Motor Gear Cleaning and Reassembly

In this post I tackle the ugly job of removing all the nasty, 60+ year old grease gumming up the works in Ms. Rusty’s motor. 

I need to point out that this step really should have been done prior to all the wiring and motor disassembly that I did, but hey, I never claimed to be a professional!  However, because I did this step out of order there were a few precautions that I took, including:  protecting the new wiring from any grease/oil since that can cause premature deterioration, protecting the inside of the motor from any grease/oil since that can cause smoking, deterioration, and all kinds of other problems.

Ok – here we go! I first removed the grease caps which are located at the bottom of the gear case.

I also then removed worm gear by simply lifting it out carefully with a pair of bent nose pliers (recall that the armature was previously removed from the motor).

Then came the nasty job of cleaning the gear area and grease wick area.  This was done with the use of paper towels, Q-tips, toothpicks, and very small amounts of solvent (only when necessary).  The fruits of my labor can be seen below.

I then tried to replace the worm gear, but without all the grease it fell to the bottom and wouldn’t stay put.  So I then tried to put the armature in a bit and then use that to guide the worm gear.  Unfortunately, I wasn’t successful in replace armature, as it felt like something was in the way. 
At this point I felt absolutely stupid because after all this cleaning I had forgotten about the grease wicks, which of course with their springs, were in the way of the armature. 

(Now, if I were really clever and wanted you to think I was a genius I would have re-written this post and re-arranged these pictures to make you think that everything had gone according to plan.  However, life never goes according to plan and I am not a genius.  So I’m going to blog everything just the way it happens – for better or for worse!  Who knows, maybe some of you are reading this blog hoping nothing goes well much like some people watch an accident waiting to happen, or love American Idol tryouts just to watch the bad singers, and if so, I’d hate to disappoint you!  Anyway, I digress…)

Here are photos of one of the grease wicks in it’s tubes (also notice the brush tube to the left) and a picture of both grease wicks after removal from the tubes.

Surprise, surprise, the armature slide right in after grease wicks removed  
  Worm gear replaced 
The adjusters manual tells you to make sure that the “flat” part of the armature shaft can engage one of the two set screws.  The position of the “flat” part of the shaft is indicated by the “flat” at the cover end of the shaft.
  
At this point everything has been cleaned and/or repaired on the motor except for the motor cover.  That has bubbled and pitted paint due to rust and will need to be bead blasted and powder coated (or stripped and painted), but I’m putting it back on for now just to protect the coil and wires on the armature.  Isn’t it pretty?
  

Motor Wire Repair – Part 2

So what is an Underwriter’s Knot?  According to About.com:

“An Underwriter's knot is a simple and effect way to support the cord within the plug and give the connection some durability”

In this case, the knot is between the coil and the grommet in the motor case to prevent strain on the coil.  Here’s how to tie it as described on one of many websites.

Bend the left wire to the left into a loop, passing the end behind the body of the cord. Make a loop to the right with the other wire, passing the end in front of the body of the cord. Pass the end of each wire through the opposite loop and pull tight. Ta-da; an underwriters’ knot.

Here are a few pictures of what my knot looked like after I tied it.  I have to admit, practicing on spare wire helps quite a bit.

    

The next step was putting a new grommet in the motor case and then putting a larger piece of heat-shrink over both the red and black wires to connect them together and make it more aesthetically pleasing.  One problem I ran into was that I couldn’t get the red wire brass ring through the heat-shrink after the black wire had gone through (all this before shrinking of course).  So, my solution was to remove the brass ring from the red wire.  Here is what it looked like when I was done.  Not too bad, eh?

Well, I couldn’t get brass ring crimped back on to the red wire, so I decided to experiment with creating a “home-made” ring, which in the end worked out pretty well.  Here’s how I did it.

1. Strip your wire about 1-inch from the end 
2. Twist the exposed strands tightly 
3. Wrap the twisted strands around the tip of a pencil to form a ring.  The ring should be large enough, to fit around the post of the 3-pin terminal, yet not so large that it won’t touch the pin or fit in the pin cavity.
   
4. Apply solder to the ring so it has some rigidity and won’t come apart
   (front view) (back view)

I did several practice rings on scrap wire and and tested them on my 3-prong terminal to make sure the size was right before making the “real thing” on the end of the red motor wire. 

