[benha]

[Please forgive the double-post. I don't really know if this is a Mach problem or a Gecko one, so I'm posting in both places.]

Hi, Folks.

I'm setting up my machine and I've run into a really weird problem. Hoping someone can point me in the right direction. I'll try to keep this as short as I can, but it's a complex issue:

I've got a G540 connected to a VFD using the G540's variable-voltage outputs (three wires - Hi, Lo, Signal).
The G540 should theoretically be looking for a PWM signal on Pin 14 from the computer running Mach 3.
For a long time, I was able to get the spindle to turn on and off through Mach 3, but I couldn't regulate the speed at all.
I then noticed that when I checked the "Disable Spindle Relays" box in Mach's Spindle Setup tab, the spindle stopped working. This is odd given that I don't rely on relays. The only thing that should be determining spindle speed is the output on Pin 14.
After a bit of an Ah-Ha, it occurred to me that it was possible that the CW spindle relay output might be being interpreted by the G540 as a 100% duty cycle PWM signal for controlling the Spindle. This shouldn't work since the spindle relay output is on Pin 17, but I figured "what the hell" and switched the Spindle Motor Output to Pin 17. To my amazement it started working. Sorta. The motor "pulses" around the target RPM, but at least it's now variable.

I'm really confused. Why is the G540 listening for PWM on Pin 17??? At some level, "if it works, don't ask questions," but it makes me nervous not understanding what's going on.

Also, can anyone clue me in as to what might be causing the pulsing I'm seeing in my Spindle motor at a given rev? I need to make that go away.

Thanks,
-Ben

[bmellis]

Hi,

It may assist other members of the forum to assist you if you let us know what VFD you are using, and the pins hat you've wired from the Gecko to the VFD.

The behaviour you are describing suggests to me that you may wish to check the wiring of the Gecko outputs to your VFD.
Hopefully the following helps - please keep in mind my direct experience in this arena is very limited.

>> I've got a G540 connected to a VFD using the G540's variable-voltage outputs (three wires - Hi, Lo, Signal).
This statement to me suggests that you are attempting to use the 0-10V to control the speed of the spindle.
So I'll work on that basis.

You may want to try disconnecting the VFD from the Gecko for this test, however it shouldn't really matter.
The first step that I'd try is to use Mach 3 to set the spindle motor to half speed.
This should result in 5V on the VFD output pin (5V between pin 8 (VFD Output) and pin 7 (VFD GND) if I've read the manual correctly).
From here, I'd make sure I could "see" other speeds represented correctly as well, eg. 25% results in 2.5V, 75% results in 7.5V, etc.

If you can get the correct voltages on the signal pin, then move on to the next step.

Without knowing what VFD you are using, I'll refer to a Hitachi WJ200 series VFD.
(http://www.hitachi-america.us/suppor...rt/NT3251X.pdf)

If you are getting this, then I'd check your wiring to the VFD and the configuration of the VFD.
The Hitachi VFD will support speed input via a analogue voltage reference (0-10V nominal), a current reference (4mA-20mA), and a 24V 32Khz (max) PWM train.

Based on the assumption that you are trying to use the 0-10V reference:
I'd suggest VFD +10V is connected to the H pin on the VFD, the VFD Output is connected to the O pin, and the VFD GND to the L pin.

If the wiring is to the right pins for your VFD, you may then want to then try firing up the spindle.

Apologies if you've tried the above already.

Cheers,
Brad.

[benha]

Sorry for bit clarifying earlier. I've got a Fuji Frenic-Mini VFD and a 2.2kw spindle from UgraCNC.

The G540 is connected using the screw terminal pins 7, 8 and 9 to the 10v out, common and signal terminals (11, 12 and 13) on the Frenic. (I may not have the order on those right because I'm not in front of the machine right now, but I've triple checked that the g540 pins go to the right places on the Frenic.

When the g540 sends a varied voltage the Frenic correctly spins the spindle at a regulated speed. It pulses - which is another issue to solve - but the sipped is regulated.

The problem is that the connection from the PC to the g540 is weird. It seems that the g540 is listening for PWM on pin 17 not pin 14 in the parallel cable. That doesn't jibe with anything I've read.

[benha]

Okay. So I think we're not in the same page with respect to where the problem is, but let me provide some more detail.

The spindle is an UgraCNC (Chinese) 2.2kw, water cooled model.
The VFD is a Fuji Frenic-Mini.
The Frenic's connection to the G540 uses three wires. On the Frenic these connect to terminals 11, 12 & 13. On the G540 they connect to screw terminals 7, 8 & 9 on the bottom of the unit. On the G540, 7 is ground, 8 is signal and 9 is V+. On the Frenic 11 is Common, 12 is Signal and 13 is V+ out.

Frenic 13 connects to G540 9
Frenic 12 connects to G540 8
Frenic 11 connects to G540 7

This all seems fine.

The G540 connects to the computer with a 25-pin parallel cable. Mach 3 configures how each of these 25 pins is to be used.

The CW spindle relay is, by default, on Pin 17. The PWM signal for spindle speed is, again by default, on Pin 14. Pin 14 appears from the documentation for the G540 to be the right pin to send PWM signals for it to interpret and convert to a scaled voltage to output on screw terminal 8. But that wasn't working.

After the aforementioned effort (see first post), it seemed like against all probability the G540 was listening on Parallel port Pin 17 for for PWM to derermine spindle speed, instead of the expected Pin 14. And when I configure Mach that way it does sort of work (pulsing issues being the "sort of"). This doesn't kmae any sense based on everything I've read.

I'm really trying to figure out what's going on, here.

-Ben

[adrian5]

Okay. So I think we're not in the same page with respect to where the problem is, but let me provide some more detail.

The spindle is an UgraCNC (Chinese) 2.2kw, water cooled model.
The VFD is a Fuji Frenic-Mini.
The Frenic's connection to the G540 uses three wires. On the Frenic these connect to terminals 11, 12 & 13. On the G540 they connect to screw terminals 7, 8 & 9 on the bottom of the unit. On the G540, 7 is ground, 8 is signal and 9 is V+. On the Frenic 11 is Common, 12 is Signal and 13 is V+ out.

Frenic 13 connects to G540 9
Frenic 12 connects to G540 8
Frenic 11 connects to G540 7

This all seems fine.

The G540 connects to the computer with a 25-pin parallel cable. Mach 3 configures how each of these 25 pins is to be used.

The CW spindle relay is, by default, on Pin 17. The PWM signal for spindle speed is, again by default, on Pin 14. Pin 14 appears from the documentation for the G540 to be the right pin to send PWM signals for it to interpret and convert to a scaled voltage to output on screw terminal 8. But that wasn't working.

After the aforementioned effort (see first post), it seemed like against all probability the G540 was listening on Parallel port Pin 17 for for PWM to derermine spindle speed, instead of the expected Pin 14. And when I configure Mach that way it does sort of work (pulsing issues being the "sort of"). This doesn't kmae any sense based on everything I've read.

I'm really trying to figure out what's going on, here.

-Ben

Could you please send me the settings you have on frenic mini to run this spindle?
thank you om advance