CM6 - Compliant 3D printed robotic arm

Description

The goal of CM6 is to be a go-to robotic arm framework for people interested in robotics. CM6 uses 6 gimbal BLDC motors paired with small gear ratio gearboxes ( from 1:5 to 1:9), by doing that it is passively compliant and safe. Each Joint is using an S-Drive BLDC driver that is mounted on modular actuator designs for specific gimbal motors. Design can be changed easily by using different size aluminum extrusions or changing the gear ratio of modular gearboxes.

The total price of this first version is around 1000 dollars in raw materials. But I believe that the future version could be pushed to around 700-800 dollars.

Project Logs

Collapse logs

Total assembly!
Petar Crnjak • 2 days ago • 0 comments

I finally assembled the arm! It is looking really promising but everything will be revealed when I start some hardcore testing! Here are some pictures :D
Assembled base (Joint 1 and 2)
Petar Crnjak • 3 days ago • 0 comments

Assembled the last parts of the robot. Now the only thing left is to put it all together and start testing and playing around with it. Joint 1 these pictures is using 8:1 planetary gear reduction and joint 2 is also using 8:1 planetary reduction.
Upper arm + forearm
Petar Crnjak • 4 days ago • 0 comments

So this is assembled forearm and upper arm. So upper arm is using aluminum extrusion to connect joint 3 with joint 4. By using aluminum extrusion we can lengthen and shorten the arm and change the reduction ratio of joint 3 by changing a few parts. The length of extrusion in this picture is 200mm. Gear reduction of joint3 is 8:1 planetary gear ratio and then 32:28 belt reduction. The total reduction of joint3 is 9.14285:1.
Forearm assembled
Petar Crnjak • 5 days ago • 0 comments

So this is a complete forearm assembly. It is still looking pretty clean because there are no wires but once it is wired up wires will be visible.
Joint 6 is 5:1 planetary reducer. Joint 5 is plantery 6:1 and join 4 is 6.5: 1 bevel gear + HTD M5 belt.
as you can see here joint 5 is using a 2:1 bevel gear reduction and after that 3:1 belt reduction. Total reduction is then 6:1.
Gallery of robot renders
Petar Crnjak • 6 days ago • 0 comments