# Tormach PCNC 1100 Spindle Question #3



## CNC Dude (Feb 1, 2015)

Hi Group,

With the help from many of  you and some other folks at CNC Zone, I have been able to beat the darned challenge which is to service a spindle. I am having a hard time myself! But it appears to be working fine, so I am practically set!

Except that before I can remove the apron I have noticed an intriguing reality. This machine's spindle operates at 2X the speed. In other words, if I command to go to 250 RPM, I measure 500 RPM.

I know the belt is positioned on the correct pulley setting and MACH 3 is configured accordingly.

It is my impression that whoever owned this machine before must have modified the VFD parameters so they could run the spindle at a higher rate (2X in this case). In fact, it makes sense the spindle was all messed up because I don't think something that has been designed to operate at 5000 RPM would behave equally fine at 2X of that!

Anyway, here is my Question #3 video in case you want to watch it, but the question is quite simple: How do I revert the VFD to the original settings? Has anybody played with this before? I downloaded the VFD manual but that thing is over 100 pages long and it is going to be a while before I can magically decipher such a mess.

Thanks for any advice on this matter!


http://youtu.be/Crc3PTsoPhY


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## JimDawson (Feb 1, 2015)

Can you provide a link to the VFD manual?  It sounds like the scaling factor is set wrong, but we can't tell you what to change with out seeing the manual.


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## CNC Dude (Feb 2, 2015)

Hi Jim,

To download the manual, the company asks to open up an account. How lovely... Anyway, I have created a blog post detailing the weirdness behind this VFD issue. The scaling factor on both machines has been set to 1! Anyway, the blog posts details everything I know at the moment and provides a link to the manual in case you want to take a look. Thanks!

http://cncdude.com/?p=191


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## JimDawson (Feb 2, 2015)

Thanks for the link to the manual, very helpful.

Compare the values in PR 3.43 I'm guessing the max frequency is set at 1/2 of your other machine.  The motor speed is a percentage of the input analog voltage vs. the max allowed speed.  I think Mach3 outputs a 0-5V analog signal, and the VFD is expecting a 0-10V so you need to adjust the parameters to use a 0-5V range.

This should be a good starting point.


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## bladehunter (Feb 2, 2015)

Sorry if you've gone thru this, but have you gone thru the speed calibration as mentioned in section 9.5.8 in the Tormach manual ?


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## CNC Dude (Feb 2, 2015)

Well, well, well...

Bladehunter, I was about to respond to your question with a "yeah man, I have run this procedure at least a dozen times!" when I decided to re-read the instructions on the manual.

Like a speeding 18 wheeler truck, the dinky little detail I had completely missed, hit me right on my face!

As it turns out, I was running the tuning procedure in high gear when the instructions clearly specify low gear. There you go, 2X!

Rest assured this is a mistake I won't be committing again...

Thanks to all for taking the time to provide suggestions!


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