Centroid Community CNC Support Forum

I don't know anything about your board but I had issues on my 728vt conversion with PM's 0-10V spindle controller board. Like you I only use the high speed pulley. I recommend playing with the numbers in the wizard and see if it helps. I had to adjust the spindle rpm to 0 rpm-4700rpm(machine is really 300-4200rpm) and more importantly botch the low speed gear ratio to .38 in the wizard. I cant explain why the changing the low speed ratio works Its a inelegant solution but It has been running perfectly for a year and gets within 20-30 rpm requested though out the whole spindle range.

I checked the as delivered PM rpm readout with a digital tach across the range. It varied less than three RPM at the most from 660 to 2880 rpm. I will check the other MDI questions in the AM. I've been up since 4:30 am, as usual and it's way past bed time.

Thank you for the ongoing help on this!

Greg wrote: ↑Wed Nov 24, 2021 11:32 pm I don't know anything about your board but I had issues on my 728vt conversion with PM's 0-10V spindle controller board. Like you I only use the high speed pulley. I recommend playing with the numbers in the wizard and see if it helps. I had to adjust the spindle rpm to 0 rpm-4700rpm(machine is really 300-4200rpm) and more importantly botch the low speed gear ratio to .38 in the wizard. I cant explain why the changing the low speed ratio works Its a inelegant solution but It has been running perfectly for a year and gets within 20-30 rpm requested though out the whole spindle range.

Thanks for this info! I was thinking that I might have to do that at some point....just experiment.

I won't be able to do much (anything) today, because....family holiday.

The KBSI had two pots for adjusting the max and min, there is also a jumper that controls if it convert voltage or current. Using a mulitmeter what is the voltage on the output of the KBSI when your calling for a low speed, Same question for hight speed,

You should also check the voltage going into the KBSI for both.

Greg

In your picture showing the 1500RPM at 100%, that is correct.
Dave_C was trying to explain this to you.
He suggested you take the spindle out of AUTO and into MAN and press and hold the + sign, the control will run up to the Max Spindle RPM programmed in the wizard.

Dave-C suggested you use MDI to control your spindle "Automatically" as you will using the G Code "S" commands
M3 S3000 should get you max RPM (near 10VDC output on Acorn Spindle Analog output) provided as you mentioned, 3000 is your max spindle RPM programmed in the Wizard.

Marty

martyscncgarage wrote: ↑Fri Nov 26, 2021 10:54 am In your picture showing the 1500RPM at 100%, that is correct.
Dave_C was trying to explain this to you.
He suggested you take the spindle out of AUTO and into MAN and press and hold the + sign, the control will run up to the Max Spindle RPM programmed in the wizard.

Dave-C suggested you use MDI to control your spindle "Automatically" as you will using the G Code "S" commands
M3 S3000 should get you max RPM (near 10VDC output on Acorn Spindle Analog output) provided as you mentioned, 3000 is your max spindle RPM programmed in the Wizard.

Marty

Here's a puzzling update.

As you can see from the image I posted initially, the Acorn is set to 0-10V (i.e. not set to 5v limit on output). I just tested min speed and max speed while using a multimeter. The Acorn board is only outputting 5V (even with it wizard set to 0-10V). That being said, at minimum manual spindle speed, 300rpm), with the PM-30 turning over 550 RPM, the KBSI is outputting .991V, while the Acorn is outputting 1.037V.

When we go to max RPM(2880 on the PM-30 readout which is checked with a digital Tach) the CNC12 screen can display ANY RPM VALUE above 1200 RPM. So 1200 RPM to 3000 RPM gives me MAX spindle speed (programmed at 3000, with an actual of 2880ish observed). Max output (in manual from 3000 rpm to 1200 rpm gives an ACORN output of 5.035V)...remembering it is set to 10V out.... The KBSI is outputting 4.982V.

When I drop the CNC12 controller down to hear the first audible decrease in speed I'm at 1185 on the touchscreen and 2770 on the PM-30. At this point the Acorn is outputting 3.973V and the KBSI is putting out an identical 3.973V to the PM Spindle.

Confused.

What is the Acorn outputting when the wires on the ADC output are disconnected? I know nothing about your KBSI board but some devices are low impedance and pull the Acorn output down from 10V.

tblough wrote: ↑Sat Nov 27, 2021 3:22 pm What is the Acorn outputting when the wires on the ADC output are disconnected? I know nothing about your KBSI board but some devices are low impedance and pull the Acorn output down from 10V.

I'll try to check in a few. The KBSI is a signal isolator primarily. It should not pull down the signal. It converts the signal.

Please, ALWAYS post a fresh report when asking for help. It has all your machine parameters in it.

Have you run the Basic Acorn Spindle bench test?
This might help:


Need to make sure Acorn spindle analog output is functioning correctly first.

Marty

martyscncgarage wrote: ↑Sat Nov 27, 2021 3:47 pm Please, ALWAYS post a fresh report when asking for help. It has all your machine parameters in it.

Have you run the Basic Acorn Spindle bench test?
This might help:


Need to make sure Acorn spindle analog output is functioning correctly first.

Marty

The report is attached to post #1