How to Re-wire a Potted Motor, Part 20: Hooking It All Back Up

Now we’re at the final step to getting your machine back up and running!

Start by sliding your newly-renovated motor onto the shaft.

How to Re-wire a Potted Motor, Part 19: Re-installing the Brushes and Grease Wicks

 

With the armature and worm back in place, we’re now ready to install the final items: The brushes and grease wicks, and then we'll re-fill the grease tubes, as seen above. 

We’ll start with the brushes.

How to Re-wire a Potted Motor, Part 18: Re-installing the Armature and Worm

Folks, we’re now very close to the end. Having succesfully completed the actual re-wiring, your machine should now be up and running in no time. But first we have just a few more mechanical steps to get through.

Now we'll start closing the motor up, in preparation for re-attaching it to the rest of the machine. First, grab the worm, and I’ll show you a little time-saving trick.

How to Re-wire a Potted Motor, Part 17: Cleaning the Commutator

Now that our potted motor has been rewired and is partially back together, we need to put the armature back inside. But first we ought to clean the part of the armature called the commutator. The commutator is the series of copper bars arrayed in a ring. They are what the motor brushes make contact with, and they need to be smooth and clean so that electricity can be transmitted between commutator and brush.

The Singer manuals all say to clean your commutator with nothing more than a pencil eraser, but in practice that’s never worked for me. Perhaps it was a valid fix five or ten years into the life of the machines, but some of mine are from the 1930s and require more aggressive cleaning techniques involving a power drill and some sandpaper. The best thing to use is actually a rubber honing stick, but as I'm guessing most of you don't have access to those, I'll show you how to do this with sandpaper you can find in any hardware store.

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.

How to Re-wire a Potted Motor, Part 15: Soldering On New Motor Leads

Now we’re finally ready to solder new motor leads on. Again, please ensure that your motor is oriented exactly as in the photo below, to ensure my explanations of “top/bottom” are correct:

Motor oriented with field core at left, bobbin winding assembly at top right.

Ready? Let’s begin.

How to Re-wire a Potted Motor, Part 14: Replacing the Motor Housing Grommet

I almost forgot! Before we take the big step of soldering the new motor leads on, there’s one more thing we ought to check, as this is easier to do while we’ve got the motor leads clipped and out of the way. Take a look at the rubber grommet covering the hole that the motor leads will eventually go through.

Here I can see this one has a crack in it:

How to Re-wire a Potted Motor, Part 13: Cutting and Prepping the Motor Leads

Now that we’ve got the motor as open as possible, we’re going to cut the motor leads at specific points to prepare for soldering new ones on.

First, very important, please orient your motor as shown in the photo above: The field core is to the left, the bobbin winder is at the top right. We need to have our motors oriented the same way so when I say “right/left/up/down” you’re not getting confused and cutting the wrong thing.

How to Re-wire a Potted Motor, Part 12: Detaching the Field Core

Now we need to access the motor leads so we can replace them. To get to the motor leads, we need to detach the motor’s core, or field core, from the motor housing. As you’ll see, we cannot detach it completely; although we will physically separate it from the housing, it will remain attached via two wires. (In the photo up above, the two wires in question look like water mocassins.) We must be careful not to disturb those two wires.

The first thing you’ll need to do is remove these two screws.

How to Re-wire a Potted Motor, Part 11: Armature & Worm Removal

With the grease wicks removed (and the motor brushes if they were willing to come out), it is now time for us to crack the motor open. In this entry we will learn to remove the motor cover and perform the crucial task of safely removing the armature. We will also learn the difference between a worm and a worm gear.