Arc problem

[SIG]

Fanuc Oi-mc.

The program I am using has been checked but maybe I am missing a code to cut accurately.

On an entry/exit arc the machine seems to start the next block before completing the first.

Its leaving a .001 bump (stock on) while side cutting a standing boss.

I am not using cutter comp just G1, G2/3 w/ I & Js.

Does any one know whats happening and how to fix it?

I need to cut shut off rad's and I am not sure how to do it without using exact stop which would leave a dwell mark?

Thanks.

I know its not an MC ?, but people on this site seem to know alot about fanuc controls.

[ToolMan184]

Can u do an overlap?

[1 master]

maybe a better lead in and lead out angle.

[Charlie Pierson]

If the bump is at the quadrants of the boss, then try checking backlash and/or gibs

 

cp

[SIG]

I can over lap but I was wondering why is this happening? Is the accuracy being compromised at other areas of a simple contour?

 

I have tried different size leadin/out moves.

 

I have checked backlash and the entry is at 45 deg.

 

Thanks for the replys

[Guest CNC Apps Guy 1]

If you don't overlap, you'll always get that cusp. I don't know that it's an accuracy issue or anything like that but if your tool is say u/s by .0005 then you'll get at least a .001 cusp because the tangency point of the entry is not coming in contact with the tnagency point of the exit.

 

Hope that explaines it a little better.