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Bad Circles
« on: March 31, 2019, 12:25:06 PM »
Y-axis stalls when cutting circles but not when cutting squares. I'm using Vectric Aspire software. Vectric Aspire kind of blames Mach3 for the problem. Anything to that?

Offline ger21

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Re: Bad Circles
« Reply #1 on: March 31, 2019, 12:49:14 PM »
Aspire has nothing to do with your machine stalling.

IF you are using a parallel port, check the task manager while it's running and see what the CPU usage is when it stalls.
Gerry

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Re: Bad Circles
« Reply #2 on: March 31, 2019, 03:31:23 PM »
 Thanks for your help.  I'm running Mach3 on a dedicated XP computer  with 4gb ram and a 3.2ghtz processor, it's not on the internet. I ran the CPU processor while running the circle cutting file and all it showed was a maximum 2% usage during the whole run. The Y-axis is a RM2005 ball screw being powered by a nema 34, 1600oz stepper motor. Now when I cut squares, rectangles or anything else besides circles it cuts within .01 inches of the designed size. This is more than adequate for my needs since 99% of my work is in wood products. I run my files at 100ipm but slowed it down to 50ipm to test the circle cutting file and it did not help.
Any ideas would be greatly appreciated.
Thanks

Offline ger21

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Re: Bad Circles
« Reply #3 on: March 31, 2019, 04:46:28 PM »
1600 oz motors are the worst possible choice, and 5mm pitch ballscrews are not far behind.
Those motors lose most of their torque as soon as they start spinning, and the 5mm pitch screws require them to spin fast.
What drives are you using, and what voltage are you running them at?

Why it only stall while cutting circles would lead me to think that there's some binding in the machine somewhere.
Gerry

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

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html

Offline reuelt

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Re: Bad Circles
« Reply #4 on: March 31, 2019, 05:13:41 PM »
Y-axis stalls when cutting circles but not when cutting squares. I'm using Vectric Aspire software. Vectric Aspire kind of blames Mach3 for the problem. Anything to that?
Try setting lookahead to 200 lines or even 500 lines (default of mach3 is 20 but default of Mach4 is 200) and turn on CV mode.
If you are NOT on demo copies of Mach3 (limited to 25,000Hz), the you can set the kernel speed up to 36000 or 45000 or 60,000 depending on your PC.
My Win7 32PC with Core I5 7600 can have kennel running at 100,000Hz with excellent result. So I increase my microsteps from 8 to 16 to get smoother curves.
Aspire postprocessor probably is now using many small straight lines instead of arcs to cut arc circles. You may need a better post processor (or settings) for MACH3 in Aspire.
« Last Edit: March 31, 2019, 05:15:31 PM by reuelt »
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Re: Bad Circles
« Reply #5 on: April 12, 2019, 08:09:21 PM »
Hi; Thanks to All for your help. My ball screw was misaligned by .2mm, got that fixed. Can jog X & Y axis at 300 inches/minuets and no trouble with stalling or binding but when I cut circles it slows down to almost stopping (programmed at 100 inches/minuets. Checked CV and everything else that I could read about and nothing seems to help. Here's something strange, using Aspire 9 I did 8 circles to cut out (ran it above work surface) but on my display mode in Mach3 it is show the  circles are egg shaped. It's a legal copy of Mach3 and Aspire. any ideas.

Offline reuelt

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Re: Bad Circles
« Reply #6 on: April 12, 2019, 09:17:08 PM »
"but on my display mode in Mach3 it is show the  circles are egg shaped. "

MACH3 screen was written for 1024x768 (5:4 aspect ratio) monitor.

Are you using a widescreen monitor with 16:9 aspect ratio?
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Re: Bad Circles
« Reply #7 on: April 12, 2019, 09:24:05 PM »
Thanks, never thought of that but will check it out tomorrow morning

Offline reuelt

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Re: Bad Circles
« Reply #8 on: April 12, 2019, 11:32:00 PM »
Thanks, never thought of that but will check it out tomorrow morning
Untick the "auto screen enlarge" in Config. |general config in MACH3 if you must use a widescreen monitor for other programs.
"the gift of God is eternal life through Jesus Christ our Lord"