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problems understanding PWM and spindle settings
« on: November 19, 2011, 12:48:28 PM »
Hi

My friend is having some problems understanding what the settings should be in the motor tuning and PWM settings in mach three. 

he purchased this.  http://www.ebay.co.uk/itm/160673143941?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Nice bit of kit,  unformtunatly, you could fit the instructions on the back of a machbox, and then there in chinglish.  We have mannaged to muddle our way through by reading the mach 3 docs so far but are stuck getting the spindle to work properly, or at all sometimes.   

the spindle is 1.5kw chinese  http://www.kelinginc.net/KL-1500.PDF   

anyone know what the steps per/accel and vel settings should be for this. 

Furthermore, we are struggling to understand what affect the PWM has,  any pointier.     We have his pc running at 25,0000 hz    all other drives are working fine.   

any help or pointers would e very welcome

the spindle seem to either not work at all ( Midi command ) or work occasionaly,  when it does work, it goes through the spindle callibration ok,  when it doesnt work,  it says either pwm to low bumped to minimum setting or to fast for pully.  We have the pully set up correct i thing ( min 6000 max 24000  ) althoug we have been messing about wit the motor tuning settings.   
Re: problems understanding PWM and spindle settings
« Reply #1 on: November 20, 2011, 07:11:00 AM »
any suggestions, even a guess would do at this stage

Offline ger21

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Re: problems understanding PWM and spindle settings
« Reply #2 on: November 20, 2011, 08:45:50 AM »
HOw is the VFD connected to Mach3?

Do you have some type of PWM to 0-10V converter?

Quote
anyone know what the steps per/accel and vel settings should be for this. 

I don't believe they have any effect, as the VFD should handle all of that.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: problems understanding PWM and spindle settings
« Reply #3 on: November 20, 2011, 10:42:05 AM »
Hi 

It all connects up through the printer port.    There are two boxes of electronics, ones seems to be power for the spindle, that connects in to the other box thjat i presume is the stepper controller ( big box ).  Everything esle works fine, 

Quote
"I don't believe they have any effect, as the VFD should handle all of that."

thank you, thats saved a lot of head scratching.   ::)

do you know what formuals or calculations i should be doing between   the PWM and base minimum steting, the PC is running at 25,000 hz

the setting we were sent say run at 100hz    PWM is 10   and minimum is 2.     Our problem is the PC does not play well running at 100hz, but is ok on lower settings.   

The spindle is set for 6000 min  24000 max in pully settings, am begingin to think maybe the spindle is faulty but it runs thropugh the callibrations fine, just doesnt run when you tell it to in gcode all the time

Offline BR549

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Re: problems understanding PWM and spindle settings
« Reply #4 on: November 20, 2011, 11:11:03 AM »
Might want to post a copy of the XML to have it checked here.

Just a thought, (;-)
Re: problems understanding PWM and spindle settings
« Reply #5 on: November 20, 2011, 11:21:08 AM »
thnaks

i will post the xml later tonight,  as the mill is at my friends house.   

Offline BR549

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Re: problems understanding PWM and spindle settings
« Reply #6 on: November 20, 2011, 11:31:47 AM »
You should not be trying to run the Machine at 100hz  drop down to about 35 and test it.

(;-) TP

Offline ger21

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Re: problems understanding PWM and spindle settings
« Reply #7 on: November 20, 2011, 12:04:11 PM »
Hi 

It all connects up through the printer port.    There are two boxes of electronics, ones seems to be power for the spindle, that connects in to the other box thjat i presume is the stepper controller ( big box ). 

Ideally, you really need to know what's in the box controlling the spindle, as that should dictate what settings you need.

The main issue though, could be either the VFD settings, or the PWM settings

Quote
it says either pwm to low bumped to minimum setting or to fast for pully

This usually means your g-code is telling Mach3 to spin the spindle slower than you have it set up for. Since you appear to have it set for 6000 rpm, you probably have an S5000 or lower in your g-code. Get rid of that, or change it to S6000, and the error should go away. But, note that that error shouldn't cause the spindle to not run, it should just be running at the minimum of 6000.

Try setting the PWM Base to 50, and the minimum to 5-10%
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: problems understanding PWM and spindle settings
« Reply #8 on: November 23, 2011, 03:23:40 AM »
Hi

set it up on a different pc,   same problem.

here is the xml file.   ( attached )   i will take a picture of the electronics later.

spindle sort of works when you first switch iy on, then only gors slow ( very ) or last night it made a nouse without turning one time  when we tried to run it.   The spindle callibration graphic looks odd as well.  does up to about 10% with the calculated line, then  goes straight up
Re: problems understanding PWM and spindle settings
« Reply #9 on: November 24, 2011, 08:36:02 AM »
Just an update, i will post the picture later of the settings and the electronics inside the box

Strange thing just happend that may help us solve this. 

As  i said before, the spindle runs when you use the claibrator in mach3,    it sounds fine getting up to 8000 revs,  then from 8000-23500   it sounds like its reving up and down slightly but doenst seem to speed up much.  22500 - 24000 it speeds up a bit    I will post a picture of the calculated curve latter.

Here was the odd bit.   Run a bit of code,  it seems to run ok at  one end of the table ( start the spindle,  but not at the other end of the board, ( wont start the spindle )). 

We then run the same code in the middle of these two points,  and as soon as it travels past a certan point on the board, the spindle makes a funny noise but keeps running,  as soon as it clears that point.  the funny noise stops. 

So, i then lifted the cable that are in the cable arm, and the noise does not come on.  we tested this a few times with teh gcode was running.   

I suspect that maybe there is some interfarence in the cable,   we are going to re-check all these later on, re-rout the cable  make sure there is no interfarence. 

The calculated curve still looks odd though,  i will post picture later.