Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Bob La Londe on February 12, 2010, 12:01:29 PM
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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.
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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?
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Nope. No over ride and the setting showed at 20, but the actual speed showed at 27-28.
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Maybe for wood routing I can take advantage of that and do all my rough pocketing at a diagonal for faster feed. LOL.
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can you attach your xml and a bit of code that is giving you this problem please.
Hood
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Can't attach the code. Was using copy cat to cut off a piece. Never saved it when I was done.
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So is it only if you use Copy Cat that you get the issue?
Hood
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I do not recall noticing it before. Sometime when I have some time I'll write some raw code by hand to test it.
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Just MDI a move and see what it does.
Hood
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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.
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Ok when you are doing that you are doing a G0 move so feedrate doesnt come into it and the DRO I think will show the blended speed. If you go to MDI and command a G1X10Y10F20 the Feedrate DRO should show that feedrate, probably slightly less in fact.
Hood