Pico MMU Winch

Winch Drive

CAD: Online CAD Viewer

First, please look at the CAD model and try to understand its functioning mechanism.

1. Cut two 25cm strings
2. Tie each thread to the CAM pulley and to the servo pulleys.
   • On each pulley, thread the string though the holes, from inside to outside and then back inside
   • Tie three or four normal knots and cut the excess string

3. Loop the wires over the CAM pulley as shown in the CAD assembly
4. Close both sides of the assembly (side arms with bearing holes) and make sure the strings are looped the right way
5. Install the printed CAM alignment guide that sets the 0 position
6. Power on the servo (printer) and set the angle to 0 (it is usually 0 when it receives power)
7. Roll the wire on the first servo pulley while bringing it closer to the servo shaft.
8. With the string tensioned, insert the first pulley into the geared shaft
9. Repeat the procedure with the second pulley
10. Finish by tightening the screw that holds the pulley stack onto the servo shaft

Note: After the set-in period you will need to re-tension the mechanism by disconnecting the pulleys from the servo side and repeating steps 5 to 10.

Video:

mmu_winch.mp4

Troubleshooting

Winch wires becoming loose

• This can happen due to the following
  • Your setup is new and things haven't stretched to their final length
  • The string is too elastic
  • The Servo pulleys slip from the servo shaft
  • There is too much force applied onto the arms causing the servo to buzz and stretching the pulleys to extreme