Tormach PCNC 1100 Spindle Question #3

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CNC Dude

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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
 
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.
 
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
 
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.
 
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 ?
 
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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