/input/?i=naca+0012"> "NACA 0012" foil</a> is the best fit; by creating a Google Calc document based on the <a href="http://wapedia.mobi/en/NACA_airfoil#1.">NACA 0012 formula</a>, I generated the cross-section above (y and x axes are not in proportion). Note the very round leading edge and thin trailing end.<br /><br />Many fins and rudders taper from one end to the other, and give the leading edge a crescent profile; this tapering reduces drag by about 4% - for me, not worth the much-increased difficulty of shaping the foil.<br /><br /><span style="font-weight: bold; font-style: italic;">This post is part of a series on making a fibreglass rudder with a foam core:</span><br /><a style="font-weight: bold; font-style: italic;" href="http://bluejotter.blogspot.com/2009/06/designing-new-rudder.html">Designing a rudder, part 1</a><br /><a href="http://bluejotter.blogspot.com/2009/06/designing-new-rudder-part-2.html"><span style="font-weight: bold; font-style: italic;">Designing a rudder, part 2</span></a><br /><a style="font-weight: bold; font-style: italic;" href="http://bluejotter.blogspot.com/2009/08/making-new-rudder-part-1.html">Making a rudder, part 1</a>Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-34709951495485050812009-04-07T11:46:00.000-07:002009-04-07T14:01:49.155-07:00Review: Imray Chart Plotter (ID30)In the current economic climate, the demand for my services has decreased; so, less cash. Luckily, this <span style="font-style: italic;">also</span> means more time for sailing. I'm planning a little cruise westward, which (winds permitting - hah!) will take me off the edge of my chart folio. To help my planning, I bought my first digital charts and charting software, Imray ID30, covering the west coast of England, Scotland and Wales, and the whole of Ireland. Usefully cheaper than their Admiralty equivalent (and discounted further for this Euro purchaser by the weakness of Sterling), the CD arrived promptly from those nice people at <a href="http://www.chartsales.co.uk/">Marine Chart Services</a>.<br /><br />On first running the software, users need to register; the first step involves giving an address that <span style="font-style: italic;">must </span>include a postcode. The tiny country I live in doesn't have those anywhere outside the capital, and even then, they aren't in the UK format which this officious little dialog demanded. After some trial and error, I discovered that "--- --" was an acceptable location(!).<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgTXcFCxOJz1xLzsLQOZEFnZy0kBOC_SXL7nQCaFJBB8YzpKb94jgdcff73wA7pg3X5dl0sFFdFXVI0hGwMrd-9z3OAwJMW1KiqVeZvjjU9ErcGbSpOD3h8mH2G2Rj5stiC-Aeu33t9hIY/s1600-h/dividers.JPG"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer; width: 257px; height: 200px;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgTXcFCxOJz1xLzsLQOZEFnZy0kBOC_SXL7nQCaFJBB8YzpKb94jgdcff73wA7pg3X5dl0sFFdFXVI0hGwMrd-9z3OAwJMW1KiqVeZvjjU9ErcGbSpOD3h8mH2G2Rj5stiC-Aeu33t9hIY/s320/dividers.JPG" alt="" id="BLOGGER_PHOTO_ID_5322030357955785426" border="0" /></a><br /><div style="text-align: center;"><img src="file:///C:/DOCUME%7E1/Ed/LOCALS%7E1/Temp/moz-screenshot.jpg" alt="" /><span style="font-size:85%;"><span style="font-weight: bold;">Lovely coordinates, but what's the distance?</span></span><br /></div><br />My first impressions of using the actual chart plotting software itself are that opportunities have been missed - for example, a simple tool like dividers doesn't work quite as well as it could. In the above example, I'm trying to measure the width of the anchorage at Port Magee (on Ireland's lovely south west coast). Ideally, the measurement text box would come out from its hiding place - an easy fix could be "borrowed" from CAD tools and their dimensioning widgets.<br /><br />A bigger problem is (how ironic!) navigation - moving across a chart takes ages, not because the software is slow (it isn't), but because charts are often many screens wide. A zoomed-out overview in a small overlay window to show the wider context of the currently visible portion of chart would be a nice addition. <br /><br />My biggest beef, however, is with chart selection. Although the "default" chart covers the full range of the folio, selecting detailed charts for harbours and so on requires browsing a list which identifies them by codes and place names. I understand the reason for this; it is the easiest way to move paper charts to a digital platform. However, it does little for usability, and isn't likely to find favour with users who are familiar with modern digital mapping, as implemented by the likes of <a href="http://maps.google.com/">Google Maps,</a> Map 24, etc. Why <span style="font-style: italic;">can't </span>I go from a whole-Ireland view to a close-up of the Cork Harbour chart in one click?<br /><br />Enough with the negatives; the charts themselves look good, and I got a lot of mileage for my money - the sheer amount of data that must be collected to make these charts is astonishing. I'm already looking forward to plotting my next cruise (and with departure mere weeks away, it's not before time!).<br /><br />Favourite feature so far? Definitely the print option - beautiful, instant reproductions of charts or sections of charts are only a click away (after you accept the "not for navigation" license agreement message).