46-460 potentiometer

[Andrew LaPorte]

Looking for advice on replacement of the potentiometer, have (2) 46-460 lathes, one unit runs in reverse only, other unit just stops in the middle of a cut and then starts back up. Complete replacement assembly from Delta runs $400, new lathe $714. Any assistance greatly appreciated and thank you in advance for your time.

[Dwight Rutherford]

Pull the potentiometer and you should see a part number on it. Go to E-Bay and search the part number. You should get a hit or hits.

[Brice Rogers]

I looked at the manual to acquaint myself with your lathe. Here are some thoughts:

1. You mention the "potentiometer" but your $400 price for the assembly is actually for the speed control module. So, I wouldn't bother getting a new "pot". There is NO WAY that a potentiometer would cost $400. Also, a lathe that only runs in reverse is extremely unlikely to be caused by a bad pot. So, you're referring to a speed control module.

2. Your lathe that only runs backwards - - If it was me I'd turn off the power and check to see if the forward/reverse switch is working properly. I think on your lathe that the F/R switch is a slide switch? They are notorious for failing if dust gets in. But it is easy to "ohm out". If you aren't familiar with working with a digital ohm meter, I'd suggest finding someone qualified to help. The Fwd/Rev switch is the most likely component. But it could also be wiring (like a loose wire or connector, bad solder joint). But it could also be the controller. If you are able to troubleshoot the switch and it is okay, then change your focus to the speed controller.

3. The lathe that stops and restarts "could" be the potentiometer. Or a loose wire/connection. Or the controller. If it was me, I'd run it till it stops and then wiggle (rotate) the speed "pot". If that makes the lathe quickly start again, then - - yes - - replace the pot. If wiggling the pot doesn't do anything, then it is likely that the pot is okay. Again, here is a situation where you could (power off) check the pot with an ohm meter or (power on) with a volt meter. But only do a power on check if you have the skill and knowledge to do it safely. (I'm an engineer...). For something that is highly intermittent, I sometimes will "wiggle" the wiring to see if it changes anything or will use a spray can of circuit cool (a can of computer keyboard cleaner tipped upside down will do the same) and squirt it on various parts of your speed control board and connections to see if anything changes. Sometimes there can be a cold or fractured solder joint that is at fault - - so wiggling or circuit cool will help to isolate the problem.

If you have a schematic, please post it and I'll look at it and give you perhaps some better info.

[Richard Coers]

Brice is right on with his answers. You should be able to read for days about these 46-460 and electronic issues. That control board was an issue from the start, and back then no parts were available. Owners would buy a DC control made by KB Electronics along with a horsepower resistor of the correct size. https://www.amazon.com/KB-Electronics-KBMD-240D-Multi-Drive-Variable/dp/B00RW7LSXM/ref=sr_1_6?keywords=dc+motor+speed+controller+90v&pd_rd_r=e0c2597b-6421-4eb8-abc7-81134bf2c7d1&pd_rd_w=rJ9ZT&pd_rd_wg=g9pL5&pf_rd_p=4fa0e97a-13a4-491b-a127-133a554b4da3&pf_rd_r=RF44KZA3HGPFRD936T1N&qid=1646842925&sr=8-6

[Andrew LaPorte]

Thank you for the help, will look into the KB product, thanks again

[Mike Goetzke]

Pot is worth a shot - look at this: https://www.youtube.com/watch?v=PTrlqBqvcnI

[Paul Williams]

I have the early version of that 46-460 that has been running for 10 plus years with a few of your problems but have always been able to keep it running by blowing out the switches. Normally I just run my shop vac over the outside of the control box after every use. twice in 10 years I have had to open the box and blow the components out with an air compressor. My thought is that if I am still running this lathe when it finally quits, I will buy good quality sealed switches and pots and replace all three regardless of which one actually died. It is a pretty capable lathe except for the quality of the switches. It is too bad that Delta didn't fix this issue when it first came up many years ago. They could have saved their reputation for very little expense, by going to sealed components and mailing out replacements to the early lathes.