speed calibration between mach3 and 2.2kw water cooled vfd spindle

I have a Chinese water cooled 2.2kw spindle. I am using mach3 to control it. It's in an cncrouterparts 48x24 cnc I put together.

I've tried all the parameter settings and can get it to work, sort of. Mach3 can turn on and off the spindle. The spindle speed in mach 3 shows a similar (within a few hundred) rpm at low speeds with the vfd. however, at higher speeds it's off by as much as 5k.

Example
mach 3 says 10387 vfd says 10660
mach 3 says 11985 vfd sats 14380
mach 3 says 13583 vfd says 18050
mach 3 says 15181 vfd says 21782

I am using the spindle cwf5 button to start and stop for this example. I am using the +/- key to control spindle speed

I've read a lot of forum articles and not sure where to go with this. Is it my pd settings on the vfd or a pully / calibration issue in mach3

What method are you using to control the speed, and what hardware?
0-10v?

The hardware is a leadshine mx4660

I am using a relay to turn on and off the spindle

speed is controlled by 0-10v off leadshine

Is that what you were asking?
I really appreciate the help. I

I think it's just nonlinear. Check out this post on how to upgrade to a Modbus control, assuming your VFD supports it.

http://www.cnczone.com/forums/chines...ml#post1921890

Crappy PWM output => crappy rpm control.

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Originally Posted by hiposner

Example
mach 3 says 10387 vfd says 10660
mach 3 says 11985 vfd sats 14380
mach 3 says 13583 vfd says 18050
mach 3 says 15181 vfd says 21782

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This is typical for a crappy D/A controller. You have to options, one is to get a HIGH quality PWM unit, the other is to use Modbus. Of course, that assuming your VFD can handle Modbus. If it can't then maybe you can find some plugin to control via RS485. Maybe your PWM module is faulty because your values are VERY far off.

You need to measure the analog voltage coming out of the MX4660.
At 12,000 RPM, it should be 5V.
At 24,000 RPM, it should be 10V.

Measure the voltages and see what they are. That will dictate what to do next.

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Originally Posted by ger21

You need to measure the analog voltage coming out of the MX4660.
At 12,000 RPM, it should be 5V.
At 24,000 RPM, it should be 10V.

Measure the voltages and see what they are. That will dictate what to do next.

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Hi Ger,

I made this same assumption when I was troubleshooting. Your 5V will could vary based on your min rpm, if your min RPM is set to 6000 than 5V = 9000.

No, it shouldn't. Your VFD doesn't know what the minimum speed in your control software is. When using 0-10V, 0V = 0rpm, and 10V = max rpm.

If you set your minimum speed to 6000, you should see 2.5V. If you program S2000, it should still output 2.5V, which would be the minimum speed.

Note that there are settings in the control software that can alter the output. In UCCNC, you can use the min and max PWM duty to vary the voltage.
Because I couldn't get 10V from me speed control, I set the PWM max duty to 50%, which gave me a 0-5V signal. At 12,000 rpm, I always got 2.5V, even though my minimum speed was set to 8000 rpm.

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Originally Posted by Dan911

Hi Ger,

I made this same assumption when I was troubleshooting. Your 5V will could vary based on your min rpm, if your min RPM is set to 6000 than 5V = 9000.

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No. 5V should still be 12k RPM because it is over the minimum 6k RPM according to your example. The VFD should only make sure that the RPM never gets below 6k, so 2.5V = 6k RPM and 2V should also be 6k RPM but 5V should be 12k RPM. At least this is the way my VFD works.

When I was trouble shooting my cncrouterparts electronic kit RPM erratic behavior that turned out to be a loose connection to smoothie board I was getting 5v at around 15000 rpm. It was explained to me it was due to my 8000 rpm min setting. Maybe I misinterpreted or not remembering correctly but I intend to check on a day I'm at shop. What I do remember for sure because it was the first thing I did was set RPM to 12000 in Mach3 expecting 5V and it was a couple of volts less and why I called.

Dan

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I was getting 5v at around 15000 rpm

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Then your PWM signal was incorrect, or the speed control was not working properly.
Voltage is always proportional to rpm, and should be the first thing to check.
If the voltage is correct, then you would check your VFD settings to see why the RPM does not match the voltage.

I am embarrassed to make this post, but I want to resolve the issue publicly so somebody else as stupid as me doesn't make the same mistake.

The answer was pd70 = 0

I had followed some post with all the settings for the vfd without really paying too much attention after the first 20 or so "pd's"
When the first reply asked me what was controlling the vfd I realized that it was 1-10 volts (pd=0) not 1-5 volts (pd=1) as I had programmed.

It's still only accurate to about 400 rpm, but it's much more consistent and I can live with 400 rpm.

Thanks all. Your time and help was spectacular. I hope to be able to help others in the future.

Hillel

Quote:

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Originally Posted by ger21

Then your PWM signal was incorrect, or the speed control was not working properly.
Voltage is always proportional to rpm, and should be the first thing to check.
If the voltage is correct, then you would check your VFD settings to see why the RPM does not match the voltage.

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My experience with this is only what I posted above, VFD/spindle, electronics kit was all purchased plug and play.
Loaded supplied .xml and everything been working fine other than hip-cup I mentioned almost a year ago.

I would think between the settings of Smoothie board and VFD any configuration is possible, also logically thinking lowering the margin between the voltage could mean a more consistent rpm. This is just a thought not based on fact.

I will check it out this week and report findings back since you put the bug in my ear...lol

Dan

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No, it shouldn't. Your VFD doesn't know what the minimum speed in your control software is. When using 0-10V, 0V = 0rpm, and 10V = max rpm.

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Snip below taken from the Huanyang Manual, doesn't theses parameters set 0V and 10V?

Attachment 388726

No.
0V = 0Hz, and 10V = 400Hz (PD072 value or max rpm)
The Huanyang has no way to adjust the relationship between Hz and voltage.
That's why I had to use 0-5V, because I couldn't get 400Hz with only ±8V from my speed control board.

A better VFD should allow you to say that 8V = 400Hz, so that you can match the RPM to the analog voltage.

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Originally Posted by ger21

No.
0V = 0Hz, and 10V = 400Hz (PD072 value or max rpm)
The Huanyang has no way to adjust the relationship between Hz and voltage.
That's why I had to use 0-5V, because I couldn't get 400Hz with only ±8V from my speed control board.

A better VFD should allow you to say that 8V = 400Hz, so that you can match the RPM to the analog voltage.

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Ok,Thanks.

I am certain of what I posted previously, so maybe the Delta/smoothieboard has a setting to manipulate the 0-10 volts HZ. Shop very busy and my brother will go nuts if I stop production and start tinkering, maybe tomorrow.

Dan

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Originally Posted by Dan911

Ok,Thanks.

I am certain of what I posted previously, so maybe the Delta/smoothieboard has a setting to manipulate the 0-10 volts HZ. Shop very busy and my brother will go nuts if I stop production and start tinkering, maybe tomorrow.

Dan

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Yes some of the good breakout boards have a pot to adjust the output of the 0-10v so you can get it to work within +/- 2 RPM, and some tweak's you can do in Mach3 also can help mainly the pulley ratio

You can also add the remote pot to the VFD and adjust the RPM to get them close and just leave it at that setting, so by doing this you can correct the RPM if they are way off where they should be, it's just like what you can do in some other VFD Drives that have Parameters to do the settings

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I am certain of what I posted previously,

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I'm pretty sure that what I posted is correct too. :)

I'm surprised more do not use the serial plug in for Mach. If Huanyang, that is.
No setting up of external inputs or analogue settings.
Al.