Thank you for the schematic. My threadmill's MC-60 was fried during a thunderstorm. The MOV was obviously exploded into ashes. D3 and D4 diodes were shorted and the copper trace that tied their cathodes together was burnt open. I replaced the MOV with a bigger one and the diodes (originally IN4007) to bigger 1N5400 3A ones which I had lying around. The treadmill works now.

 

Question for you experts: Using the MC-60 for a drill press (with DC treadmill motor). Works great, except for the start. Have to turn down the speed control to 0 and then ramp it back up again. Seen some schematic with a soft start circuit but it was hanging off the side so don't know what to do with it. Any recommendation from anyone how I can add a push button to the circuitry to initiate the start? Might be more than a push button . Maybe RC combination where button pull down the voltage to 0V and then slowly ramps it up to what is needed at the pot?
I suspect this is a safety feature of the MC-60. Again, I don't want to change the speed settings on the pot. When power is applied, I want to motor so slowly ramp up to that speed.

Thanks a bunch!

 

Just joined the forum, so pardon my belated response to your question.

If you add a normally closed pushbutton between the pot wiper and the "W" terminal of the controller, and briefly open the circuit, the motor will ramp up to the speed previously set on the pot.

I added a treadmill motor and MC-60 to my drill press a year or so ago. Was fortunate to find a suitable pot with a built in pull-on, push-off switch, so I wired this in. The original 110V on-off switch on the drill press controls input power to the MC-60 (as well as a light and a tach). The switched pot controls motor start/stop and speed.

== == == == == == == == == == == == == == ==

Now a question for the forum ... When opening the aforementioned switch to turn off the motor, it takes what I think is WAY too long for the motor/flywheel to spin down and stop. Just tried adding a brake band to the flywheel to get things stopped faster. Lo and behold ... didn't work! It appears the controller is following a pre-programmed speed ramp-down! As soon as I release the brake band, the motor comes back up to speed (maybe a bit slower than originally) and winds down slowly.

What part of the circuit is producing this speed ramp-down????? My best guess at the moment is that C10 and associated circuitry are involved. Would adjusting R31 reduce the ramp-down time? Enquiring minds want to know.

Thanks!

 

So you are using the original flywheel?
This is normally removed for just about any other typical usage the motor is put to, your application would be included, some are left hand thread, so this has to be detected in order to remove.
Max.

 

So you are using the original flywheel?
This is normally removed for just about any other typical usage the motor is put to, your application would be included, some are left hand thread, so this has to be detected in order to remove.
Max.

Yes, I'm using the flywheel. I found that the simplest solution to adapting the motor to the drill press was to bore out the rear DP step pulley to fit over the multi-groove extension of the flywheel. There was no issue with the thread handedness.

What I found out yesterday was that the flywheel is NOT what's causing the speed to ramp down slowly when the pot wiper is interrupted or when the pot turned down to zero. I can actually stop the flywheel, but when I let go, the motor winds up again, then continues with a slow ramp-down. This HAS to be something in the control circuit of the MC-60. I'm using an unmodified MC-60 and hoping to learn what to "cut out" to get rid of the ramp-down.

- John

 

This may be a characteristic of the MC-60, being T.M. oriented, although I have not heard of it, I have always used the KB series of DC motor controllers, or self designed ones with T.M. motors.
Also removed the Flywheel.
Max.

 

This may be a characteristic of the MC-60, being T.M. oriented,

Yup. That's why I posted my question on this (MC-60) thread. I'm hoping somebody who's previously posted here is familiar with that part of the circuit.

 

The flywheel will still be an issue on the deceleration problem, if you cut power it is going to take longer to slow to a stop.
Max.

 

The flywheel will still be an issue on the deceleration problem, if you cut power it is going to take longer to slow to a stop.
Max.

As I've tried to explain twice now, this whole issue showed itself when I tried to add a brake band to the flywheel. Quoting from my first post:

"Just tried adding a brake band to the flywheel to get things stopped faster. Lo and behold ... didn't work! It appears the controller is following a pre-programmed speed ramp-down! As soon as I release the brake band, the motor comes back up to speed (maybe a bit slower than originally) and winds down slowly."

The flywheel will NOT be a problem, once somebody who knows what they're talking about answers my original question about the MC-60's ramp-down circuitry and how to defeat it. You seem absolutely obsessed with the flywheel, but please rest assured, that is (or will be) a total non-issue.

 

If anyone wants a copy of the Eagle CAD file or datasheets, let me know. Thanks in advance.

Hi guys.

