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I have an IPM problem
« on: October 19, 2010, 12:04:10 PM »
I have a xylotex controler with 420 oz motors and a sony Vio with a 1.6 processor. So what is happening is that when I write a program to run 10 IPM the program only runs 9.3 IPM. I know that does not sound like much but if I write a faster program lets asy 18 IPM it runs 16.9 IPM. I have done some testing and taken the profile and put it on another machine and it runs fine. So can it be something with my PC? And if so what can I do to fix it?
Thanks in advance.
Joe
Re: I have an IPM problem
« Reply #1 on: October 20, 2010, 11:22:22 AM »
wow no one has any suggestions..

Offline ger21

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Re: I have an IPM problem
« Reply #2 on: October 20, 2010, 11:32:41 AM »
Did you check to see if maybe the feedrate is correct, and just the display is wrong? I've read that the displayed ipm can vary a little based on the actual kernel speed I think. I know mine displays a slightly different number than the commanded feedrate, but i'm going much faster, so it's not a big deal to me.
Gerry

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

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: I have an IPM problem
« Reply #3 on: October 20, 2010, 11:51:23 AM »
Did you check to see if maybe the feedrate is correct, and just the display is wrong? I've read that the displayed ipm can vary a little based on the actual kernel speed I think. I know mine displays a slightly different number than the commanded feedrate, but i'm going much faster, so it's not a big deal to me.
3

Well how would I go about checking the actual speed? I have tried to increase the kernel speed and the problem got worse.. I have done some testing and taken the profile and put it on another machine and it runs fine.

Offline RICH

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Re: I have an IPM problem
« Reply #4 on: October 20, 2010, 12:39:35 PM »
Quote
how would I go about checking the actual speed

Use a stop watch to time a long axis movement.

RICH
Re: I have an IPM problem
« Reply #5 on: October 20, 2010, 12:58:02 PM »
Quote
how would I go about checking the actual speed

Use a stop watch to time a long axis movement.

RICH

Ok I just ran a 18 inches long at 18 IPM and the machine is running @ 17 IPM. I know that its not a big difference but it s bugging the heck out of me..

Offline ger21

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Re: I have an IPM problem
« Reply #6 on: October 20, 2010, 02:38:29 PM »
What is your actual frequency? Instead of 25Khz, it's probably a bit lower? I think the actual feedrate is tied to the frequency, so if your PC runs at a slightly slower frequency, you'll get slightly lower feedrates.
Gerry

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

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: I have an IPM problem
« Reply #7 on: October 20, 2010, 02:42:39 PM »
What is your actual frequency? Instead of 25Khz, it's probably a bit lower? I think the actual feedrate is tied to the frequency, so if your PC runs at a slightly slower frequency, you'll get slightly lower feedrates.

Frequency of what? and how would I check it ?
thanks
Re: I have an IPM problem
« Reply #8 on: October 21, 2010, 08:53:33 AM »
does anyone else have any Ideas how to fix this problem??

Offline BR549

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Re: I have an IPM problem
« Reply #9 on: October 21, 2010, 05:06:46 PM »
Since Art changed the driver to LOCK ON to the kernal freq this is how it is been. That I know of there is NO way around it. Most computers are closer to the kernal rate BUT a few are slower and throw the feedrate off further.

Just a thought(;-) TP