# The motor on my lathe quit



## n4zou (Feb 10, 2012)

My lathe motor quit. I'm not going to complain too much about it because it's 24 yrs old. The motor is a Chinese 1 1/2 HP, Capacitor start, single phase induction type. I pulled out the motor and removed the end cover over the centrifugal switch and found it had burned out. The exact replacement switch is no longer available but I did find that TORQ has a replacement for it. The replacement switch is a TORQ S-6013. The catalogue lists it's cost at $11.50 plus shipping. I've tried calling but they are closed Friday, Saturdays, and Sundays. You must call or e-mail them to request current prices and shipping quotes. The original switch looks rather cheap. I'm really surprised it's worked 24 yrs. If you have machinery with Chinese motors you may want to go ahead and order a replacement switch and have it ready to go. You can't believe the feeling I have now not having my lathe operational.
http://www.torq.com/replacement.htm
Below is a picture of the switch. The contact on the doughnut spring is completely burned away.


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## n4zou (Feb 10, 2012)

Update: I must have called when they were at lunch! I just ordered two switches at $15.20 each. From now own I will keep a back-up switch for every single phase motor I have in my shop. I also ordered a replacement switch for the motor in my mill too.


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## rake60 (Feb 10, 2012)

I think it's great that centrifugal switch lasted 24 years! 

Rick


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## n4zou (Feb 11, 2012)

24 years without any issues is not bad at all for a lathe made in China. I just replaced the motor to jack shaft belt 6 months ago. The belt between the jack shaft and spindle has a few ragged places so I ordered a link belt so I would not need to remove the spindle to replace that old belt. I'm going to keep using the old belt until it craps out like the other belt did. A friend came by with a nice Dayton 2 HP capacitor start and capacitor run reversible motor that will fit my lathe and gave it to me! It has a bad bearing next to the output shaft. I hooked it up before I disassembled it and found it runs very good except for that howling bearing. I already have it disassembled so I can take both bearings to the industrial supply shop in town and buy replacements. I found a couple of pulleys on Amazon.com that will take the place of the multi-step pulley on the Chinese motor shaft. I can't reuse the Chinese pulley because the motor's spindle is a metric size. I'm going to put the Dayton motor on my lathe and keep the Chinese motor as a backup. The Chinese motor never liked pulling the spindle over 1,000 RPM or higher anyway. I guess I should have replaced it years ago just for that reason but I hardly ever needed to run it on the high range settings.


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## modeng2000 (Feb 12, 2012)

When the start switch broke on my Hobbymat lathe I didn't replace it with another centrifugal switch.

Instead I made an electronic timer that energised the start winding just long enough for the motor to get up to speed and then disconnect. The actual switching of the power to the motor start winding was by relay rather that using a semi-conductor to keep things simple and the time delay was controlled by a monostable multi-vibrator. The energise time was around 2 to 3 seconds and was triggered by the lathe power switch.

John


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## n4zou (Feb 15, 2012)

The TORQ centrifugal switches came in about 2 hours ago. The replacement switch is radically different than the one that burned up. It aligned with the switch mounting bracket and the original mechanical part that is connected to the shaft worked perfectly with it as well. I had to extend the length of the wires and modify a couple of push on wire terminals so they would clear the rotating switch actuator. While the motor was out of the lathe awaiting the switch I went ahead and pulled it apart and replaced the bearings. The local industrial supply shop had the bearings in stock. I cleaned all the dust/dirt that had collected inside the motor before putting it back together. I also replaced the starting capacitor too. The nice lady at the gas and electric supply shop wanted to check it before she would sell me a new one. It turns out it was bad too and may have burned up the switch. The motor has never run as well as it is now. I think the bearings and capacitor have been bad for years. I actually thought something was wrong with the lathe the first time I cranked it up! Before all this work was done I would turn it on and it would take a moment or two to get up to speed. Now it's at speed almost instantly, even at it's 1500 rpm top speed setting. It's so nice having my lathe operating once again. I'm also in the process of rebuilding a motor a friend gave me that I will use as a backup. The place that had the bearings did not have the bearings in stock for the Dayton motor my friend gave me. I'm ordering them on-line myself. I received the pulleys I ordered for it Monday this week. They worked out perfectly to replace the pulley on the original motor. When I'm finished I'll have a backup motor that I can switch out in less than an hour. A picture of the new switch is below.


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