<br /><br />The verdict so far: excellent value for money. The software is spare, but very functional, and the coverage is great, and I'm very glad I bought it.Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-28135823930217540572009-02-26T05:25:00.000-08:002009-02-26T06:00:09.132-08:00Cleaning a microwave ovenThe levels of dried-out burnt-on food on the roof of our microwave oven were well below bachelor-tolerance levels, and, considering the dose of radiation they had received, either totally sterile or already in possession of super powers. However, with my wife due back the next day, a <a href="http://en.wikipedia.org/wiki/Fab_(semiconductors)">fab-like </a>level of cleanliness was highly desirable...<br /><br />The first attack (dish-scrubber) was easily repulsed; the fossilized remnants of dinners past appeared to have attained an inter-molecular level of integration with the substrate. Doubled the elbow-grease factor, tried again, same result. Next, considered the array of chisels, lump-hammers, power saws, angle-grinders available to me, but rejected them on grounds of safety (mine, on the return of She Who Must be Obeyed). What to do?<br /><br />Then, the light bulb moment. I got a bowl full of water (just water), deployed it to the centre of the oven, and gave it 8 minutes at 800 watts. Opened the door again to a steam-blasted oven that came clean on the first wipe. <span style="font-style:italic;">Result!</span>.Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-66581319714811136832009-01-06T08:33:00.000-08:002009-01-06T09:28:04.173-08:00CPU HogSo there I was, tapping away at quotidian tasks, when I noticed my PC was responding with all the dash and verve of a fossilized member of <b><a href="http://en.wikipedia.org/wiki/Tortoise">Testudinidae</a>. </b>A quick glance at Task Manager showed that GoogleDesktop.exe was the CPU hog - apparently, it required 99% of CPU to index the work I was doing with the other 1%. Surely that couldn't be right? <br /><br />Well, I love the speed and power of Google's Desktop search, so I didn't like to just kill the offending process. To get me a little extra responsiveness from my PC while I searched for a better fix, I using Task Manager to give the <span style="font-weight: bold;">GoogleDesktop.exe</span> process a lower priority. To find the real problem, I would need more data on what <span style="font-weight: bold;">GoogleDestktop.exe</span> was trying to do - so I installed the impressively capable and friendly <a href="http://technet.microsoft.com/sv-se/sysinternals/bb896645%28en-us%29.aspx">Process Monitor</a> (a free trouble-shooting tool from Microsoft).<br /><br />This tool gives details on the interactions of running processes with the operating system, and updates in realtime. For example, I could see GoogleDesktop opening new files and folders to index them even as I created them. What was interesting was that <span style="font-weight: bold;">GoogleDesktop.exe</span> was also repeatedly accessing a file called <span style="font-weight: bold;">hes.evt</span>, even when there was nothing new to index. I deleted this file, and an instate later, a new <span style="font-weight: bold;">hes.evt </span>appeared (at first I thought it hadn't been deleted, but the new one was tiny and had an up-to-the-second creation date).<br /><br />And now... CPU usage fell away to "idle" levels, and Google Desktop Search still works. Great result, but what was the underlying problem? No idea whatsoever.Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0tag:blogger.com,1999:blog-8260279385614994872.post-54465135796862995132008-12-16T02:48:00.000-08:002008-12-16T05:11:45.475-08:00Finding dolphins and whalesI've covered quite a few kilometres looking for whales and dolphins, and I have decided that I am doing it wrong. The sea is very, very big, and from my deck I can scan only a very limited area. Even worse, the animals that I am trying to find spend much of their time submerged - I should be looking <span style="font-style: italic;">under</span> the water, not over.<br /><br />I've heard whales and dolphins on hydrophones before, and it was possible to get a sense of range simply from the volume. You can hear them a long way off, too - loud animals, and sound carries very well through water. What I think was missing from the experience was stereo - with stereo, it should be possible to estimate the direction from which the sounds are coming - and so steer closer. <br /><br />What I would like to do is to trail two hydrophones astern of <span style="font-style: italic;">Briongloid</span> and hook them up to a pair of stereo headphones. Now, sound travels much more quickly through water than through air, which might make it hard for the brain to process the data fast enough - but a simple fix for that would be to increase the spacing between the hydrophones so that the time sound takes to get from one to the other in water matches the time sound takes to get between human ears in air. <br /><br />Since <span style="font-style: italic;">Briongloid </span>is usually powered by sail (rather than a noisy engine), I imagine it would be possible to trail my pair of hydrophones throughout a voyage, monitoring constantly for cetacean activity. Interesting idea: now how do I actually go about building such a thing?Phibiushttp://www.blogger.com/profile/13608110955562088043noreply@blogger.com0