Mini Lathe Troubleshooting

Troubleshooting (10/06/07)

This page is long overdue. Several times a month, I receive emails inquiring about how to fix various common mini-lathe problems. I don't have much time to work on the page right now, but I wanted at least to provide a few comments and some links.

Some resources every mini-lathe owner should be aware of:

• LittleMachineShop.com (LMS) - stocks just about every part for the mini-lathe, plus a lot of accessories.
• The  Yahoo 7x12 minilathe group (this one is on-topic only.) Post a question about your problem and you'll probably get some good advice.
• As of April, 2012, Pete Brush is providing a repair service for the motor controllers.

Motor Controller

Particularly on models of the mini-lathe made before 2005, problems with the motor speed controller are one of the most common areas of trouble. LMS has created a great troubleshooting guide for controller and motor problems.

Usually, one of three components is responsible:

• MOSFETS
• Speed control potentiometer
• Forward/Reverse switch

MOSFETs are transistor-like components that act as high speed switches to regulate how much of the AC waveform is applied to the motor, thus regulating the speed.  One or both of the MOSFETS sometimes fail with the following symptoms:

• Motor does not run at all
• Motor runs only at top speed

Fortunately, if you have basic soldering skills, this problem is easy and inexpensive to fix.  Replacement MOSFETS are available from LittleMachineShop.com as well as various Internet electronic component sellers for about $5 each.

Don't want to fix it yourself? As of April, 2012,  Pete Brush provides a repair service for the speed control circuit boards.

Other Troubles

I don't have time at the moment to write this section. However, if you check out other areas of mini-lathe.com, you may find information that will help you to solve your problem. See the Tuning section, for example.