Machsupport Forum
G-Code, CAD, and CAM => G-Code, CAD, and CAM discussions => Topic started by: JohnCNC on February 11, 2018, 09:50:16 PM
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Hi
I am new to cnc having just built my own. I am using fusion 360 for cad and cam and Mach3. My machine is running great and cuts squares about as perfect as I can measure. My problem is that when cutting a circle it’s cutting about 2/100 small. I am not leaving any “stock to leave”or any of that. Any ideas on what could be happening? Thanks in advance.
John
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What is the smoothing and tolerances settings and are you use R (radius arcs in the pre post dialog) or I and J
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Thanks for the help -
Smoothing .0004
Tol .004
Radius Arc is not checked and I do not see an I or J.
I am attaching the G Code file.
It cuts a 4x4 box and puts a 1" hole in the middle.
Totally appreciate the help. I am going to recut it now.
John
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Try doing it with the feed and speed reduced for the circle have it at 15 in/min
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Same problem. Tomorrow I am going to try to run a 1, 2 and 3 inch hole and see the errors. I'll let you know.
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cut the circles realy slow like 5 in/min if it's still out run a Vcarve toolpath of 5 letters if this is out you have big problems or backlash
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I made an adjustment to what i am guessing is a step correction? I moved a fixed distance on the DRO and put in the difference. It was not supper precise but I then ran a test of 4 circles, 1, 1.5, 2 and 3 inch all came to within 4 thousands. I think if I work on the setting a little more i can get that even better. I did run it at 5 in/min. wow too slow. I need a new bit, I plunged it in on another test way to far and fast and toasted it! Nothing like learning.
Thanks for the help!