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I have a 25 year old Grizzly lathe that has been worked hard.  The motor fried and took some of the control relays with it.  DOA...  So now I need to wire a replacement motor with the ability to reverse the rotation by means of a transformer/contactor and switch.  I've considered using two knife switches for KISS purposes.  Any help would be greatly appreciated.  Thx , Keith



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What model is it? Do you have a manual or a wiring schematic for it? What is fried in it? Pretty much anything that could be in that lathe should be available through Grainger or one of the electronics parts houses. 

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  • 5 months later...


So long as you're not controlling the speed of the motor, you could potentially use a reversible motor starter.https://www.superbreakers.net/2601ag2.html?gclid=COe_0KrH2M4CFQataQod6PsMWA

I would strongly encourage you to find an electrician to help with this. 

Here's a schematic that shows how it would be hooked up.


Knife switches are a very bad idea because they are an electrocution, arc, and flash hazard. 

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3 wire or 4 wire?..and I assume it's single phase.  In any case, there are a lot of diagrams on google images for the basic set-ups.  It appears you can also get into a lot of funky variations and "extras" so YMMV.  And of course remember it's the internet and Abraham Lincoln once reminded us that not everything you read on the internet is true. Double source or more.

Here's a simple one for a 4 wire but you'd need to figure out the relay switching of the leads:


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