ARC-170's Craftsman 101.07403 lathe restoration thread

It is just barely conceivable that the last time that you turned the motor off that there was a charge left in the Start capacitor. It is unlikely that any is left by now but if you want to be certain, unplug the line cord, turn the motor switch ON and with an insulated screwdriver, shor the two flat pins of the male plug together. Assuming that the centrifugal switch has closed by now, that will discharge the capacitor.

Other than that, there is nothing else in the motor to worry about.

I haven't seen a good photo of the bearing carrier on the wiring end of the motor to see whether the bearing end is open or not but after you pull the nuts off of the four long tie-bolts, I would cut some blocks or spacers and jam them in between the motor pulley and the pulley end of the motor to ensure that when you pry the wiring end bearing carrier out of the motor body that the armature doesn't pull out of the wiring end of the motor. There will be some wires that will follow the bearing carrier as you separate it from the motor body. Be careful of those. Part of the centrifugal mechanism will be attached to the armature and part of it including the switch itself will be attached to the bearing carrier. There will be a flat metal disk attached to the arms on the armature that moves towards the switch as the motor speed comes up. It will push on the switch actuator opening the switch. If it looks like it moves, oil it! And tight is good enough.
 
I got it apart. Here is the cap end. The copper pieces move, but there's nothing that looks like it has or gets oil.
DSC00073.JPG

On the motor shaft is a plastic disc that can be pushed down. Here it is up:
DSC00075.JPG

Here is it pushed down:
DSC00076.JPG

This mechanism makes the same clicking noise I hear when the motor is on. Again, there doesn't seem to be any obvious place for lube. There was a little oil by the washers on the shaft. Let me know if/where this gets lube.
 
Any place where two different pieces of metal rub together should get a drop of oil. Including the spring ends or eyes. Most of the oil will quickly sling off but if you oil everything in sight, you are sure to get the offending location. After you've oiled everything, push the plastic disk in and out several times. The click that you hear as the motor costs to a stop should come from the switch, not the actuator. However, those switches don't look like any I've ever seen. Could be Chinese.
 
48A. Could I use the open gear lube I use on the change gears? I thought I would apply it with a q-tip.

48C. The copper pieces referenced above don't actually move; they just ride on a contact point. Sorry if that caused any confusion.

48D. The case on the motor has "Made in USA" molded in. I wonder if the innards are Chinese? I couldn't easily find anything about COO on those pieces. The case appears to have been painted sometime in the past; I found what appears to be overspray on the inside..

48E. Would it hurt to spray compressed air inside the motor?
 
48A. It probably wouldn't hurt anything but I think that I would just use oil.

48C. What does move? And does the plastic disk move toward the bearing or toward the armature body?

48D. There is probably no way to tell.

48E. Probably not but keep the air pressure below about 40 PSI.
 
48A. I used oil. Seemed to help. If nothing else, it may have cleaned the contact surfaces a bit.

48C. The plastic piece is "at rest" away from the armature. The springs pull it in that position. This is the clicking noise I hear.

48F. I ran the motor and it seems fine. I did get a little spark at one of the connections when I switched it on high. This was after switching it on and off a few times to test it. The clicking seems to happen at the right time. I guess I need to just re-install it and use it and see what happens.
 
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What do you mean by "switched it on high"?

If the spark was at one if the studs where a wire or wires is connected, perhaps you did not tighten the nut.
 
wa5cab said:
What do you mean by "switched it on high"?

If the spark was at one if the studs where a wire or wires is connected, perhaps you did not tighten the nut.
Click to expand...

I have a 2-speed motor. Actually, it's a 3-speed but I only use two of them (it came with a 2-speed switch and I just kept it that way). The switch has high/off/low.

I may not have pushed the wire on the spade connector (no screws) far enough. I tried taking video, but there was no sound (older camera). I thought it would be interesting to hear the motor and see the spark.
 
OK. Does the spark show up most times when you start the motor or only that first time? If the latter, unplug the female, clean both sides of the male and reconnect, paying attention to fully seating the female. If the former, you can try all of that but if that doesn't fix it, you need to replace the female spade connector.
 
I looked at it again. I tightened the spade connector. The spark comes from the inside of the machine. From what little I know about electric motors, this is normal, right? The size of the spark did vary a bit as I turned the motor off and on at the various speeds. I let it coast to a stop every time. The clicking noise inside is more consistent, so the lube job must have helped.

I made a video so you can see it:
If the link doesn't work try searching for Atlas Craftsman lathe motor.

It's 1 minute 35 seconds long. I had the lights off and a light in another room on for a little ambient light (otherwise it was pitch black) so you could all see the spark better.
 
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