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Prewar lathe issues

JSP

Plastic
Joined
Apr 28, 2021
Short version: need help with motor. It's making a clicking noise which it hadn't previously had. It's getting louder. Is there an easy fix for this, or how best do I find an appropriate replacement?

Background:
My grandpa bought a soth bend lathe after the war. He was a tool a die maker. He died about 20 years ago, and my dad inherited his machining tools. We use it occasionally for miscellaneous projects.

Current events:
I started machining some delrin pieces for my race car. We heard a clicking noise in the motor that just started. It's getting louder. I'm not sure it's a bearing issue. I did a little searching and found where to grab the serial number of the lathe. I also found the Steve wells website that based on the number (81465) dates this machine back to late 1937 early 1938.

Is this a common issue with these motors that can be disassembled and fixed or do I shop for a new motor? What's the best way to make sure I get something that works correctly? I haven't started taking it apart yet, but I'm not yet finding any labels for a catalog number or motor number or any of that.
 
We have no clue what your talking about without more information.

Swing of lathe?
HP of motor?
Model number of motor?
Configuration? (Motor in the cabinet under lathe or line shaft drive?)
 
My dad managed to get a blurry picture of a label on the bottom of motor. It's a delco motor. 3/4hp. That's all the information I was able to get from the picture of the label. The power at the house is single phase 110v. The lathe has a set of 3 pulleys for speed control. The shaft at the back has another pulley that connects by belt to the motor mounted on a bench top.
 
The swing of a lathe generally refers to the largest diameter that a lathe can turn (in the chuck) without hitting the bed.
For example, a 9" lathe can hold and rotate an object no larger than 9" in diameter assuming the center is in the middle.
It's just a classification of lathe sizes such as 9", 10", 13" 16", etc. So if your lathe is about 4.5" from the center of the simple to the bed,
then it is a 9" lathe.

This really only becomes an issue for a motor because generally, the larger the lathe (swing), the more horsepower is required.

I don't think there's too much to these old motors, and I would not be afraid of taking it apart....but take LOTS of reference photos as you do.
The clicking could be anything from a bearing to an obstacle that has found its way up into the motor. Try to isolate which end the noise is
coming from. Carefully take it apart and check the bearings and/or look for junk in the works.

Who knows, it may be a simple fix.or may not be. At the most, it might be time for a replacement.
If you are using a reversible drum switch, be damn sure you record what wires go on what terminals!!
You can see the havoc in the threads below.

BTW, make sure it's not a belt making the noise instead of the motor. You will probably need to remove the
motor for bench work.

PMc

View attachment 320097 View attachment 320098 View attachment 320099 View attachment 320100
 
Without being nearby to check right now I'd guess it's a 7 or 9". There is a forward and reverse control switch unit.
 
How often does it click? Is the click in phase with the spindle movement? +1 on checking your belts first for problems. It also could be a centrifugal switch that is sticking. Or a bearing.
 
are you sure it is coming from the motor? did you remove the belt from the drive pulley on the motor to isolate it from the gear train and when you turn on the motor do you still hear the noise?
 
Sorry for the late response. We did disconnect the belts to isolate the noise. We started disassembly and discovered a very loose set screw on the pulley on the motor. Tightened it up and it was fine.
 
Sorry for the late response. We did disconnect the belts to isolate the noise. We started disassembly and discovered a very loose set screw on the pulley on the motor. Tightened it up and it was fine.

That's good news...thanks for update.
 








 
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