UC300ETH-5LPT + C10S VFD PWM Control

[moparx12]

Hi all,

I have been trudging through the changeover from the chinese USB Leafboy77 motion controller/BOB and Mach 3 to the combo in the description with UCCNC software.

I have gotten all of the axes to work (they sound better than I ever thought the would, btw)! I am having problems with what I think is a somewhat unique VFD. I have a Sunfar model E300, single phase 3.7 KW. The datasheet for it can be found here: [url]http://prom-electric.ru/media/chastotnii-preobrazovatel-sunfar-e300-manual-en.pdf
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If you look on page 13 of that PDF, you can see a schematic for how the VFD panel should be hooked up. Apparently, the setup that works on the leafboy board does NOT work with the UC300ETH. I don't have an o-scope so I am not sure how to tell what the signal is coming out of the leafboy or the signal coming out of the UC300ETH for that matter.

On the BOB, port 2, I have tried the following connections:

pin 14 BOB, FWD terminal on VFD
Pin 1 BOB, AI terminal on VFD
GND BOB, CM terminal on VFD

There is a resistor of value I don't know tied to the AI terminal at the VFD on one end and to the 10v terminal on the other.

In the UCCNC settings, I have the PWM base frequency set to 3125Hz, as it was when I was using the leafboy. I have PWM enabled, with a 0-100% duty cycle range. I also have the spindle relay output ENABLED, set to ACTIVE LOW on pin 14, port 2. These settings will turn the spindle ON with an M3 command, and I also learned I can adjust the speed as well, but the range is truncated significantly from the 1-18000 rpm I am going for. If i set M3 S18000, for example, the spindle turns on but only something less than 1k RPM. if I set S1000, the spindle just barely creeps at maybe 10 rpm or so.

I don't understand how the PWM output at Pin 1 on the BOB somehow creates an analog input of 0-10v at the VFD. I assume that there is some circuitry inside of it that allows that to happen. If someone could take a look at this and help me find the solution quicker I certainly would be VERY appreciative.

Thanks!

[ger21]

Try setting the base frequency to 100Jz, and see if that makes any difference. I wouldn't try to run a chinese spindle at 1000 rpm, as you can burn them up quickly doing that. I'd set the PWM min to maybe 30%, which should be a bit less than 6000 rpm.

My guess, and from what I read somewhere else, is that the speed control implementation used by your Leafboy control was at best a "hack". It's not that you're VFD is different from others, as it still accepts a 0-10V analog input.

If it were me, I'd get a speed control board to convert the PWM to 0-10V, like everyone else uses.

If you can't get that to work, then I'd get a Huanyang VFD for $135.
Keep in mind that you can control the Huanyang with a free UCCNC plugin, and an $8 USB > RS485 converter. Links to both are on my website.

[moparx12]

Well i tried 100 hz and that did not help at all. Made the spindle oscillate its speed.

What speed control board is everyone using?

[cncdrive]

The 3125Hz is probably too fast for your BOB. For that to work you would need a cutoff freq. min. of at least 312500Hz if you would expect at least 100 different speed points to work.
The 100Hz is probably too slow for the VFD's input filter, so it measures into the PWM low and high cycles only is why the speed is fluctating.
I advice to try some mid-values of frequencies.

You may also try the UC300ETH's analog port, it has a analog outputs and you can attach the spindle PWM to that analog output with the I/O setup page"Spindle PWM -> analog ch."setting and then you get an analog 0-10V on the selected analog channel in the analog port of the UC300ETH-5LPT.

[moparx12]

Thank you. I will try some other values. I will also try the analog port like you say! I am not using either of them at the moment.

[moparx12]

Awesome! The anolog pin works! Fully functioning spindle now, thanks guys.

[ger21]

Awesome! The anolog pin works! Fully functioning spindle now, thanks guys.

Forgot all about the analog outputs.

[moparx12]

One more little problem. When I cut power to the machine, spi dle already off and stopped, the spindle spins up and slowly and then spins to a stop. Ill try unhooking the resistor connecting the 10v to the pwm pin on the vfd.

[ger21]

Not sure how you have it wired now, but you shouldn't be using the PWM pin and wire anymore, and that resistor should not be there either. You should just have the analog output to the spindle.
However, you also should have a relay starting and stopping the spindle, which I don't think you have? That may be what the problem is?

[moparx12]

I do have a spindle relay, but it could be that I have it hooked up wrong. The resistor is on the VFD terminals themselves, which is why I didn't remove it (didn't have to to get it working). I'm at work now but will look at it again later. all I did with hardware was move the PWM wire from digital pin 1 on the BOB to Analog Output 1 on the BOB. I had a little 2 pin female connector sitting around that fit perfectly in that port at pins 6 and 7 (or 5 and 6, can't remember).