Well, it is official. I purchased all the parts I didn't already have. I am matching what Dannydefe ordered so we can closely collaborate. He has some equipment that I don't have so I expect to see some cool composite bot from him. I on the other hand am going with PVC pressure columns.
I am handing my drawings over to my students. They are going to do revise, print, and mill the necessary parts. I am also going to have them log the whole build. I am still deciding on what is a realistic level of documentation I can ask of them. They are all very talented and gifted but they have what I consider more than a full-time college load. (This is a residential high school for gifted students.)
***WARNING: I AM ABOUT TO BRAG ON MY KIDS.***
If you guys think I am crazy for giving this project to high school students who only have 3 weeks to complete the project then check out this awesome cardboard robot. They decided on their own to restrict the arm to cardboard as a fun design challenge. The cardboard robot was designed and built in 6 weeks while I essentially ignored them and did work on Simpson and Wally. :-) (That is actually underselling it. They built a prototype with a jigsaw over a 3 week period. Redesigned it. Laser cut that version. Found more problems. Completely rebuilt the robot again from the ground up in a few day.)
I walked them through the inverse kinematics. I explained that you essentially just have to find the z value of the top intersection of a circle (with the radius of the arm) with a vertical line that is the length of the arm's xy projection away from the center of the circle. Instead of saying "huh" these guys immediately point out that we also have to account for the rotation/translation coupling of the arm.
I am handing my drawings over to my students. They are going to do revise, print, and mill the necessary parts. I am also going to have them log the whole build. I am still deciding on what is a realistic level of documentation I can ask of them. They are all very talented and gifted but they have what I consider more than a full-time college load. (This is a residential high school for gifted students.)
***WARNING: I AM ABOUT TO BRAG ON MY KIDS.***
If you guys think I am crazy for giving this project to high school students who only have 3 weeks to complete the project then check out this awesome cardboard robot. They decided on their own to restrict the arm to cardboard as a fun design challenge. The cardboard robot was designed and built in 6 weeks while I essentially ignored them and did work on Simpson and Wally. :-) (That is actually underselling it. They built a prototype with a jigsaw over a 3 week period. Redesigned it. Laser cut that version. Found more problems. Completely rebuilt the robot again from the ground up in a few day.)
I walked them through the inverse kinematics. I explained that you essentially just have to find the z value of the top intersection of a circle (with the radius of the arm) with a vertical line that is the length of the arm's xy projection away from the center of the circle. Instead of saying "huh" these guys immediately point out that we also have to account for the rotation/translation coupling of the arm.