Machsupport Forum
G-Code, CAD, and CAM => G-Code, CAD, and CAM discussions => Topic started by: Mandrake on January 19, 2017, 03:21:02 PM
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Hi Guys,
I just noticed that when using R(radius) from Fusion360 post processor the circles in Mach3 are not round. I am cutting a 10mm outer diameter with 3mm end mill, the zero is in the center. The GCode is 100% correct, so it is not an issue from Fusion360.
So i took a closer look at the generated path in Mach3 to find out the following:
On the Y axis Top and Bottom points on the circle are correct at 6.500mm and -6.500, but on the X axis left and right are -6.420 and +6.420. it is basically generating an elipse with 6.5mm and 6.42mm radii.
When using I J all works fine. So i was wondering if anyone else can reproduce this problem. It costed me a couple of hours to figure out that the issue is not with the CNC machine...
Thanks
Not working:
G3 X-6.456 Y0.748 R0.449
G2 X6.456 Y-0.748 R6.5
X-6.456 Y0.748 R6.5
G0 Z15.
Working fine:
G3 X-6.456 Y0.748 I-0.163 J0.418
G2 X6.456 Y-0.748 I6.456 J-0.748
X-6.456 Y0.748 I-6.456 J0.748
G0 Z15.
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Why not try :-
G00 X6.5 Y6.5
G03 I-6.5 F100.
G00 Z15.
Pud
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Out of curiosity is R an allowable way to define a circular motion in Mach3. While it sort of works I don't remember if it is "approved"
Mike
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Hi Mike,
Radius (R) is a Mach3 approved method - Newfangled Wizards use R for circular pocketing.
Tweakie.
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Can't answer you question.
May be something in the post processor for Fusion that you are using. If you export the drawing out for the circle see if it is a true circle
in CAD. I have just started playing around with Fusion ..............
RICH