[greenchair]

Hello,

We have some 5 axis Hermle machines that just can't seem to consistantly make nice parts and I can't quite nail down exactly why.

We do all the calibrations that we can and fine tune where possible, but toolpaths sometimes just don't match up from different tip angles. It's hard to nail down the issues and there does not seem to be repeatable.

Is this a common Hermle issue of 5-axis machines in general. I can't really blame it on setup as the errors occur pretty much with the same setup and same tool(s).

Any feedback or sympathy appreciated ; )

gc.

[RICHARD ZASTROW]

"nice parts"? "tip angle"? control? product? material? axis speed mm/sec in/min? rotary axis' rpm?

I was involved with a turbine blade project 12-15 years ago using Hermle's first 5-axis mill. At first one rotary axis wasn't fast enough. Changed to a different rotary technology. Then the control couldn't keep up. Switched to a faster computers. Finally had the best of both worlds.

However, accuracy and surface finish were very good. Machine was solid.

Then the power generation industry was "de-regulated" and I was "downsized" out of a job. Oh well. LOL

Dick Z

[greenchair]

I can't say at this point at what angles in particular are an issue. We use rigid shrink tooling and runout is minimal. It should have been mentioned that we only program 3+2 and not in full 5 axis. We just position to the desired cut angle and generate toolpath..

We cut px5 and a lot of 420 SS.

[hansdie]

Sounds as though your rotary axis transformation points are wrong.
What exactly are you calibrating and how are you doing it?
I would assume your calibrating the Rotary axis transformation points.

An easy way to check it is mount a block on the table, preferable off center, and define the X,Y,Z zero to one corner. Then Spatial Plane/cycle 19 rotate the C axis by 90 degrees and measure the same corner of the block should still be zero. Then try rotating the A axis and measuring the corner should still be zero if not you need to calibrate the Transformation points.

[Jukka Honkanen]

The first thing is the geometry of your machine, then you could define the kinematics (center of the rotary axis) better. Naturally the temperature have also some effect to your machine. If all of these have error to the same direction the result could be really bad.
We solved one Deckel Maho with similar problem with the Optosyne laser measurement and volymetric axis error compensation.

-Jukka-