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Author Topic: calibrate mach3 to the vfd or the vfd to mach  (Read 7724 times)

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calibrate mach3 to the vfd or the vfd to mach
« on: July 21, 2016, 10:05:55 PM »
Sorry if this has been asked before but I could not find anything doing a search so I am hoping some of the Pros or others who may know can help with this. I have a CNC Pilot Pro 5050 and it uses a Watercoled Spindle and a VFD and it is wired up to have Mach 3 and the USB Controller/Handheld Jogger turn the Spindle on and off. It is wired and when I click on the Spindle + or - Buttons either in Mach 3 or the USB Jogger it takes it a while to slow the spindle down. So here is the question I am asking if anyone has ever done this and if it is even possible to make it work this way?

""How do I correct the settings to calibrate mach 3 to the vfd or the vfd to mach?"

Is the above question even possible? Thanks for any help. I thought there would be a way to make them sync up to have the same readings in Mach 3 and the VFD RPM Screen for the Spindle.

Offline Davek0974

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Re: calibrate mach3 to the vfd or the vfd to mach
« Reply #1 on: July 22, 2016, 02:11:19 AM »
Is the speed controlled by Mach or not?

If yes then calibration is via the "Spindle Pulleys" menu option, my one needed a max speed of 24000 and a min speed of -2000 to get the ratio somewhere near correct. It's not spot on but near enough, don't forget if this is one of the usual water-cooled spindles they are only usable down to about 8000-9000 rpm.

Offline mc

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Re: calibrate mach3 to the vfd or the vfd to mach
« Reply #2 on: July 22, 2016, 05:05:11 AM »
There is a spindle calibration file. If the VFD is controlled via Mach, then it will most likely be via a step/dir to 0-10V converter.
VFDs themselves usually a fairly linear relationship between input voltage and commanded speed, it's the 0-10V generator that will often not be very linear. The spindle calibration file allows you to compensate for non-linearity.

I'm pretty sure the auto calibration feature in Mach 3 hasn't worked for a good few versions, but if you do a search for spindle calibration, it should throw up some posts about how to edit the file manually. You may need to also have a search over on the yahoo group.

The other option, depending on the VFD, would be to implement Modbus control of the VFD. That way you get very accurate control, however implementing Modbus can be pretty problematic, especially if you're not of a more geeky nature!

Offline Davek0974

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Re: calibrate mach3 to the vfd or the vfd to mach
« Reply #3 on: July 22, 2016, 05:17:03 AM »
AFIK the spindle cal feature needs feedback from the spindle - tacho etc. for it to work, and from what i read when looking into this, it doesn't work very well ;)

Offline mc

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Re: calibrate mach3 to the vfd or the vfd to mach
« Reply #4 on: July 22, 2016, 05:27:54 AM »
To use the auto cal feature, you need feedback, but it got broken at some point in time.
It's still possible to manually edit the file though, but I can't remember the correct format.
Re: calibrate mach3 to the vfd or the vfd to mach
« Reply #5 on: July 22, 2016, 06:27:41 PM »
Thanks everyone and I hope there is a way to figure this out and make it work somewhat. Maybe someone will posts some good links for information that knows more than me on this issue and can make it work this way. I appreciate the feedback and help.

Offline mc

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Re: calibrate mach3 to the vfd or the vfd to mach
« Reply #6 on: July 22, 2016, 07:00:24 PM »
The key word to search for is "linearity", or "linearity.dat"
The linearity.dat is the file that stores the calibration info, but it's not user readable.

http://www.machsupport.com/forum/index.php/topic,31386.0.html has a spreadsheet for calibrating

Offline Greolt

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Re: calibrate mach3 to the vfd or the vfd to mach
« Reply #7 on: July 22, 2016, 10:26:39 PM »
..... and when I click on the Spindle + or - Buttons either in Mach 3 or the USB Jogger it takes it a while to slow the spindle down.

Sounds to me like Mach3 is controlling your VFD.

IMO modbus is a far superior way to have Mach3 communicate and control a VFD.

Have you considered whether the VFD is ramping up and/or down slowly because that's how the VFD is setup?
« Last Edit: July 22, 2016, 10:29:06 PM by Greolt »
Re: calibrate mach3 to the vfd or the vfd to mach
« Reply #8 on: July 23, 2016, 01:57:53 AM »
Greolt I am not sure to be honest as I am new and just learning or trying to learn more on this to make it work with what I have. I am not sure if ModBus would work with what I have or not so if you can give me some more information or message me I can tell you what I have and we can go from there. Thanks again everyone.

Offline Davek0974

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Re: calibrate mach3 to the vfd or the vfd to mach
« Reply #9 on: July 23, 2016, 03:31:01 AM »

Have you considered whether the VFD is ramping up and/or down slowly because that's how the VFD is setup?

If this is a pre-configured machine, probably with a Huanyang VFD and water-cooled 2.2kw spindle which is the most common setup, it could indeed be programmed with a slow curve for speed +/-

On your screen, enter an MDI of something like M03 S24000 and try and time how long it takes to get from standstill to a constant speed, normally around 3-4 seconds. Your one could just be programmed for a little extra safety margin to protect the somewhat delicate nature of these low-end drives ;)

It can be adjusted but one mistake in the settings and you will be in for a lot of head scratching and pain possibly.

When finished, just enter M05 and press enter or press the Stop on screen, spindle should stop, again time this as they will normally slow down on a curve as well rather than just free-wheeling to a stop.