Building a 5DOF robot arm 3

Here’s the latest on the 5DOF arm.

Tomorrow I’m preparing the last Makelangelo kits that will ship before the Vancouver Mini Maker Faire. I spent the better part of the day connecting the forearm to the bicep based on yesterday’s design. My design software crashed and corrupted a few files. Boo! I also experimented with limit switch positioning. I think the two opposite sides of the wrist are best – I can catch three different kinds of dangerous movement with only two switches. Plus the wires all run the same length, which makes them easy to measure and bundle together. The next time I rebuild the arm I’ll have specially placed holes for flawless switching.

Am I starting to experience diminishing returns? The tiniest change can have a trickle down that affects 4 or 5 laser cut parts. I’m resisting the urge to scratch at parts of the design that “itch” but still work. I tell myself they’ll get better soon enough. Keep your eye on the prize.

I can see how the shoulder and the base should look in my mind’s eye. Just like the switches it will take a few iterations to work out the details. I’m a little excited by the idea that I might not have enough power to lift the arm. What if I have to print a whole gearbox? Can I do it? How long would it take? It seems like a judicious combination of bearings and gears, both of which I’m learning about quite a lot these days. Heh – I thought these were good minecraft blocks, but it turns out maybe I can put them together to make an even better block.