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Clearpath Servo Control, Manual Lathe Spindle.

Rauce

Ultra Member
So I stumbled upon a deal on a used clearpath servo motor. Model CPM-MCVC-N1433S-RLN. Going to go pick it up later this week.

This motor will deliver 2.3hp continuous and 6.7hp peak running off single phase 230v power. Comes with a regenerative resistor unit as well for increased braking capability.

I plan to use this in my hendey lathe in place of the VFD and 3hp 1750rpm AC motor that I got with the machine.

I’ve been studying the control modes for the motor and there are two modes that make sense for use in a lathe.

The first is what they call manual velocity control. This would have an on/off switch to enable or disable motor and speed is controlled with a quadrature encoder. Direction can be controlled but only as part of the encoder signal. So turn the encoder clockwise and the motor turns one way or turn the encoder ccw and the motor turns the other way. It has the option to recall the last setting when enabled or to always start at 0rpm.


The second applicable mode is Follow Digital Velocity Command. In this mode Enable and Disable works the same way. Where it differs is that speed is controlled by a PWM or Fequency signal on one input and direction of rotation is controlled on another.


While the manual velocity control mode would work it doesn’t seem ideal to me. I’d much prefer to be able control direction of rotation seperate from speed and be able to set a speed with the motor disabled.

The follow digital velocity command mode would deliver what I want but the execution is the part I’m unsure of. I would need a way to deliver either a PWM or frequency signal and a display to see what I’ve set it to.

I have a feeling that this is something that can be done with an arduino? In a perfect world I would be able to display the theoretical spindle speed on the display for the frequency generating device. This would be calculated by the relationship of frequency to motor speed and then to spindle speed.
 

Arbutus

Super User
Premium Member
Easy to do with Arduino or Teensy. I use the Clearpath servos for my mill. The spindle motor is an MCVC which is controlled by a digital direction and a digital PWM speed signal.

One thing to be aware of is that the Clearpath system does not expose the internal encoder signal, so there's no way to pick that up to use for spindle:feed synchronization. If you need that, you will need an external encoder (600-1200PPR) and manage the spindle speed through the Teensy. With this setup it is also easy to show the digital RPM/Direction on an LCD display, driven by the Teensy.

Don
 

Rauce

Ultra Member
Easy to do with Arduino or Teensy. I use the Clearpath servos for my mill. The spindle motor is an MCVC which is controlled by a digital direction and a digital PWM speed signal.

One thing to be aware of is that the Clearpath system does not expose the internal encoder signal, so there's no way to pick that up to use for spindle:feed synchronization. If you need that, you will need an external encoder (600-1200PPR) and manage the spindle speed through the Teensy. With this setup it is also easy to show the digital RPM/Direction on an LCD display, driven by the Teensy.

Don

I don’t think I’ll need encoder output from the motor for anything. Not planning an ELS or anything like that.

For direction I’d like to just use a simple switch. Probably a switch with an LED for the enable/disable.

For the PWM signal I’d just like a display so I can set it while the motor is off and that way it will ramp up to the selected speed when it’s started. If that display could include the theoretical spindle rpm (different than the motor RPM because of the pulleys ) instead of just the 0-100 of the PWM signal that would be even better.

When you say easy what do you mean by that? I’ve never messed with anything like or done any coding.
 
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Maker Mike

Active Member
Premium Member
I just bought the CPM-SDHP-N1433A-ELN and a clearcore motion controller for the milling machine spindle motor. I'll be honest I have no idea how to do the C++ programming. It has an arduino wrapper, but that doesn't help much either since I have never programmed an arduino. I bought a potentiometer for speed adjustment, which I think will work if wired a programmed correctly. Guess I have some learning to do. They do have a library of examples, which will be a starting point.
 

Rauce

Ultra Member
I just bought the CPM-SDHP-N1433A-ELN and a clearcore motion controller for the milling machine spindle motor. I'll be honest I have no idea how to do the C++ programming. It has an arduino wrapper, but that doesn't help much either since I have never programmed an arduino. I bought a potentiometer for speed adjustment, which I think will work if wired a programmed correctly. Guess I have some learning to do. They do have a library of examples, which will be a starting point.
That’s the same size and power as mine but with step and direction capability.

If you want a simple control look at the manual velocity control mode I mentioned above. No programming required just settings in the clearpath software and a switch and encoder. A potentiometer won’t work since it’s an analog signal.
 

Maker Mike

Active Member
Premium Member
I think those mode choices are only for the MCVC. The engineer at clearpath talked me into to it when I said that sure someday I would like to do rigid tapping. I'll figure it out and will be a better maker as a result.
 

Teknic_Servo

New Member
Hello Rauce,

The control inputs of the ClearPath MC and SD series are compatible with digital signals between 5-24 VDC. So yes, the I/O pins (provided they drive 5-24 Vdc) on almost any microcontroller (including an Arduino) could be programmed to handle your application objectives. You're probably aware that most microcontrollers use C++ or some derivative of this language, so having some background in this area would be helpful.

You could also look at our Arduino-compatible microcontroller, called ClearCore. We created an Arduino software wrapper so ClearCore shows up as an Arduino-compatible controller within the Arduino IDE "Board Manager". Note that we currently support the Arduino 1.8x IDE and will be releasing a new version compatible for the Arduino 2.x IDE version in a few months.

ClearCore's software libraries are open and you can download the source code for viewing from the downloads page on our website (sorry, as a new user, we're not allowed to post links). If you decide to install this software, I recommend that you review the ClearCore software examples. There are multiple examples that highlight how to control the ClearPath motors in the operating modes you described, as well as examples that could be used to display the ClearPath's commanded velocity on a 4-line LCD screen. If you prefer something more sophisticated, there are also two examples for a touchscreen HMI display.

I hope this helps. If you have any further questions, please feel free to submit a contact request on Teknic's website or give us a call at 585-784-7454.

-Abe A - Teknic Applications Engineer
 
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