Is the Eagle file for the MC-60 still available? If so, where is it?

Thanks
Pat

 

Guess this thread is still active, & about MC60 controller - great! 'Cause I have a simple (for someone) question:

I have assembled a controller to run a treadmill motor at slow speed, forward or reverse (for a table lift mechanism). It uses an Arduino to control an MC60. It works, but when the motor is stopped from a running state, it kicks momentarily in the opposite direction. A simplified schematic of the wiring is attached.

The Arduino uses a relay to set the motor direction, and then another relay to run/stop the motor. The MC60 speed control is wired with a voltage divider (including a 1K pot to provide limited speed adjustment). The run relay contacts open to allow the W terminal to rise to the voltage determined by the voltage divider. The motor runs at the desired speed. The contacts close to set the W terminal to ground, causing the motor to stop. This is when the motor stops, and momentarily kicks in the opposite direction.

I supposed this is due to collapsing field in the motor, and maybe I should wire in a flyback diode (as shown in the schematic, but is not in the circuit at this time), but I am not clear on this:

• Shouldn't safe induction collapse already be provided for in the MC60?
• This is a 130 vdc 2.75 hp motor. What would be an appropriate diode to use - if that is the thing to do?

Thanks for any help...

 

I suspect your problem is because the motor is stopped prematurely by the stop contact the decel circuit is still active when this occurs, at this point does the reverse relay also drop out?
Max.

 

I suspect your problem is because the motor is stopped prematurely by the stop contact the decel circuit is still active when this occurs, at this point does the reverse relay also drop out?
Max.

Max - you nailed it! After your message, I went back and saw that it was indeed the direction relay dropping out before drive voltage had decayed. I can fix that with the Arduino program.

Thank you very much, sir.

 

Incidentally if you need to defeat the fact that the pot input has to be at zero at power up, the Resistor R19 15k next to the centre pot terminal has to be removed.
Max.

 

Incidentally if you need to defeat the fact that the pot input has to be at zero at power up, the Resistor R19 15k next to the centre pot terminal has to be removed.
Max.

Thanks for the tip. First, sorry for the delay - I have had a surprise hiccup of my heart, and was off having it checked out. Distracted me for a while.

The matter of having to return to 0 before starting up is an annoyance. But, I did handle that with the Arduino controlling a voltage divider through relays for this project. Still need to have a delay between forward and reverse which the Arduino is also handling, so I'll stick with it for now.

Speaking of that delay, there seems to be an additional delay separate from the Arduino-imposed delay. Does the MC60 have a built-in start up delay?

 

Speaking of that delay, there seems to be an additional delay separate from the Arduino-imposed delay. Does the MC60 have a built-in start up delay?

Yes, both start up and stopping.
I have not yet found the answer to defeat it.
Max.

 

A further question on the MC60.

Background:
I noticed in my project - [using a treadmill motor to drive a scissors jack to lift a 150 lb. table] - that the mechanism was unable to start the lift. With jack at the bottom of it's range (minimum mechanical advantage), and weight to lift = ~75 lb, motor stalls. With an external assist, the motor runs, and after a couple inches of rise (once jack provides sufficient mechanical advantage), mechanism runs unassisted and readily lifts the total 150 lb.

Question:
I'm not sure if this is a function of the motor, or perhaps the MC60. The motor is rated at 2 hp treadmill duty, and 1.75 hp continuous duty. I thought this motor would be overkill for this applicaton, so was surprised that I had to build in additional help (springs) to get the lift started. I run it only on a preset low speed.

So is the MC60 the limiting factor- would a beefier motor controller be the better answer? Or is this the expected capability of this motor?

Thanks,
Dennis

 

It seems clear for this application that you require a reduction of some kind, pulley or gearbox to obtain required torque.
Max.

 

It seems clear for this application that you require a reduction of some kind, pulley or gearbox to obtain required torque.
Max.

I'll take that as the correct answer. I think maybe that jack probably adds load at the bottom end of travel. For now, I have got it working by using springs to assist the lift - because I couldn't find a practical way to obtain mechanical devices that would fit into this application.

Thanks again for your quick response.

 

gpaCook:
Speaking of that delay, there seems to be an additional delay separate from the Arduino-imposed delay. Does the MC60 have a built-in start up delay?

Max Headroom:
Yes, both start up and stopping.
I have not yet found the answer to defeat it.
Max.

Durn it Max, I sure wish you'd said that around October of last year, when I was asking essentially the same question. Woulda kept me from getting aggravated with you.

- John