DISCLAIMER:  I don’t know know if this is the most appropriate way to finish off your wire, but it is aesthetically pleasing and does not harm the conducting properties of the wire.  I won’t be able to confirm how well it works until Ms. Rusty is back together again, so I guess we’ll find out together. 

In any case, it was fun making all the pretty rings and helped hone my soldering skills

Motor Wire Repair – Part 1

I first inspected the wiring near the coils and one of the wires was completely exposed right up to the entrance to the coil – not a good thing!  You will notice in the photos below that there is a knot in the wiring just below the coils.  This is called an underwriters knot and is intentionally placed above the grommet to prevent strain on the coils.  I’ll discuss this more a little later.

 

My assessment is that the wires will need to be recovered, at a minimum, and completely replaced, worst case.  So I decided to strip off the insulation of the current wiring to see the true condition of the wires.  The insulation was in such poor shape that it literally crumbled away when it was gently pinched between my fingers.  You can see just how bad it was in the next two pictures. I was even able to remove the insulation without even undoing the underwriters knot! 

    

Next came the wiring repair.  For this step I followed much of the advice given by Rain on the Vintage Singers group on Yahoo (see my Information Sources page).  However, instead of using 18 gauge wire as Rain suggested, my husband insisted on using 16 gauge wire because it would be less likely to overheat when I sew heavy duty cloth.  I don’t know if this is really necessary, but he is giving me his soldering gun, solder, and heat-shrink insulation to do this job, so I didn’t argue!

The “black” wire (the one I previously labeled with orange tape) was in good shape, so I simple put heat-shrink over the length of that wire. I first trimmed “red” lead from the motor coil (the one I previously labeled with purple tape) to about 4 inches and soldered it end of new red wire.  Then I put a piece of heat-shrink insulation all the way up to the coil and well past the soldered joint.

I then soldered the brass ring off the piece of wire that had been trimmed from to other end of this new wire and applied heat-shrink insulation over the soldered joint and up to the brass ring.

 

The next step is to tie an underwriter's knot to secure the connection of the wire and prevent strain on the coils.  I’ll cover that in the next post – stay tuned!

Motor Disassembly – Part 2

After removing the armature I cleaned the commutator.  I tried just wiping the little brass tabs using a soft cloth, but that wasn’t very effective.  As suggested by the Adjusters Manual, cleaning them with a rubber eraser did much better.  The photo below, and close-up, shows the commutator cleaned up as best as I could.
close-up: 
The next step was to unscrew 2 screws (shown below) to remove field core with coils. 

The manual warns to be very careful when removing the filed core so you don’t dislodge the wires soldered to the brush tubes.  This particular step was difficult for me because the melted and bad wiring connected to the motor became stuck in the outlet hole/grommet.  It was so bad that the grommet itself came out along with the wiring.
 
The next step was to clean the brush tubes.  I did this with a Q-tip dipped in a bit of solvent, and used the same technique to clean the bottom of the motor casing.  My brush tubes were in good shape so I didn’t remove them or the bushings – just cleaned them in place.
Next steps – take a close look at the wiring to assess what repairs will be needed.

Motor Disassembly – Part 1

In this post I’ll go over the first part of motor disassembly.  To prevent this from being an overly long and boring, I’ll break this into a few posts.

The 2 screws on either side of motor cover have to be removed before taking off the cover.  When removing the cover, I had to pry it off just a bit because it was stuck on pretty good. A little wiggling and a very small of prying got the cover off and without hurting any of the coils (very important!)

The next step is removing the brush caps and brushes.  Here is a view showing the brush caps just before removal and another the springs of both brushes exposed.   IMPORTANT – before you completely remove the brushes, mark them some way to  indicate their orientation prior to removal.  This is because the end of the brush has some curvature where the brush where it rubs against the commutator of the armature.    These next two photos show the brush after I put a mark on it to indicate orientation (but before removing it from the motor) and anther photo showing the curvature at the end of the brush.

 

I also added a “T” and “B” on each brush so I could remember which brush goes into the top or bottom of the motor.   I’m not sure if the T or B really matter, but I figure it can’t hurt since I’m labeling things anyway.

