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Author Topic: Feed Hold loses steps  (Read 2756 times)

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Feed Hold loses steps
« on: December 28, 2006, 02:48:27 AM »
{I accidentally posted this in the General Mach discussion area.  Sorry for the duplication.  Is there a way to unpost something?}

I have found the following during testing:

The test involves running the router around the outer perimeter of my table (24 inch by 12 inch) and back to a dial indicator to check for lost steps.  I start at 0,0 then go to 0.5,0 then 23.0,0 then 23.0,11.0 then 0.5,11.0 then 0.5, 0 and back to 0,0 and the dial indicator.

1) No steps are lost unless I pause the program by pressing Feed Hold followed by Cycle Start.  If a Feed Hold is executed, it will frequently lose steps (anywhere from .005" to .075"), but only on the x-axis.

2) Normally, the G-code display highlights the block being executed, but after a Feed Hold, the highlight stops updating although the program does run to completion.

3) After a Feed Hold, a rhythmic pulsation appears during y-axis motion that did not exist prior to the Feed Hold.  In spite of the pulsations, y-axis motion remains accurate with no apparent loss of steps.

4) If a I do a Feed Hold early in the first traverse of the x-axis and nowhere else, it often completes the circuit without loss of steps, although the afore-mentioned rhythmic pulsation during y-axis movement still appears.

Offline Chaoticone

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Re: Feed Hold loses steps
« Reply #1 on: December 28, 2006, 08:00:20 AM »
Hey Bob,
     You can go view your original post and delete it from there. Upper right hand corner. I will get this one for you. There are some feed hold issues and the guys are working on them. I'm not aware of it causing skipped steps. Are you running in single block by chance? CV mode?

Brett
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!

Offline Chaoticone

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Re: Feed Hold loses steps
« Reply #2 on: December 28, 2006, 08:04:54 AM »
Bob, I forgot to mention, download version 2.0.029. Most of the feedhold bugs have been killed in it.

Brett
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!