I have recently been working on a second biped. The first one I built was the BRAT but I had always wanted to try the larger version. I have custom machined the head and I am also working on making simple hands using as much as the SES parts as I can. I custom machined the palm part of the hand with SES bolt pattern to mount to an ASB-18. I ordered more parts to finish the design and will post pictures when Done. I have a rough walking sequence already but I need to wait till I have the arms done before I get to deep with the SEQ stuff. The 475 servos for my ankles are proving to be to weak. They can get the job done but barley. I’m guessing once I get the amrs mounted it will makes things worse. I might have to get 645’s for the ankles and hips.
Got more parts in for the hands. I still need to machine aluminum fingertips, and a clamp piece for the tendons. The tendons are simple zip ties. Not sure if the micro servo is going to have the power to pull all the fingers. I may have to use fishing line if it fails. Here are some pictures of what I have so far. Sorry the photos are not as sharp as they could be. I didnt want to bother with getting a tripod.
That’s right! Igus hands! I had the idea for the longest time. One of the machines I programed at work uses larger ones and that’s where I came up with the idea. I looked around online for the smallest ones and these are it. I noticed Andrew Alter over at trossen did something similar, so he beat me to it. My goal was to try to make my hands using SES parts as much as possible. The servo actuator for the fingers idea was inspired by an online posting about “Melisa hands”. It’s been fun to make.
I tried running 4 of the 5 fingers using the zip ties and it barley worked. Sometimes it would just close the fingers, most of the times not. The micro servo just is to weak. The servo also got very hot. I bought some 50 pound fishing line and there was a 50% improvement of the amount of effort it takes to close the fingers. This will work with the micro servo no problem and better yet, it will be able to move all 5 fingers. I need to machine a mounting plate for the C bracket so I can attach all the lines. I also removed one link for the thumb and it looks like a thumb and not a fifth finger now.
I wish I could add an elbow to the arm but it’s hard to keep the length down. Got any ideas innerbreed?
I appreciate it!