The Powerwall dolly
has spring washers to help prevent the lead screw from getting stuck at either end
of travel. However, the lead screw can bind if it hits the end of travel while
turning at high speed or high torque. To avoid hitting either end of travel, always
look at the stickers on the plastic shields (shown below) to know when the lead
screw is approaching the end of travel, and stop the lead screw before it hits the
end of travel.
If the lead screw does bind at the end of travel, follow the
steps in this procedure to unbind it.
Tools and Equipment
3/4” or 19 mm Wrench
Large vise grips
Torque wrench
5 mm Hex bit for the torque
wrench
Rubber or thick rag
Lay down the dolly and inspect
the base of the lead screw.
If the threaded shaft
collar has not moved and there is no gap between the threaded shaft
collar and the base washers, continue to step 2.
If the threaded shaft
collar has moved up the lead screw and there is a gap between the collar
and the washers, skip to step 3.
a - No gap between the collar and washer - go to step 2
b - Gap between the collar and washer - go to step 3
If the threaded shaft collar is
still at the base bracket, it is likely that the spring washers are fully
compressed and the drill cannot overcome the friction.
To unbind the lead screw, use the 3/4” (or 19 mm) wrench to turn the hex
drive clockwise (when viewing the screw from above). Test to make sure that
the screw rotates freely. If it does, the procedure is complete. If not,
proceed to step 3.
If the threaded shaft collar has moved up the lead screw, it needs to be moved
back toward the bottom of the screw.
The clamping screw is likely already loose, but if it is not, use the 5 mm
hex bit or an Allen key to loosen it.
Loosen this
screw
Use some rubber or a thick rag
to wrap around the threaded shaft collar and protect the finish. Use the vise
grips to hold the body of the collar, ensuring to only grab the collar.
Turn the threaded shaft collar
counterclockwise (when viewed from the bottom of the dolly).
Once the threaded shaft collar
is loose, thread it to the base of the lead screw. Make sure that the three
plates under the collar are stacked back-to-back and not resting on the screw
heads.
Rotate the collar until
the base rests on the washer
Use the 5 mm hex bit in the
torque wrench to secure the clamping screw on the threaded shaft collar to 16
Nm.
Tighten the shown screw
to 16 Nm
Test the system to ensure that the lead screw rotates freely.