Fixing a Broken Motor Cap Screw

This Featherweight Hint has been provided to us by Brad Sawatwipachai.  Brad is a friend and Featherweight collector in Ontario, Canada.  He recently hosted his first Featherweight Maintenance Workshop and posted photographs of something he had to remedy while in his class.  This has been something we have had to do as well, so we thought it would be good timing to feature Brad and bring another hint to you.

 

Each Singer Featherweight Motor has two motor cap screws.  The one on the top of the motor and one underneath (the one underneath is accessed from under the machine).  These screws are made of Bakelite and are quite brittle from age.  If you need to check the condition of the motor brushes the motor cap must be removed.  If your motor cap is not broken, DO NOT OVER-TIGHTEN, because over-tightening is usually the cause of breakage.  If you’re not careful (or sometimes, even if you are), the motor cap can break apart, and you’re left with a stem or partial.  This can be pretty discouraging because now you not only have a broken motor cap but you still haven’t been able to access the motor brushes…. well, there is a remedy and Brad has illustrated his steps below.

 


Tools to Remove a Motor Cap Screw from a Singer Featherweight Motor
(Photo Courtesy: Brad Sawatwipachai 2015)

  

1. Use an Olfa cutting knife to score the leftover stem of the motor cap.
2. With a metal ruler, deepen the mark that you made with the knife.
3. The tip of the screwdriver should now go into the groove, allowing you to unscrew what is left of the old motor cap.

 

 

If you have a 110-volt motor that has a motor cap screw measuring 3/8 inch then replacing it with another one is easy… we carry those in our shop here.  Some UK motors had a larger motor cap screw, so if your motor cap is 1/2 inch then give us a call and we might have an original in stock.  Originals are fragile so they can be a bit more difficult to procure all in one piece – so be careful!  Just remember – do not over tighten the motor cap screw – “finger tight” is sufficient.  Thanks again, Brad, for letting us use your photos and input for this Featherweight Hint.

Another issue that occasionally happens regarding the motor cap screw pertains to the brush housing and threaded piece that holds the motor brush cap.  This piece can become loose and will pop up from the motor housing itself.   If this happens, there is a set screw located inside the motor housing and at the bottom of the screw hole for the main motor housing connecting screws.

A simple fix -- push the brush housing back down and tighten the set screw, then reassemble the motor.   It is best to remove the motor brushes while completing this task.