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Question number 2 of my upgrade of a cnc router I just purchased from UC100 to the Axbbe board.

The previous set up was a pin from the UC100 BOB switching a small relay which is wired to the VFD FWD run to switch it on and off, there is a seperate speed control potentiometer on the front of the electrics control panel to control the spindle speed.

I want to control the spindle speed with the 0v to 10v output on the AXBBE and have removed the potentiometer wires on the vfd and replaced with one from pin A01 and one from 5v0 out from the AXBBE and i have left the relay as it was so it is triggerred by an output pin on the AXBBE.
I can start and stop the spindle but but it only runs at the slowest rpm and i have no control over the speed within uccnc nor do i get rpm feedback there either. I have set PWM Spindle as active and matched the pin and port number to m3 and m4 relay.
I don't get any voltage across the AO1 and 5v0 wires even if if i move the spindle speed bar which has me beat?

Is it becuase the start pin isn't going directly to the vfd and through a relay first and thefore the PWM isn't working because it doesn't think the spindle is on?

I can upload my profile and vfd document if required, i thought I'd start with this first.

mark68 wrote:Question number 2 of my upgrade of a cnc router I just purchased from UC100 to the Axbbe board.

The previous set up was a pin from the UC100 BOB switching a small relay which is wired to the VFD FWD run to switch it on and off, there is a seperate speed control potentiometer on the front of the electrics control panel to control the spindle speed.

I want to control the spindle speed with the 0v to 10v output on the AXBBE and have removed the potentiometer wires on the vfd and replaced with one from pin A01 and one from 5v0 out from the AXBBE and i have left the relay as it was so it is triggerred by an output pin on the AXBBE.
I can start and stop the spindle but but it only runs at the slowest rpm and i have no control over the speed within uccnc nor do i get rpm feedback there either. I have set PWM Spindle as active and matched the pin and port number to m3 and m4 relay.
I don't get any voltage across the AO1 and 5v0 wires even if if i move the spindle speed bar which has me beat?

Is it becuase the start pin isn't going directly to the vfd and through a relay first and thefore the PWM isn't working because it doesn't think the spindle is on?

I can upload my profile and vfd document if required, i thought I'd start with this first.

The relay stays as it was. That's how the vfd fwd/rev works, just loops through COM & NO/NC. No voltage goes through it it's just a ground sink.

As for the pwm.
How have you wired it?.
Was it a 3 wire pot before?.
If so, 1st off, the 10v pin on vfd is now Ignored and not connected. That was just to power the pot.
AO1 on axbb goes to where the pot wiper was on the vfd, sometimes marked AVI.
Then the ground 5VO wire goes where the pot ground went. Sometimes marked ACOM.

If using Mach to control it, you need to go into the PLUGIN tab and assign the ANALOG OUTPUT of axbbe to the Mach PWM control.
Set spindle step pin as 0 port as 0.
Now it should send voltage through AO1.

I would also not use spindle dir on motors page for m3/m4 either. I would configure 2 outputs on the Mach inputs/outputs pages for them instead. M3 relative to the relay port/pin used on axbb.
Then set m4 to a fake port/pin then use these on the spindle page.
Makes switching m3 more reliable and less twitchy.

Hi Daz,

I've had some progress,

I can now control the spindle RPM range, I hadn't switched the Spindle PWM Analogue channel to 1. Strangely though I only had 0v to 5v output (so only half rpm) with the jumper removed from the AXBBE board which the manual says Jumper on is 0v to 5v jumper off 0v to 10v. In my case it's the opposite unless I've something else wrong.

However I don't have any RPM feedback to UCCNC, reading the odd post here I don't think that is possible as the VFD only outputs 0v to 10v analogue similiar to what is controlling the speed but the AXBBE cannot take in anaolgue return signals ?

However I don't have any RPM feedback to UCCNC

The only way to get RPM back into UCCNC is by using an encoder on the spindle. I don't believe that a VFD knows the actual RPM, just the commanded RPM.

There's a misprint on the AXBB-E or the manual regarding the jumper.

ger21 wrote:

However I don't have any RPM feedback to UCCNC

The only way to get RPM back into UCCNC is by using an encoder on the spindle. I don't believe that a VFD knows the actual RPM, just the commanded RPM.
There's a misprint on the AXBB-E or the manual regarding the jumper.

Could you get feedback using a proximity sensor reading a magnet or slot on say the spindle pulley to get rpm. Then send that back to the axbb-e as an indexer to read it?.

Not sure if you just want to read the RPM, from the manual, here's what's required for closed loop spindle control:

- The spindle speed has to be controllable with the output PWM or analog output signal.
- An incremental encoder with A and B channels has to be connected and measure the spindle speed
and the encoder resolution has to be configured.
(Note: Single Index channel feedback is currently not supported, only an incremental encoder can
be used.)

Guys can you help me with this one,

Whilst I've got the spindle speed control moving up and down, when i restart ucnc the max the slide bar goes to is 9000 rpm.

In Spindle velocity i have it set at min 3000 and max 18000 rpm is that correct? Anything I've missed here as i have had it running upto 18000 (300hz on the vfd) and then when restarting uccnc it seems to change. Yes i am applying and saving settings too.

Just checked it's related tot he pwm output it's not always going upto 10v with the slider

Is there a correlation between the min and max setting in spindle velocity, I just don't understand what is happening.

ger21 wrote:Not sure if you just want to read the RPM, from the manual, here's what's required for closed loop spindle control:

- The spindle speed has to be controllable with the output PWM or analog output signal.
- An incremental encoder with A and B channels has to be connected and measure the spindle speed
and the encoder resolution has to be configured.
(Note: Single Index channel feedback is currently not supported, only an incremental encoder can
be used.)

Ah. Reading from index not supported.
For some reason I had it in my head op was using Mach not uccnc.