Tuesday, December 27, 2011
How to Re-wire a Potted Motor, Part 16: Re-attaching the Field Core
Now we’ll begin closing the motor back up. Please orient your motor as shown in the photo above, which is the way we had it in Part 15.
Then note that there will be a potential problem in closing it up, as seen below:
If we’re not careful, the bottom motor lead will block one of the screws that attaches the field core to the rest of the housing.
To prevent this, we insert that screw prior to closing up the motor.
Insert the screw all the way, and tuck the motor lead behind the screw.
Then, as we begin closing the motor, we ensure that wire stays behind the screw.
The tricky part is that we must guide the screw into the screw hole. This may take you a few tries.
Once you feel you’ve got the screw properly seated against the hole, test it with the screwdriver and see if you can tighten it.
If it does not want to easily tighten, STOP and try re-seating it. If you get the screw in at an improper angle, you can strip the threads, which is bad news.
Once you feel the screw going into the hole properly, begin tightening it--but don’t tighten it all the way. Get it up to about the point shown in the photo below, leaving a gap between the core and the housing.
Then we turn to the other screw we need to do on the other side.
Don’t forget this side is the one that has the motor information plate. Hold that in place.
Then insert and begin tightening the screw on this side. But again, don’t tighten it all the way; leave a gap, as on the other side.
Now we look inside the motor. We want to be sure there are no errant wires sticking out, which would interfere with the armature.
Here you can see the brush lead is neatly tucked away to the side, as it should be. Check to see that the other side looks the same.
Once we’ve confirmed there is no wiring sticking out, we go back to the first screw and tighten it all the way.
Then do the other side.
And that’s that, the motor housing is now ready to accept the armature again.
Go on to Part 17: Cleaning the Commutator