Lathe radius comp question G41, G42

[yardbird]

The geometry page should show the radius value of the tool point radius. The wear page should be 0. Otherwise you're comping the radius twice. The radius value in the wear should only be used to fine tune the radius on your part, should it be just a tad off from what you programmed it to be.

I guess I see what you’re saying but if you are using the "R" on the wear page to incrementally tweak "radius on your part" wouldn’t that be affecting everything, angles, drafts, chamfers, the whole ball of wax? Although in theory it makes sense, I have never had to do it.

As to TNR comp sometimes it is a PITA and I toss it out the window and figure it in the numbers of tool path from the imaginary tool point. I do this when profiling a feature with the cutoff tool on the left hand side in a pocket or tight spot almost always.

Does the control compensate for the tool radius when swinging a radius the same as it does for a draft or angle? It very well may but when I draw the TNRC on my drawing to figure it into the path it doesn't look like it.


Brent

 

[Dave K]

I guess I see what you’re saying but if you are using the "R" on the wear page to incrementally tweak "radius on your part" wouldn’t that be affecting everything, angles, drafts, chamfers, the whole ball of wax? Although in theory it makes sense, I have never had to do it.

Yes, it will affect all things like angles and radii on corner breaks and stuff like that. But, usually, you might have a feature like a certain sized radius on the od of a part, that has a tight tolerance on the size of the radius. You can use the "R" comp in the wear feature to bring that into size if it's off just a bit, but usually, these are very small increments that you would adjust. Not enough to cause much concern on corner breaks or chamfers.