Hi all,

Great info! Thanks to everyone who has contributed so far. I've got a few questions:

I am a novice when it comes to electronics, however I am working on a treadmill project and using and off the shelf MC-60 controller which as worked well thus far. I am pushing a Turdan 90V 30A motor.

Goals:
1. Trying to figure out a way to use Arduino to control speed on the MC-60.
2. I would like to buy large quantities of controllers straight from a manufacturer and thought about reverse engineering the MC-60 as a starting point.

Questions:
1. The 12V potentiometer circuit on the MC-60 is problematic as most digital pots are 0-5V. Is there a best way to interface the MC-60 with Arduino? I am currently using a mechanical pot which is suuuuper lame. I saw that gpaCook was able to figure something out and get it working. I am trying to get a sense of what on the MC-60 pcb can be modified in production to allow for a 0-5V digital pot to be used? Or maybe a PWM signal? Maybe there is another controller out there that will be more suited for my needs?
2. This is my first pcb spec. Is a schematic like the fantastic example mpweir provided the only thing a manufacturer needs to build a pcb? Or should I get into Eagle and generate a gerber file?

Thanks in advance for your help everyone! And once again, thanks for the help in the form of detailed replies to this thread.

- John

 

If looking for a future replacement, I would advise looking at the PWM version of controller, for e.g., the MC2100 is not only PWM motor control, but it is PWM (20Hz) command, instead of a Pot.
I built a small board with the stop/start/Pot feature and out put the required 20Hz PWM command signal.
I used a pot for the Pic 12f input and P.B.'s etc.
The MC2100 has ramp up automatically, IOW, if you restart and the Pot is at some previous speed control point, the motor simply ramps up to the previous set point.
Also Super quiet control with PWM, no need for a choke.
You could also look at your own PWM controller to do the same, but include bi-directional PWM output.
I have designed around Tahmids blog here
Max.

 

Thanks Max! I just read up on the MC2100 here. Man, you guys are operating on so many levels higher than my comprehension!

Ok, so in terms of "off the shelf", the MC2100 uses PWM instead of SCR for driving the motor AND it allows PWM signal for speed control? So I could just feed it an Arduino derived PWM signal 0-5V and that's it? That seems like a pretty good option for prototyping.

However, I was also seeing reference to the incline functionality which is more than I need. I was thinking that my next step beyond prototyping would be to have a PCB manufacturer in China provide me with some samples to test for production. I wonder if sending them a MC2100 schematic and asking them to omit the circuitry pertaining to incline would be enough to get the ball rolling? However, I also know the pitfalls of overseas manufacturing... hmm...

Thanks,
John




. At this stage, I simply need a controller that will have the same perform

 

I'm not sure if that would succeed as unlike the MC-60, the MC2100 has a micro on board that receives the low freq. PWM signal and processes it, whereas the MC60 is purely digital IC's etc.
Max.

 

I hate when contributors respond negatively, but I'm going to do so and tell you why.

Remember, as I wrote in my document, "ground" in the circuit is a 170 volt AC signal with respect to any other "ground" you might have in external circuitry. If you don't provide the necessary isolation, it would be very easy to blow up (literally) the Arduino and the attached computer you're using to program it. If you have the Arduino programmed, and then disconnect from your programming environment and reconnect it strictly into the MC-60, that could work, but you still need to have appropriate isolation between the system and any operational inputs and outputs (switches, etc., or external digital signals). It's doable, but presents serious challenges to do it safely.

I took a quick look at the MC2100 link above, and it might be a better candidate. I see they've separated the line-connected bridge and power circuits from the low voltage control circuits and used optical isolation to couple between them. That's one approach you'd have to understand and implement to use the MC-60. My advice is to ignore the MC-60.

 

I hate when contributors respond negatively,
.

To which post(s) are you referring?
Max.

 

Been on a lot of forums of the years... I wish more contributors are as "negative" as you mpweir!!!

Thank you very much Max and mpweir for your feedback and suggestions. Is there any other treadmill controller, or other non-treadmill motor controller that you guys could recommend? Or know anyone who builds these kinds of things?

-s

 

One of the main producers of these types of DC motor controllers is KB Controls for both SCR bridge type and PWM https://www.kb-controls.com/
The other source is such as Ebay for servo motor controllers from A-M-C, Copley etc.
Max.

 

Thanks Max!

 

To which post(s) are you referring?
Max.

No one in particular, Max, certainly none of yours: just on some sites responders can be very discouraging, without justification. I try to be helpful.
MPW

 

hello

on the mc-65 \ 66 there is a dioed D11 \ i am not sure if it's a diode or diac or ntc .

there board mark D11 , does any one know what it is , there is not marking on it

thank you

 

This seems to be THE mc60 forum thats lasted 8 years !!!. Anyways ... Trying to defeat the ramp down circuit.
Someone said that removing c104 would give faster response. Problem is, I can't find a c104.

 

Do not have a record of one with C104, there were at least 3 ver of the MC-60.
Have you done the defeat for the neccessity to zero the pot before start?
Also are you using the motor with the flywheel still fitted?
Max.