 

The next step was to remove the armature by loosing the set screws in the spiral gear.  If it weren’t for my handy Adjusters Manual I wouldn’t have even known these screws existed because they were so covered in muck/grease.  I removed some of the grease and tried to take a photo of the two screws, but I could only show one at a time (see below).

With both set screws loosened (I didn’t remove them for fear wasn’t sure I could get them back in again) I then carefully removed the armature – making sure I didn’t harm the coils in any way.

More to follow…..

Motor Removal

After the balance wheel is removed, taking off the motor is relatively easy.  You only have to remove 2 screws that attach the back of the gear housing to the head of the machine.  Then you just pull the motor from the head, with a little wiggling if needed.

Here she is without her motor.  You can see the two screw holes on either side of the gear shaft.

Front and back views of the motor after removal and close-up of the wiring

As you can see from the close-up, the wire covering is completely shot.   It should be interesting to see what the wiring looks like inside the motor (shudder).  I guess I’ll find out soon!

Lamp and Lamp Wiring Harness Disassembly

If you are not planning on doing a complete restoration of your sewing machine then you probably don’t have to do all the steps I’ve shown below.  However, for safety reasons, you do need to inspect the wiring connections on your machine to make sure they are in good shape.  At a minimum, check the wiring on the 3 pin terminal (Step 2) and the socket (Step 5).
Here are the steps that were required to remove the lamp assembly from Ms. Rusty.

1. Removed the sewing machine (Ms. Rusty) from the cabinet by removing two set screws from the underside of the machine base.
   
2. Removed the 3-pin terminal by removing the screw attaching it to the head (machine body).  I then labeled and disconnected each of the wires. 
   • Here is a picture of the 3-pin terminal after it has been removed.
     
   • Here is a picture of the terminal bracket after removal.
     
   • Here is a picture of the labeled wires after the 3-pin terminal and bracket have been removed.
     • Purple Tape = Pin 3 = Red wires: light and to motor
     • Orange Tape = Pin 2 = Black wires: motor & foot controller
     • Blue Tape = Pin 1 = Yellow wires: light & foot controller
        
3. I then removed the light switch from the 3 pin terminal by removing the knurled thumb nut and hex nut from the front of the switch. I then disconnected the light lead wire from the switch that is attached at the screw and labeled it with green tape. 
   • Here is a photo of the switch out of the terminal and with the light lead wire removed.  The wire that is still attached has been soldered on and I don’t plan on removing that right now.

   

4. Removal of the bulb and lamp shade:  Push and twist the bulb to release it from it’s housing.  You can then access the small screw on the lamp shade that attaches it to the machine body.  Once that is off you can access the set screw at the back of the shade to disconnect the shade from the wiring harness.
   • This photo shows the disconnected lamp shade and the screw that attaches it to the machine body (head).
     
   • This photo shows the set screw at the back of the lamp shade
5. Depending on your luck, the felt pad covering the back of the light assembly may either be in the lamp shade, fallen to the table, or still on the back of the light socket.  Mine was still attached to the socket and without the Adjusters manual I wouldn’t have noticed that it was hiding two screws.  After you remove those two little screws your wiring harness is now free!  Well, almost – see step 8
   • These photos show the felt covering the socket, the back cover removed from the socket (wires exposed), and the socket removed from the wires.
6. Then, according to the Adjusters Manual you need to remove the stitch indicator plate to see how the light leads are positioned inside the machine head
   • Front and back photos of the cover plate and washer
     
   • After removal of the cover plate and after removal of the washer
7. I then took photos of where this wire harness snaked through the machine
   • It makes 2 bends – 1 near the stich indicator plate and 1 near the bed
8. The next step was removing the set screw holding the light lead clamp.  Let me tell you that little bugger was hard to find because it was so covered in crud!
   • The colored end of the toothpick is showing where the set screw is located
9. After the set screw was loose, then it was relatively simple to pull out the lamp wire harness.
   • Photo of the wiring harness outside and in front of the of the head
     
   • Both lamp wires inside the harness and clamp
     
   • One of the wires removed from the harness

Initially I thought the lamp wires were in good shape, but upon closer inspection I noticed that they are rusted and starting to break off near the ends.  As a precaution, I have decided to replace all the lamp wiring in Ms. Rusty.  I’d rather be safe and confident the wiring is good and not have to go through this whole disassembly process again in the future.