After fully assembling the Robo-Barista I nearly have the software ready to run all 5 axes in coordinated moves. Unfortunately shortly after this video was taken I entered a move of 1000 when I meant to hit 10 on the shoulder axis and sent it flying off the table. It broke the hand upper plate and the base (the largest part which that big gear is slotted in to), and ripped out all the wires. I had it kind of poorly supported since the motor on the turn table sticks down further than the turn table, so in lieu of a proper bolt down base I had it temporarily sitting on a roll of masking tape. Only slightly deterred I epoxied the broken parts back together and rewired it.
The new elbow is actually the original elbow. That is, I had planned to use this linear screw with 5 leads and 1.25 in/rev from the start, but deciding it would be too weak I switched to a rod with 20 threads per inch. It turned out the motor was stronger and slower than I originally planned, and a nice fast lead screw was ideal. So I made this new coupling which has a spline to lock on the pinion already mounted on the motor on one end, and a slightly tighter copy of the threaded I made for my lead nut.
By the way, I 3D printed a lead nut by measuring the screw, and after testing and adjusting it twice just printing short segments, I got it working pretty well, so that's kind of cool. I'm going to try a set that makes an anti-backlash pair soon.
So I had the robot back together, all motors in and wired ready to put the finishing touches on the program just in time for another update before the contest ends. But long story short I'm on top of a mountain in Nevada and I'll only be back this weekend before going to Minnesota. No one died, it's just work trips.
For now, a video of the arm in motion with the new 5 start lead screw. Also note that the hand motor is in place. If I knew the robot was about to be smashed to pieces I'd have taken more video of it, but this is what I had on my phone to post. Everything is installed. I have 2 days at home this weekend before the contest ends and the robot is fully assembled. It looks like in the video below except for some epoxy and a new pulley on the wrist motor. It's so close, I'm going to try to get it done this weekend while I'm home.
As always, if you like the project, please vote for me here (Paul Sisneros - Auto Barista):