 

Do not have a record of one with C104, there were at least 3 ver of the MC-60.
Have you done the defeat for the neccessity to zero the pot before start?
Also are you using the motor with the flywheel still fitted?
Max.

Hey Max !!!

I use these controllers all the time and have never noticed the ramp down due to motors always taking a bit
to come to a stop. But I am using a small motor (coke can size) on a sewing machine and when I let up on
the pedal pot, it runs for a few seconds. For safety's sake I need it to stop.

Oh, and I did do the R17? cut for the safe start issue.

I do have some other controllers that behave a bit better but they wont fit in the base of the sewing machine.

Here is the post from this thread that I am referring too. Re-reading his post, he at first says c4 then says c104.
Would removing C4 do what I want ?



mpweir
Joined May 11, 2018 6
Dec 2, 2018

• #52

I believe RebelJD has the right idea. The phrase "soft start" means to me bringing the speed up slowly, which I think is strictly a result of C4 and the associated resistances which provide current to it. I consider U2A a "power up interlock" which prevents the motor running until the speed control has been returned to zero. It's not a bad idea to leave it functional, but I would lift R27 to disable the interlock. Speed changes will still be slow. Removing C104 or disconnecting one of its leads should allow quick response to the speed control and, incidentally, upon powering up. As I understand the circuit, lifting R19 would eliminate the "anticipatory" function of U1C, probably leaving the controller much less responsive to motor load. I encourage RebelJD to singly make these changes and report the results!

 

What is the nature of the sewing-M motor? Maybe the over-run is due to the inertia of the load attached to the motor?
If so, it can occur even though the voltage has been removed.
In which case, some kind of dynamic or mechanical braking could be needed?
Max.

 

Hey Max !!!

I use these controllers all the time and have never noticed the ramp down due to motors always taking a bit
to come to a stop. But I am using a small motor (coke can size) on a sewing machine and when I let up on
the pedal pot, it runs for a few seconds. For safety's sake I need it to stop.

Oh, and I did do the R17? cut for the safe start issue.

I do have some other controllers that behave a bit better but they wont fit in the base of the sewing machine.

Here is the post from this thread that I am referring too. Re-reading his post, he at first says c4 then says c104.
Would removing C4 do what I want ?



mpweir
Joined May 11, 2018 6
Dec 2, 2018

• #52

I believe RebelJD has the right idea. The phrase "soft start" means to me bringing the speed up slowly, which I think is strictly a result of C4 and the associated resistances which provide current to it. I consider U2A a "power up interlock" which prevents the motor running until the speed control has been returned to zero. It's not a bad idea to leave it functional, but I would lift R27 to disable the interlock. Speed changes will still be slow. Removing C104 or disconnecting one of its leads should allow quick response to the speed control and, incidentally, upon powering up. As I understand the circuit, lifting R19 would eliminate the "anticipatory" function of U1C, probably leaving the controller much less responsive to motor load. I encourage RebelJD to singly make these changes and report the results!

My mistake: I meant C104, not C4. Some of my reference designators match the board revision I had in hand; others I made up to be able to refer to them in the text. C104 is the one shorted by ground by Q7, driven by U2A, in the power up interlock circuit.
MPW

 

My mistake: I meant C104, not C4. Some of my reference designators match the board revision I had in hand; others I made up to be able to refer to them in the text. C104 is the one shorted by ground by Q7, driven by U2A, in the power up interlock circuit.
MPW

Thanks Mpweir, but that begs the question, where on the board is C104 ? And am I/you correct that this
will make the speed changes quicker ?

And Max, there is a pretty good load on the motor and its pretty little so there isn't much coasting.

 

Max, there is a pretty good load on the motor and its pretty little so there isn't much coasting.

It is also the size of the load that decides the coasting time, so this could be the reason, you could test-short out the motor leads as soon as the power is removed and see if it causes dynamic braking on those few seconds you mentioned.
It appears the C104 that mpweir refers to is a 22uf electrolytic across Q7.I have a cap marked C14 next to it?
Max.

 

Thanks Mpweir, but that begs the question, where on the board is C104 ? And am I/you correct that this
will make the speed changes quicker ?

And Max, there is a pretty good load on the motor and its pretty little so there isn't much coasting.

Don't know where it is. Mine is now housed inside my toolpost grinder control box. It's a 22 microfarad, just as you surmised. I could have been mistaken in reading the reference designator off the board. I predict its removal will make speed changes quicker (perhaps even unstable, and subject of course to load inertia), but probably won't eliminate the power up interlock.

 

Thanks much for the schematic and functional description Mpwier. This is quite a thread ... I am in awe.

Can anyone let me know what MOV and high voltage cap are used on the AC-input power conditioning section of the MC-60 ? The ones of interest are V101 and CX101 on Mpwier's schematic ( MOV1 and C16 on my MC-60 ).

I'm fixing my MC for continued use in a treadmill, and want to go with properly rated replacements.

Mine took a hit during a storm, and those two guys got cooked beyond recognition.