[john42kx]

I am new to cnc zone but I am having a problem with bobcad cutting a flat a the bottom of an arc. it is a flat piece of aluminum .69 radius running on top it is parallel to the flat stock so slice planner makes sense. I stepped over .005 at a time using a .125 ball endmill. my tool path inside bob cad shows a stop in cut on each side of the radius at the bottom until you remove the layer with the material in it then you can see the whole tool path. In the machine it is leaving a flat in the bottom of the radius and I am not sure why it is doing this. Any help would be much appreciated thanks

[Trotline]

There's a separate sub-forum for BobCAD/CAM. A moderator will most likely move this post there. In the meantime, It will help greatly if you'll zip your .bbcd file, (In Windows, Rt-click the file, select [Send To] / [Compressed, (zipped), Folder]), and attach it to a post. That way, we can see your settings, toolpaths, etc. It'll help greatly to diagnose the problem.

Luke

[john42kx]

I attached the file so that you could see the program and tool paths thanks for you help
john

[tlharris]

This probably doesn't help, but I did open your file in V26, blanked out the solid, and the toolpath appears visually to be correct.
I don't have your post, so I don't know what your output looks like, but this looks like it would run on my machine.

[john42kx]

I blanked it out as well and I seen the same thing. Still in the machine I get about 3/16 flat at the bottom of the radius I didnt know if the problem was because tool path disappeared under the solid or not. I also stayed bak from xyz .01 so you could see the tool path out side the solid and that didnt help either. Not sure if it is a posting problem or a machine problem. The machine is a clausing knee mill with mil pwr control on it. I am wondering if it could be back lash in the z axis or if anyone else has had this problem.
thanks john

[john42kx]

got it figured out turns out it wasn't a problem with the program it was back last in the z axis. I changed the direction of the slice planner and it took the flat out of the bottom. now I just have to adjust the machine and I should be good again.
thanks for the help
john