Eliminating zero speed start on a dc motor control

[rrrickert]

I have read this (see below) but the person did not say what wires to put the cap onto. This seems like a way to keep the soft start but eliminate the zero start. And it sounds like it might work for any treadmill motor controller. I am using this in a drill press. I need to keep the set speed between holes. Thank You.

This is the copy from someones else's post.

"I have developed a simple way to bypass the MC60 motor controller requiring returning to zero speed before starting.
Simply place a 100uF/50v cap between the black and white terminals with the negative leg on the black.
The cap acts as a temporary short, simulating turning the speed to zero. Now you can set the speed, turn it off, turn it back on without changing the speed setting."

 

[ChazzC]

I have read this (see below) but the person did not say what wires to put the cap onto. This seems like a way to keep the soft start but eliminate the zero start. And it sounds like it might work for any treadmill motor controller. I am using this in a drill press. I need to keep the set speed between holes. Thank You.

This is the copy from someones else's post.

"I have developed a simple way to bypass the MC60 motor controller requiring returning to zero speed before starting.
Simply place a 100uF/50v cap between the black and white terminals with the negative leg on the black.
The cap acts as a temporary short, simulating turning the speed to zero. Now you can set the speed, turn it off, turn it back on without changing the speed setting."

My MicroLux Mini-Lathe & LMS Mini-Mill will re-start from any speed; you only need to return to zero is there has been a fault.

 

[rrrickert]

Most treadmill controllers force the return to 0 for safety.

 

[markba633csi]

Probably the cap would be connected between the O volt terminal of the pot and either the wiper or the top terminal:
I'm guessing it's likely the second way as that wouldn't affect the action of the speed control knob and make it sluggish to respond

 

[Jake M]

I agree with the above posts, the zero start is built into every treadmill, otherwise somebody's gonna get hurt. The thread you posted did specify what to hook up and where, but it's specific to that controller. It fools the logic in the controller to think you started from zero and dialed up quickly. While the theory may well apply to many (most?) controllers, the wiring will not necessarily be the same colors from one to the next. Markba633ca is on the right track. You've got to use the capacitor across the signal and the reference. I'm suspecting that option 1 in his picture is the most likely. You may also have to use more or less capacitor, depending on if the controller is smart enough to recognize what's a plausible (safe) rate of change to accept from the pot without hurting a treadmill user. Bigger won't be better though, as it's gonna start to compromise the response to your speed changes at some point.

 

[Forty Niner]

I have a treadmill motor on my Taig lathe. I found very useful information and put it in a word file. Included is a modification to start and stop without returning to zero. It is called the Pause / Resume switch in this document.

 

[rrrickert]

Probably the cap would be connected between the O volt terminal of the pot and either the wiper or the top terminal:
I'm guessing it's likely the second way as that wouldn't affect the action of the speed control knob and make it sluggish to respond
View attachment 467269

Thank you!! If I would have just looked up the wiring for an MC60 control board I would have seen the black and white wires and figured it out. But this way someone else might be able to use this info also. The board I am using is a Minarik MM21030A Model KK6039T. I will be ordering the caps today. I will let everyone know if it works in a couple of days.

 

[rrrickert]

I have a treadmill motor on my Taig lathe. I found very useful information and put it in a word file. Included is a modification to start and stop without returning to zero. It is called the Pause / Resume switch in this document.

Thank you. Nice job on your controls. The problem with that solution is I use a foot pedal to start and stop the drill press. So I would still have to reach up and push a button. I was looking for a different way to do it so the foot pedal would work properly. I had one set up before that worked but lost it all in a shop fire. Starting from scratch is no fun.

 

[markba633csi]

It looks like there is another way to do this which is shown in the article
The wiper circuit is opened with another switch to stop the machine which would reset the return-to-zero circuit
Might be better than a cap

 

[rrrickert]

I agree with the above posts, the zero start is built into every treadmill, otherwise somebody's gonna get hurt. The thread you posted did specify what to hook up and where, but it's specific to that controller. It fools the logic in the controller to think you started from zero and dialed up quickly. While the theory may well apply to many (most?) controllers, the wiring will not necessarily be the same colors from one to the next. Markba633ca is on the right track. You've got to use the capacitor across the signal and the reference. I'm suspecting that option 1 in his picture is the most likely. You may also have to use more or less capacitor, depending on if the controller is smart enough to recognize what's a plausible (safe) rate of change to accept from the pot without hurting a treadmill user. Bigger won't be better though, as it's gonna start to compromise the response to your speed changes at some point.

If I would have looked up the wiring for the MC60 I would have figured it out. I can't believe that did not even cross my mind!! I would have had this figured out 2 days ago. Thank You And yes option one would be the correct setup. I have ordered the caps and will try this tomorrow. I will post here whether it works or not.