'problem with arcs not coming through into the cutting program'

chris raue from bakersfield Ca. -

Does anyone have an answer for why mt fadal will not put the arc or sometimes randomly not cut the arcs and replaces them with a straight line?

We are using mastercam 9 andit all looks good until you send it through to the machine.

Comment #1 Dan (68.40.145.10) -

Post the code. Point out any G2 or G3 that is not causing an arc.

Comment #2 Vega Bill from Troy, Michigan - Fri Jun 6 14:32:15 2008

The early Fadal controls have a 24-bit radius limitation and small arc angle issues. If your program contains arc statements that have a radius larger than 8388 mm or arc segments that are less than 0.035 mili-radians you could be in for a big surprise.

I have seen Fadal’s run HUGE arcs right thru the middle of the part, and I have seen them totally ignore the arc statement and proceed to cut from the start point of the circle to the end point of the circle.

These conditions become very severe when using “Curve Fitting” or thread milling do to the nature of the arc generation.

The math problem is in the Fadal, but can be avoided by adjusting the parameters in the CAD system for arc generation once you know what the limitation is. The first step is to see if this condition exists in your NC file.

If you would like to catch these errors before they end up on your part, go to www.vegacnc.com and download the DATA-View utility. The demo will allow you to view your file and if these conditions are present….. you’ll see the flags.

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