Tuning and Calibrating Spindle Speed with a VFD (inverter)

[cnckeith]

copied this from one of Gary's post.

Gary says....
My method for calibrating spindles on Router machines:
Install a 0.1mfd CAP
Set Min RPM to 0
If you desire a minimum speed, set a VFD parm to enable that, not Acorn Wizard
Set Max RPM to spindle rated speed (usually 18k or 24k)\
Then do a test at 25%, 50% 75% and 100% via MDI. For each, write down the commanded vs. actual RPM (actual is usually higher)
Divide the actual by commanded, get 4 percentages
average all 4, or the two that are closest to the RPM range you usually run
Multiply your wizard max rpm by that percentage. Example: I usually end up on 24K systems around 25.5k
Restest as above and make a minor adjustment if needed.

FYI: 1% of 24k is 240 rpm. Dont expect to get much closer than 1-2%, especially across the whole rpm range

[toymakerSKC]

I have been using testing my Acorn CNC controller in conjunction with CNC
12 Mill (free) version 4.? to control my Bridgeport Series II CNC upgrade.
It has worked great, producing all the simple parts I have used for testing.
I was ready to purchase CNC 12 Pro Mill and I discovered version 5 had been
released. I mistakenly upgraded to the free version of CNC 12 version 5,
thinking that I needed to upgrade the free version prior to purchasing the
pro. Obviously I was wrong.

My problem is that after an extended struggle to get my machine back to the
state it was in before the upgrade, my spindle speed is no longer near
correct. I watch Marty's video on bench testing the analog output, remove
my acorn controller from the control cabinet and attempted to go back to
basics and bench test the system. I have discovered that the maximum
voltage available at the analog output is 5vdc (0 - 5vdc). The spindle
bench test program fails because I can not obtain noted voltages for each
step. the voltage readingss are approximately half of the target voltage
for each step. I suspect that there is a parameter to select the output
level between 0- 5 V or 0-10vdc. However I have not been able to find that
parameter.

Can anyone help?

See Acorn Report below

report_78047348EA58-0719192296_2023-05-24_16-20-10 (1).zip

Acorn report

(814.08 KiB) Downloaded 1 time

Regards,
Steve Curry

[Sword]

Take a look at the Spindle configuration page in the Wizard, there's a toggle for limiting the analog output to 0-5v.

[toymakerSKC]

Thanks Scott
That's exactly what I was looking for. Must've stared at that for hours and it didn't register my old brain.
Regards,
Steve