Tuning and Calibrating Spindle Speed with a VFD (inverter)

Moderator: cnckeith

cnckeith
Posts: 7554
Joined: Wed Mar 03, 2010 4:23 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: Yes
Oak CNC controller: Yes
CNC Control System Serial Number: none
DC3IOB: Yes
CNC11: Yes
CPU10 or CPU7: Yes
Contact:

Re: Tuning and Calibrating Spindle Speed with a VFD (inverter)

Post by 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
Need support? READ THIS POST first. http://centroidcncforum.com/viewtopic.php?f=60&t=1043
All Acorn Documentation is located here: viewtopic.php?f=60&t=3397
Answers to common questions: viewforum.php?f=63
and here viewforum.php?f=61
Gear we use but don't sell. https://www.centroidcnc.com/centroid_di ... _gear.html
toymakerSKC
Posts: 14
Joined: Mon Aug 03, 2020 4:38 pm
Acorn CNC Controller: Yes
Plasma CNC Controller: No
AcornSix CNC Controller: No
Allin1DC CNC Controller: No
Hickory CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: C122600
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No

Re: Tuning and Calibrating Spindle Speed with a VFD (inverter)

Post by 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 38 times
Regards,
Steve Curry
Sword
Posts: 678
Joined: Fri Nov 30, 2018 1:04 pm
Acorn CNC Controller: Yes
Plasma CNC Controller: No
AcornSix CNC Controller: No
Allin1DC CNC Controller: No
Hickory CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: none
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Thorp WI

Re: Tuning and Calibrating Spindle Speed with a VFD (inverter)

Post by Sword »

Take a look at the Spindle configuration page in the Wizard, there's a toggle for limiting the analog output to 0-5v.
Scott
toymakerSKC
Posts: 14
Joined: Mon Aug 03, 2020 4:38 pm
Acorn CNC Controller: Yes
Plasma CNC Controller: No
AcornSix CNC Controller: No
Allin1DC CNC Controller: No
Hickory CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: C122600
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No

Re: Tuning and Calibrating Spindle Speed with a VFD (inverter)

Post by 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
toymakerSKC
Posts: 14
Joined: Mon Aug 03, 2020 4:38 pm
Acorn CNC Controller: Yes
Plasma CNC Controller: No
AcornSix CNC Controller: No
Allin1DC CNC Controller: No
Hickory CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: C122600
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No

Re: Tuning and Calibrating Spindle Speed with a VFD (inverter)

Post by toymakerSKC »

report_78047348EA58-0719192296_2023-05-24_16-20-10.zip
Report
(814.08 KiB) Downloaded 28 times
Today’s problem
I have been using and testing my Acorn CNC controller in conjunction with CNC
12 Mill (free) version 5 to control my Bridgeport Series II CNC upgrade.
My mill was working great with version 4.? However after upgrading to version 5, I’ve experienced what seems like endless challenges.
Over the weekend I succeeded in correcting most of the problems I’ve incurred after the version update. The most pressing of the remaining problems, is that when I changed the spindle from auto to manual on the VCP, the spindle break releases and the VFD runs the spindle at a very low rpm. The approximate VFD speed is less than 1 Hz. Pressing the stop spindle button on the virtual control panel activates the break for approximately one second, then the break deactivates and the spindle continues rotating. Spindle Forward and Spindle Reverse VCP buttons correctly control spindle direction and the spindle break solenoid is operating correctly. This is a new problem that arose after the version upgrade. There’s been no change to wiring or hardware other than the removal and reinstallation of the acorn board to facilitate bench testing.
Scott, successfully assisted in rectifying my last problem, hope someone can do the same with this one.
Regards,
Steve Curry
suntravel
Posts: 2288
Joined: Thu Sep 23, 2021 3:49 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 6433DB0446C1-08115074
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Germany

Re: Tuning and Calibrating Spindle Speed with a VFD (inverter)

Post by suntravel »

Add a capacitor across the 0-10V Wiring.

Adjust the VFD zero spindle speed, Acorn gives a very small voltage at 0 rpm, that can be tuned in the VFD parameters.

Uwe
cncsnw
Posts: 3909
Joined: Wed Mar 24, 2010 5:48 pm

Re: Tuning and Calibrating Spindle Speed with a VFD (inverter)

Post by cncsnw »

The spindle should not be turning by itself after you press Spindle Stop, regardless of the analog trim.

On the Alt-i screen, do you see either OUT4 (SpinFWD) or OUT5 (SpinREV) remaining green (on) after you press Spindle Stop?

If OUT4 or OUT5 remains green after you press Spindle Stop, there is a problem with the PLC program.
If your VFD is enabled and powering the motor while OUT4 and OUT5 are both red, there is a problem with your wiring.
toymakerSKC
Posts: 14
Joined: Mon Aug 03, 2020 4:38 pm
Acorn CNC Controller: Yes
Plasma CNC Controller: No
AcornSix CNC Controller: No
Allin1DC CNC Controller: No
Hickory CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: C122600
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No

Re: Tuning and Calibrating Spindle Speed with a VFD (inverter)

Post by toymakerSKC »

Uwe and CNCSNW

Thank both of you for your quick response.
The VFD installed in my system is a DURApulse GS20 from Automation Direct.
This control system has been operating flawlessly for many months using version 4. 8?. Only after installing CNC 12 version 5.02 did this problem arise (this is the free version of CNC12).
Uwe What value capacitor would you suggest that I put across the Acorn analog output?
My shop is 50 miles from my home it’s going to take a while before I can see if this might be the fix.

CNCSNW I agree with you, the VFD or its wiring has never given me any problems. This quirk surfaced after the revision upgrade. I will check the Alt I I/O table tomorrow. Checking the status of Spindle Forward and Spindle Reverse outputs. In addition I will check the status of the Spindle Break output.
Is there a setting in the wizard or parameters for brake operation? It’s possible that prior to revision update the motor had always tried to rotate, however the break may have been masking the motion.
Thanks again for the help,
Steve Curry
suntravel
Posts: 2288
Joined: Thu Sep 23, 2021 3:49 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 6433DB0446C1-08115074
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
Location: Germany

Re: Tuning and Calibrating Spindle Speed with a VFD (inverter)

Post by suntravel »

Hi Steve,

CNCSNW is right, I mistook the problem for M3 S0 not for M5
With M5 the VFD analog trim should not be the problem.

Uwe
toymakerSKC
Posts: 14
Joined: Mon Aug 03, 2020 4:38 pm
Acorn CNC Controller: Yes
Plasma CNC Controller: No
AcornSix CNC Controller: No
Allin1DC CNC Controller: No
Hickory CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: C122600
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No

Re: Tuning and Calibrating Spindle Speed with a VFD (inverter)

Post by toymakerSKC »

Thank You Uwe
I'm heading to the shop at about an hour and should have better information when I return.
Regards,
Steve
Post Reply