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Author Topic: Feedrate glitch  (Read 4240 times)

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Feedrate glitch
« on: February 12, 2010, 12:01:29 PM »
Hmmm....  I was just noticing something while cutting off a part yesterday.  After an F20 command, and my motors set at a max for 20 I was getting diaginal cuts at 27-28 IPM.  It was visibley faster than the axis parrallel cuts.  Is this something I just have to live with?  Obviously neither motor is exceeding its individual speed, but the net result is a much faster feedrate. 

In this case I was using a full 1/8 cutter with enough rigidity and speed to handle it, but if I had been using a smaller mill and pushing my feed speed for the cut I could easily has snapped it with a sudden increase like that. 

Offline stirling

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Re: Feedrate glitch
« Reply #1 on: February 12, 2010, 12:20:07 PM »
Hmmmm back. Certainly both axes running at 20ipm would have a net rate of around 28ipm (20 * root(2)) on the diagonal but a feed of 20 means just that so something's amiss. That would be my thoughts anyway. Havn't got a feed override going on there have you?
Re: Feedrate glitch
« Reply #2 on: February 12, 2010, 03:29:00 PM »
Nope.  No over ride and the setting showed at 20, but the actual speed showed at 27-28. 
Re: Feedrate glitch
« Reply #3 on: February 12, 2010, 03:30:13 PM »
Maybe for wood routing I can take advantage of that and do all my rough pocketing at a diagonal for faster feed.  LOL. 

Offline Hood

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Re: Feedrate glitch
« Reply #4 on: February 12, 2010, 03:56:13 PM »
can you attach your xml and a bit of code that is giving you this problem please.
Hood
Re: Feedrate glitch
« Reply #5 on: February 12, 2010, 04:04:48 PM »
Can't attach the code.  Was using copy cat to cut off a piece.  Never saved it when I was done. 

Offline Hood

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Re: Feedrate glitch
« Reply #6 on: February 12, 2010, 04:06:43 PM »
So is it only if you use Copy Cat that you get the issue?

Hood
Re: Feedrate glitch
« Reply #7 on: February 12, 2010, 04:51:50 PM »
I do not recall noticing it before.  Sometime when I have some time I'll write some raw code by hand to test it. 

Offline Hood

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Re: Feedrate glitch
« Reply #8 on: February 12, 2010, 04:52:58 PM »
Just MDI a move and see what it does.
Hood
Re: Feedrate glitch
« Reply #9 on: February 12, 2010, 05:02:48 PM »
Had to wait for the current job to finish.  I was cutting some screw slots in my adjustable sphere cutter to make it more universal. 

Anyway, I just did a <SHIFT + left arrow + up arrow> and it moves at 27+.  I never noticed it before.  I guess because I'm always watching the coordinates or the cutter and work piece when I am making a manual move.