Need to replace electrical switch on my 818P Jet metal bench lathe with milling head

[ShopShoe]

Ken,

Thank You for a very understandable description. I couldn't foresee the "creative license" that the manufacturer may have put into this. I can see how this type of design would work very well for a motor powering a lathe.

If the motor can be found OK, then it looks like the OP is back to a substitution for the switch, which is do-able. However, In looking at the V10 postings, I see the discussions regarding finding a 3-phase motor and using a VFD. I also see the discussions point out that the motor size and mountings make finding one hard.

yellow_cad,

I don't know your comfort level in all this, but it looks like some advanced troubleshooting is required at this point.

I think, without knowing what that analysis would find, that you are back to creating a substitute for the switch. The latching functions and interlocks incorporated mechanically in the original switch will have to be done through another combination of functions.

Let us know how it goes.

--ShopShoe

 

[Ken I]

I see the discussions regarding finding a 3-phase motor and using a VFD. I also see the discussions point out that the motor size and mountings make finding one hard.

Again - refer my rewinding a single phase to three phase - particularly relevant when changing the motor is difficult.

Single Phase To Three Phase Rewind - Lathe Uprate

Or go through the attachment.

Regards, Ken

 

[yellow_cad]

All I can gather since the manual is silent is to start the lathe and run in forward high speed, I would need to first press the low speed forward and once at speed, then push the two high speed switches together as one (since I am missing the button for this). I was on the lowest gear speed to benefit the motor, but when I did press the two high speed switches, the spindle actually slowed down.

Before I had read that it was apparent that the manufacturer always intended for both high speed switches to be pressed together, I did try to first get it to speed in low forward and then pressing only the high forward switch. The speed did not increase and in a short time smoke exited the motor area.

I am only guessing, but when I found this lathe/mill 10 years ago it was sitting neglected with mill in the pan so I got things going. It only had three buttons, forward low speed, stop, and mill. I could definitely see that with the one button controlling two switches for high speed missing that in the 30 years before I got it, many people may have tried to run high speed with only one of the high speed switches (since the button that pressed two switches together was missing) abusing the motor a little bit each time.

At this point, since I'm not electrically dumb, but it is not my strong suit, I am inclined to be content with low speed only for the lathe and use a free standing motor mag switch to operate the mill motor.

 

[Ken I]

Starting to sound like you've lost a winding along the way.

Stick with the low speed if that suits you - but sooner or later its going to turn to smoke - if you then have go to the trouble of having it rewound, you might as well go to the trouble of rewinding it to 3 phase and use an inverter to drive it.

As long as the number of slots in the armature are a multiple of 3 and 4 it's doable - so 12, 24, 36 slots can be rewound from 4 pole single phase to 4 pole three phase.

My own lathe is a joy to use since the conversion - prior to that its underpowered quirkiness was a disappointment.

Regards, Ken

 

[yellow_cad]

What is the correct schematic for the switched linked below to run the 1/4 hp mill motor? Is it just hot wire 32 to 31, and neutral 22 to 21?

https://www.amazon.com/BVPOW-Button...tor+switch&qid=1638566087&s=industrial&sr=1-4

 

[Ken I]

Yes - that just appears to be a two pole switch direct to the motor with one of the leads branching via the capacitor.

Regards, Ken