Hi all, I've been using Mach3 for a while now from time to time but recently come into a major issue thats causing me to want to change cam package. (Not changin mach3 though its cool).

Problem is when I do the toolpath simulations it looks great, the tool does exactly what its supposed to, I export the GCode, and send it downstairs to the mach 3 machine to start cutting some wings, normally moulds in MDF. Sure enough, it starts out great, but then it starts to cut little gouges in the wing, maybe a mm or two deep, or maybe just makes stupid little sections of the leading edge a bit further out then the rest of the wing, then returns to normal, and repeats this till the wing looks like a serrated edge wing...great....

What could be causeing this? I shouldn't have to be using BOG on my wings...arhghg. I checked the machine for missing steps but its not, it finds 0-0 no problem again,
I've tried CV mode on and off, arc-line approx on and off, and combinations of both, nothing seems to help, so I fear its the post processor from featurecam (old version)and mach3.... I was using the post processor available here. I"m looking at buying a new cam package because of it, I dont know maybe gibbs cam?

Can anyone suggest what the problem is cause I have no freaking idea anymore and may as well go kick a kitten or something to vent my frustraition...maybe a puppy. (I'm joking of course).

Gary,
Could you post the Gcode and a version 12dxf of the wing.
What diameter cutter are you using?
RICH

Here you go mate. Thanks
Doing the whole lot with a 1/4 inch (6.35mm) flat end 4 flute end mill. I'm happy sanding off the little scallops as I need to sand for surface prep anyway. But big gouges aren't cool. The zip file is attached.

Gary,
I tried your file but it's a 3d and creates propblems when i try to backplot it. What i was going to look at was the toolpaths to the actual outside profile and see if those serrated edges were showing up and to what degree. My quess was that the overlap of the cutting may want to be increased, or a ball end tool and maybe of smaller diameter to get rid of the serrations.
RICH

Rich Give me a sec to climb down off the pile of puppy corpses and I'll upload you a 2d V12 DXF in a sec I appreciate your efforts here.
I have tried doing a scallop finish with a ball end cutter but it ends up cutting its own little groves too... here kitty kitty.
Gimme 5 mins

Here you go, I'm not great at this exporter but let me know if its not a 2D dxf.
Cheers. I'm also going to try a fanuc code but it seems to call G45 like another was having, so i'd have to set manual G43 and just muck around till I get something that works. *Pulls out hair*

Gary,
DXF was still 3D. No joy here for what i wanted to do so don't think I can be of help.
RICH

Ok I got a friend to confirm this is top down 2d View,
goodluck, if it still aint right not to worry thanks anyway.

No joy. Still a 3d isometric.
RICH

Hi,

I have just had a look at your g-code and it is looking to me that the CAD model is not accurate, was the output file only to 2 decimal places, its as if the ends of the arcs are missing.

Graham