Need Help!- Cutter Comp with spiral milling

[Buntron]

I'm having trouble with a spiral milling tool path. the path spirals down a Z profile to form a taper on the desired material.

the problem is that the tool path has to be created using CAM.

the problem is that the parts are outside the allowable tolerance (+/- 0.01mm), and to alter this I have had to re-post the tool path after altering the tool diameter to compensate.

is there any way to use cutter comp G-codes (G41, G42) to fine tune the program at the machine, rather than re-posting the program?

[christinandavid]

.01's a bit tight for milling....jeez...

If the profile is thru the part you could alter the length instead (by a few microns...)

Or maybe use a scaling command, if you have the option, on the machine?

DP

[Buntron]

The taper is +0.003 above top tolerance.

the machine doesn't have the G51 scaling command.

I know G41 would work for one level, but as soon as a block containing X Y and Z moves is read the G41 will cause the program to alarm out.

[christinandavid]

If the taper angle is constant over the entire profile, or follows simple enough mathematical rules, it is conceivable to write a parametric program - ie you could put the profile into a loop and increment your tool offsets by the required amount for each pass.

I have successfully implemented this approach to put chamfers/tapers on jobs using a ballnose cutter if I didn't have a suitable form tool.

DP

[Kiwi]

Can you generated two or three more turns of code at the start and lower your Z datum a fraction then re-cut.