I have taken some photos of my new version of my "limb embiggener" where I've uses bolts instead of fabric tape for the joints.
It still seems much easier then the original skeletonics system that inspired me, and more sturdy than my previous mechanical arm. Hopefully there's enough information to give anyone a good start to making one.
The Perth Artifactory had all the tools I needed - drill press, saw, clamps, measuring tape.
I bought some more bamboo and some long bolts, I think 3/8 inch diameter as the metric ones at Bunnings seemed either too wide or too short, cut some bamboo, drilled the holes in the bamboo, big enough for the bolts to go through either easily or with a push, and fit it all together.
Taped on the bicycle brake from the previous arm, originally from a local bike shop, to be the claw.
The holes through the bamboo were sometimes visibly misaligned, so when I laid the bamboo down with one hole vertical, the other was off vertical. I may have had to widen a hole now and then to give it enough slack to cope with the misalignment, and but generally it seemed remarkably tolerant of my errors.
To wear it, I strap it onto my arm with double-sided velcro - the stuff with hooks on one side and loops on the other.
All my mechanical arm pictures on flickr:
Tensegrity: one of the principles I used in designing it - each length of bamboo should be under compression or tension only, it should not be under significant bending stress. Where it was, I reinforced it with pieces to take the load as compression and tension instead. That's basically how I added the triangles.
There is still a bit more reinforcement that could be done, but it would just help take the weight of parts of the arm, not whatever load is held with the claw.
Some of the bolts stick out a fair bit, so I have to be careful not to scratch things or myself with them by accident.
This entry was originally posted at http://caspian-maclean.dreamwidth.org/58