Reviving an old laptop: Puppy Linux

We 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 second laptop handy for some really essential web-browsing, we couldn't bear the eons-long boot-time and the extremely sluggish browsing experience that followed.

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 too slow for me? 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 scary: an OS that was fast and stable, sure, but only for those who enjoy knitting their own device drivers of a winter's evening.

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 Puppy Linux - 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 was able to boot into Puppy Linux straight from the CD without even installing it! 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!

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).

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 and have it launch instantly - whereas Windows, in my experience, shows you the desktop as a placatory measure, while it continues frantically to load things in the background.

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.

Printing in 3D with Shapeways: a review

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!

One ring to bind them...

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 NURBS modeller MOI (Moment Of Inspiration). 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 Shapeways operating in the Netherlands. The same company offer a variety of other materials, including several plastics and glass. They also offer some lovely metal finishes 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.

So, how did it turn out?

The good: 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 (this ring) turned up well within their specified timeframe.

The not-so-good: 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 fattura, the Italian term for the imperfections that reveal how a thing was made.

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.

Sugru: almost too much fun

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.

Sugru in action

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 Sugru.com . 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.

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.

Making a rudder, part 4: designing gudgeons

With my rudder blade is almost ready for the water, so time to think about it can connect to the boat. To hang it from Briongloid's 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?

Figure 1: Gudgeons (yellow) allow a transom-hung rudder (blue) to pivot about a vertical axis (red)

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: carbon fibre (weight for weight, the median sample of carbon fibre has six times the tensile strength of stainless steel [Source: Wolfram Alpha]. 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.

So much for strength: what about friction? This is a moving 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 on the excellent blog of a Canadian who is building "Raven", a nippy trimaran from Ian Farrier's F22 design. 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.

Figure 2: Gudgeon cores (carbon fibre ties not pictures)

Figure 2 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.

Coming in the next post: making and mounting the gudgeons

Previous posts in the series:
Designing a rudder, part 1
Designing a rudder, part 2
Making a rudder, part 1

Making a rudder, part 2
Making a rudder, part 3

Taking the long way around

In which no rudders are mended, but some beautiful footage is watched.

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 Dylan Winters circumnavigating Britain, very slowly in "the slug", a Mirror Offshore (19 feet, with inboard diesel, designed by Van de Stadt, the same man who designed my own poor Briongloid).

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 Beaumont Quay (up a canal dug by slaves in Roman times). Along the way, he takes beautiful HD footage of boats large and small - lately, gorgeous Thames barges have been a recurring them.

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 Cities of Foam.

Enough talking; if you take even a passing interest in things boaty or the British coastline, do yourself a favour and wander over to Keep Turning Left. Well worth the price of admission.

Making a new rudder, part 3

Designing a rudder, part 1
Designing a rudder, part 2
Making a rudder, part 1

Making a rudder, part 2

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.

From Laminating new rudder

Hardwood inserts epoxied in place, ready to take bolts

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.

From Laminating new rudder

Rudder core, fully shaped, smoothed, faired, and ready for lay-up

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.

From Laminating new rudder

Unidirectional glass fabric, 500g/square metre

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).

From Laminating new rudder

Ready for Fun with Chemicals

From Laminating new rudder

Wet fabric (transparent) draped over the rudder core

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).

Miscellaneous tips:

• Clean your squeegee straight after use, while the resin is still soft
• 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).
• Disposable nitrile gloves give great tactile feedback - actually better than the heavy kind (plus, no clean-up). Very, very cheap at B&Q - and insanely cheap on E-bay.
• It is much easier to use too much resin than too little
• ...but you still need to keep an eagle eye for dry spots.
• take your time and do careful work - resin sets fast, but not crazy fast
• use peel ply - leaves a lovely smooth easy-to-work with surface, helps remove excess resin, well worth the money
• an ounce of preparation (masking tape, polyethylene sheets, etc.) saves a ton of fixing up later

Toys

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.

Version 1: Sled with upright handle

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 inside the sled, and tried to pull it over his own toes.

Version 2: platform to stand on, double-ended

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.

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.

Version 3: build-in rocking function!

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.

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).

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 his fun.

Dads, Mums, Aunties and Uncles: to your sheds! Go build!