After a bit of head-scratching I decided simple was best, and rather than cut and fold these with a single layer I just joined two of them back-to-back. I accidentally dropped the first one on the kitchen floor while I was making them, and it bounced, so I stomped it and kicked it around some with my boots on. No visible difference in appearance even, that will do nicely.

To get the material flat like that, I heated it in an oven for a few minutes at Gas Mark 5 with the door open for observation. Quite how pre-formed sheet handles remains to be seen, but after a few minutes it had turned to a silicone-like texture, the ends of the tube belled slightly and it shrank by about 5mm over 100mm lengthways. There was no visible change in diameter, and all I did was open the tube and flatten it under a bit of wood to form it into sheet.

I also too the blowtorch to the spine as I managed to get the curve in that off-centre. I bought this tube in 3m lengths presumably from a giant roll originally, they are all curved as a result. Shorter lengths and bigger sizes dont have this problem.

True to form, Doc commented that there are always lengths of this lining the streets in skips. As a free working material its hard to beat for sure, thanks for pointing that out my friend. :-D

The frame has worked out to be 12in long without the head, slightly larger than I'd anticipated mentally, and with the head will be bulkier than a cat but similarly sized.

Those are the fore-legs. I've run out of screws for now, the rest of the frame is dead tube as the back legs dont have knees, and the neck is a gimbal that screws to the tube at the front.

The fore-legs will be attached so that the servos are canted in at 45 degrees. This is so that both front paws can touch the face. This is also so that Cub can make a stable triangle to walk on, echoed in the back legs and tail, so that Cub can hopefully sit up without falling backwards.

Cardware's sensor system was a PITA trying to route cables from foils through complicated structures. Cub has a cloth shell to provide form, with the sensor wire array sewn directly to it, and a furry washable skin that zips around it for styling.

I'll get to work on this as soon as the frame is complete and I know the exact size of the skeleton.