Electrical ? for MM owners

[Bill Bolen]

Have you added a secondary on off switch to your lathe? I do a lot of HF’s and like having the on off switch stuck in the area of my tailstock when hollowing. For my old 1442 with just a 110 volt circuit this was a simple addition of a switch to break the circuit on one leg of the wire. On a 220 did you just switch one wire to kill the circuit? With the electronics involved in a VFD will the lathe come back on when you throw that secondary switch again or do you have to go to the headstock end and re set before you can power back on? As you can see I know just enough about electrical service to get myself in trouble...Bill.. …

[John Fricke]

I bought the auxilliary remote switch for my PM 3520B. It didn't come with any directions for installing. It's still sitting on the shelf until I get the time to find help to figure it out. If I remember correctly it is a pushpull similiar to the main switch. I hope this is an either or situation where you can use either one .

[Ken Glass]

William,
I will wait with you for an answer. I would like to have a switch for my 3520B in the same area as you have yours located on the 110V lathe. I hope someone pipes in with an easy/low cost solution. I was thinking it would have to be a double pull/ double throw switch, but would like to know for sure.

[Steve Schlumpf]

Well........ I have the Jet 2hp, 220 volt version (the Mustard Monster's little brother), and wired an on/off switch using a regular 120 volt wall switch, a plastic junction box and a rare earth magnet. The switch can be placed anywhere on the lathe and if it ever breaks - I can replace it for $1 or less if I can find a regular light switch on sale.

I created a PDf of the process I used, emailed it to a friend who has the MM and he was able to follow the directions and get his switch wired with no problems. If this is something you might be interested in - PM me with your email address and I will forward the PDF to you. Also, please understand - this is electrical and if you do not know what you are doing - get someone qualified to install the mod for you.

[David Walser]

Please forgive my ignorance, but couldn't you install a switch into the power cord -- between the socket in the wall and where the power enters the lathe? Attach that switch to the tail stock (either permanently or via a magnet) and you'd have the ability to shut the power off at the tail stock.

[Bill Howatt]

Yes, you could. To make the scheme work all you need to do is break one of the wires although this generally is not recommended for safety reasons on 240V circuits. I would also use a switch rated for 240V.

In my case, I put a switch/box in the wiring supplying the receptacle the lathe is plugged into. The switch is for emergency use only. Since then I modified my General to move the On/Off pushbuttons and the variable-speed control pot to a box on the end of a cable that I can put where I want it.

For General 260 owners and perhaps other lathes as well, the On/Off pushbuttons have 240V on them not a low control voltage so be careful if you consider any modifications to them.

Bill

[Dennis Ford]

If you have a VFD drive, it is not a good idea to switch its power off while the motor is turning. The voltage spikes produced by doing this is harmful to the variable frequency drive. An additional on/off switch should be wired into the control circuit, not the main power.