andypugh

I think that it should be possible to make the claws open and close (controlled by toggle switches on top of the hand grips) using 3D printer parts (which are cheap and readily available now). Small NEMA 17 stepper motors, Pololu stepstick drivers, an Arduino to generate the step pulses and drawer slides for the claws to move on. I wrote a more detailed description with eBay links, but then realised I was logged in through my work account by mistake and deleted it. If you are interested in this idea I am happy to spend some time on a more detailed design. It would, of course, add weight and you would need to carry more batteries. (batteries in the stilts might be a good solution, then you are not carrying the weight except when walking).

It's a circle cutter, they are a fairly standard tool. here is a commercially made one on eBay: https://www.ebay.co.uk/itm/263851268929You might have to perform a more local search to find one near you. I think you could improvise something very similar using one of the cheap disc shears: https://www.amazon.com/KAKA-Industrial-MMS-1-Manua...A length of wood against the ceiling might suffice to hold the metal down on to the pivot. (to suggest one way to avoid building a large stiff clamp frame)

An alternative to sooting the surface of aluminium to judge temperature is to scribble over the surface with a marker pen (I used a green OHP pen) and then heat the metal until the colour disappears: This is the approach I used to make some aluminium headlights:http://bodgesoc.blogspot.com/2015/02/headlights.html(Possibly I could publish that as an instructable?)

I got some from https://www.ebay.co.uk/itm/123147701780

Well. Many thanks for your votes everyone, but it seems that I didn't make the list of finalists. I won't pretend that I am not disappointed, I was really pleased with the result. I can only conclude that the quality of the instructions did not make the grade.

Yes, a string of COB LEDs under a layer of yellow goop. I see some evidence for a flexible version, but these were rigid and easily broken. In fact about half of the first set arrived broken. (I was given a partial refund.)

I did mention the "lazy filament" in the description. I have not yet worked out the source of the problem. It does glow, just less brightly. (I haven't worked out the cause because I haven't really looked, as soon as this was published I was straight on to other things that had been pushed in to the background by it)

Looks great, and the potential electric shock when fumbling with it in the dark can only add to the effectiveness at waking you up.You asked about free schematic packages. For Arduino projects it is probably worth looking at Fritzing. However I use KiCAD. Creating new components in both packages is a bit painful. But then I have tried many PCB design tools and creating new components is always painful.

As an alternative to epoxy look at pattern-coat. http://www.easycomposites.co.uk/#!/patterns-moulds...It is a 2-part polyester resin. It goes on like paint, but unlike paint it does not shrink as it hardens. You can add pigments for a one-step smooth-and-colour. I have used it on 3D-printed foundry patterns. This photo isn't the best example of what is possible, as I was aiming purely for function, and this is the pattern _after_ it came back from the iron foundry. https://photos.app.goo.gl/zhAI9el2wYjacGZk2

Assuming that the car has a vacuum brake servo the simple answer there might be to get an electric vacuum pump from a production car. Diesel cars do not make vacuum naturally, but they still tend to use vacuum brake servos. They have normally used a dedicated vacuum pump driven from the end of a camshaft. These would not be much help, but in the search for better fuel economy some cars are now starting to have an electric on-demand brake vacuum pump. You will probably have to look in Europe to find one, though.