On the first leg video I used Makeblock 37mm 12 volt DC motors bought at Radio Shack
 when the stores closed. The gear motors were 12v with 4.5 Kg-cm rated torque, 
50 rpms. They were hooked to a Parallax DHB-10 motor driver board.  The newest 
leg video I changed the motors to Actobotics 116 rpm @12 volts from Servo City. 
Rated torque 11.5 Kg-cm., 100 rpms.  These motor are faster, have more power, 
and have encoders.  The Parallax motor driver board I used supports encoders.  
The black parts are printed in Matter-hackers nylonX at 30% fill and the 
“part knee_below3” is what separated in two places. It needs to be lot stronger 
as that was only 2000g or 4.4 pounds.

(2) leg testing - YouTube


5 years 3 months ago

Interesting,  I suspect the part split along the layer lines of the print.  I wonder if adding some screws that run from the top/bottom of the part would hold it together better.

my guess is the layer adhesion isn't what it needs to be here.  I have heard of some people using a heated chamber after the part is finished to help "cook" the parts to make them stronger.

either way,  all very exciting.. the mechanism seems to be working quite well  (aside from some sheer stress issues.)

keep it up!  love to see the progress!