Robot Arm

Devlog #3

So now i have printed all the parts and assembled the arm up to the wrist, but a few problems prevented the arm from moving properly.

• The gears at the elbow are slipping when under load and also the shafts supporting them are not stable.

I think I can fix this by locking the two shafts together and using wider M2 gears.

• The belt at the shoulder is also slipping under load.

I think that i just need the gears to be bigger so that they can tension the belt better.

• The elbow joint servo doesnt have enough movement to drive the whole elbow 180 degrees because of the gears.

I messed up this part because i was supposed to buy the 270 degree servo not the 180 one. Ill be waiting for the 270 servo to arrive.

Aside from those problems I have written code so that I can control the servos by angle and not PWM pulses.

The base of the arm works fine, Ill be controlling that as soon as i learn how to control a stepper motor.

For now I have redesigned most of the arm to fix these problems, but as i wait for the servo and all the parts to print, ill try to work on a web that can control the arm.

Devlog #2

Finished printing everything and started testing if everything fit together. Some of the components had weak spots or didn’t fit together well.

I had to go back and forth between CAD and printing for a while because my tolerances weren’t quite correct. Everything fits nicely now.

I also made a GitHub repo and added all the CAD files, BOM, pictures etc. I will update GitHub frequently, and everything needed to recreate this project will be there.

I also made a wiring diagram and in the process realized that I needed a few more components to make sure that the arm would work smoothly and safely.

I was kinda hard to learn why I needed all these different components but in the end I think it makes sense to me now.

The next steps now is probably to buy the components and then assemble the robot.

In the meantime though I think I can start writing some code on Inverse Kinematics for the Robot. I want it to be able to move all the servos to the correct angle when given some coordinates.

Devlog #1

Completed the CAD assembly for my robot arm. I plan it to be a 5-DOF arm with 5 motors for movement and 1 motor for the claw.

I’m using 5 servos and 1 stepper motor right now but I don’t know if I should change it all into servos.

I also made the arm be able to swap grippers pretty easily.

Im gonna print everything for this arm, gears, gripper, etc. I can also 3d print the ball bearings but I think its better to buy them.

The next step is to start printing everything, buying all the parts and start assembling it. Once Im done assembling Ill start coding it.

I plan for the arm to run on a Raspberry Pi and be controlled via an app.