The Z-axis holder can prevent the free fall of extruder head when printer is powered off. It uses a one-way bearing which apply friction to the Z-axis motor shaft when the Y axis move downward.
The amount of friction can adjusted by a screw. We do not recommend applying too much friction as it may cause the Z-axis motor to loose steps when moving downward.
The kit will become a standard setup for the future productions so it is released to keep current users up-to-date. To install it user need to have super glue or something equivalent.
Step 1. Click the picture below, download and print the Friction Cup model from Moshop.
Step 2. Remove the motor shaft clip on the Z-axis
Step 3. Clean the shaft and pulley, make sure no oil/grease is left.
Step 4. Apply super glue to motor shaft and pulley.
Step 5. Put the steel barrel onto the shaft, make sure it is glued firmly. Then remove the lower left screw on the motor.
Step 6. Assemble the part, make sure the side of bearing with marking is face outward. The bearing should be holding the barrel.
Adjust friction by tightening the screws.
I know you are thinking about the blackout recovery function. However we still cannot guarantee it will work with this mod, since the friction adjustment is not very precise and stable.
When powered off, the extruder head could move down a little bit before holding its position, this could cause error to the resuming point so try it with your own risk.