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PM3520B Switch help

R

Ricc Havens

Joined
Feb 21, 2011
Messages
391
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358
Location
Elkhart, IN
Website
www.riccsdesigns.com
My fwd/rev switch is acting up. Runs in forward but not reverse. I have done forum searches and google searches and not having any luck. Searches come up with results on the red on/off switch and the potentiometer. Even the old Mustard Monster forums that were converted to documents on Doc Green's site only speak of the pot and on/off swtich or the VFD. Nothing about the fwd/rev swtich.

Even a google search for 3520b replacement forward reverse switch comes up primarily with results for the option remote on/off switch. Anyone have any suggestions on a replacement switch?

Thanks!
 
McMaster-Carr part number 7343K751

You may have to swap out the quick-connects terminals on the lathe. My lathe has 3/16 female connectors, and the switch has 1/4 pins.
 
It’s a pretty basic switch, also probably available at a well stocked hardware store if you ask someone who knows where to look. These are what you need to know:

2 position On-On not On-(On) toggle type
3 pins, ideally 3/16 quick-connect terminals
10A or better, 125V
Sized for 1/2” knockout
 
Ricc Havens said:
My fwd/rev switch is acting up. Runs in forward but not reverse. I have done forum searches and google searches and not having any luck. Searches come up with results on the red on/off switch and the potentiometer. Even the old Mustard Monster forums that were converted to documents on Doc Green's site only speak of the pot and on/off swtich or the VFD. Nothing about the fwd/rev swtich.

Even a google search for 3520b replacement forward reverse switch comes up primarily with results for the option remote on/off switch. Anyone have any suggestions on a replacement switch?

Thanks!
Click to expand...
Mine did this. Powermatic tech said to blow it out with compressed air and keep a sandwich bag over it; have had no problems since.
 
A friend of mine had this happen to his and Powermatic told him to blow the switch with the compressed air and flip the switch back and forth several times and it fixed it for him. I had the same thing happen to my 3520C and I did the same thing and it corrected the problem.
 
If anyone is interested this switch is what I got and worked for me. Powermatic wanted $30-$37 plus shipping depending on the parts source. This one from Amazon was about $7. I was back up and running in less than 20min.

Amazon.com

www.amazon.com

Note: I am not an electrician or repair tech and make no express warranties. It worked for me but do it at your own risk.
 
Ricc Havens said:
If anyone is interested this switch is what I got and worked for me. Powermatic wanted $30-$37 plus shipping depending on the parts source. This one from Amazon was about $7. I was back up and running in less than 20min.

Amazon.com

www.amazon.com

Note: I am not an electrician or repair tech and make no express warranties. It worked for me but do it at your own risk.
Click to expand...
I also have a PM 3520. The switch is occasionally unresponsive. I'd like to see how you attached the new switch to your Powermatic. Can you give us a couple of pictures?
 
Larry Mercier said:
I also have a PM 3520. The switch is occasionally unresponsive. I'd like to see how you attached the new switch to your Powermatic. Can you give us a couple of pictures?
Click to expand...
Larry, sorry I did not take any photos. I also did not change the location and mount the fwd/rev switch in a different location than it's normal location on the control panel. All I did was unscrew the two screws holding the control panel buttons on the headstock. I marked the three wires on the fwd/rev switch. The middle wire is power and for my PM3520B the bottom connector/wire on the switch is reverse, and the top wire/position on the switch is forward. I loosened and remove the thin locking nut on the front of the fwd/rev toggle switch body. and removed the power wire and installed it onto the middle location of the new switch. Then I transferred each of the other wires to the new switch. Then placed the new switch into the mounting hole on the control panel and replaced the nut holding it into place. When you plug the lathe back in and ru n the maching - if it runs in reverse when you have it in your normal forward position and forward in your normal reverse postion you have two options for a quick fix. 1) remove the switch and swap the two wires on the outside connectors leaving the center wire where it is. 2) easiest - loosend the mounting nut and just rotate the switch 180deg and re-tighten the nut.

NOTE: The factory switch, and the replacement switch, do not have any specific forward or reverse marked on the switch. The middle wire/connector is power, and the two other connectors are the same and complete the circuit when the switch is moved to either position. The switch is called a SPDT on-on switch (single pull/double throw). So the either of the two positions is an ON position. It just toggles back and forth between the two positions. There are SPDT switches available with a center off. These have three physical positions - on -center off-on. You do not want this switch. You already have an OFF switch which is the big red muschroom switch.
 
Ricc Havens said:
. There are SPDT switches available with a center off. These have three physical positions - on -center off-on. You do not want this switch. You already have an OFF switch which is the big red muschroom switch.
Click to expand...

Ric, thank you for a very well-written response. The PM3520c has a moveable control box. The four controls on that box are: FORWARD (green mushroom button), STOP(red mushroom button), fORWARD/REVERSE (toggle switch) and a SPEED CONTROL (rheostat). I am wondering if these changes between the PM3520B and C versions will prevent me from upgrading my control box. Help would be appreciated.






































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Larry, I have not seen a PM3520C model in person so I am not sure I can help.
The B model only has three controls on the front, The red mushroom on/off switch, below that is the fwd/rev toggle switch and below that is the speed potentiometer/reostat. I am assuming the fwd/rev toggle is pretty much the same thing on the C model as it is on the B model. The fwd/rev toggle on the B model was out of stock on a couple websites that sold Powermatic parts. It claimed being discontinued but had a replacement part number of Jet 1642-141. Which is the fwd/rev toggle on the Jet 1642 lathe that was sold years ago. (now replaced by the Jet1640EVS). I went and looked at a fellow club member's older Jet 1642 and sure enough it was the same toggle for the fwd/rev as the PM3520B.

As far as upgrading your "C" model control box - I'm not sure what you are looking to do. If you are looking to convert it to a moveable box to move the controls to the tail end of the lather or other location I am assuming it can be done. I did it on my "B" model following the instructions on this website It worked out well for me and you could probably adapt it for your lathe but may need a different style box that what is used in these instructions since you have the extra green switch that the "B" model doesn't have.

I would suggest starting a new discussion thread for the PM3520C and explain what you want so other C model owners can see you need help. They may not be looking at this discussion since it's titled for those with B models. Good luck!!
 
Ricc Havens said:
I would suggest starting a new discussion thread for the PM3520C and explain what you want so other C model owners can see you need help. They may not be looking at this discussion since it's titled for those with B models. Good luck!!
Click to expand...
Thanks Ric, I greatly appreciate your help.
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