I have an IPM problem

[jbcustomcues]

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

[jbcustomcues]

wow no one has any suggestions..

[ger21]

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.

[jbcustomcues]

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.

[RICH]

how would I go about checking the actual speed

Use a stop watch to time a long axis movement.

RICH

[jbcustomcues]

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..

[ger21]

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.

[jbcustomcues]

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

[jbcustomcues]

does anyone else have any Ideas how to fix this problem??

[BR549]

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