Head/Head 5 axis kinematic calibration

[huskermcdoogle]

Guys,

 

I am looking for a little advice on a quick and somewhat painful, but good learning experience about calibrating a 5 axis machine to get it back to an acceptable level of accuracy.  Granted we are talking a Head/Head router, and it cuts wood.  So the ball park I am looking for is <.05mm.  Right now I know I have some issues because if I back bend the B, I am about .25mm lower than if I am B positive.  I understand the geometric issue going on here, but am wondering if there is a way to use a ball bar to identify these errors in a somewhat painless manner. I have a QC20-W ball bar at my day job that I can borrow if I need.  Also, I do know most of the parameters that need to be adjusted to get some of this stuff in, but am just looking for some general guidance on the subject.

 

The owners of this machine have crashed this machine and their other one numerous times, have no idea what they are doing, are getting better, but don't understand calibration to save their lives.  Last time they whacked it, the b pivot distance was off by .3, which caused all sorts of issues.  Their fix was to just fix the b with a rotational shift.  They showed me the parameter they changed, don't remember off hand, but it was not grid shift, I recall it being 2nd home...  Not sure how the MTB has things set up in this cast.  This of course is all frustrating when you are trying to hold <.1 in wood, nothing is centered, or it is coming out small off the rotary table turning operation, and you have a hard time measuring that tight as there are very few square or parallel faces to measure from.

 

Any experiences you guys would like to share on the subject.

 

Husker

[Guest]

Does it have a probe and a FANUC control by chance? If so I may have something designed specifically for working with the pivot points.

[huskermcdoogle]

No probe.  But it does have a 31i-A5.

[Guest]

Bummer. It needs the probe.

[Aaron Eberhard]

This would be a great time to look into the book, "Secrets of 5 axis machining" by Karlo Apro. It's going to be extremely helpful with general concepts like this as you go through trying to bang that thing back into shape..

[ERIC14779]

husker

 

email me.... I have a lot of experience with head/head 5 axis routers....

 

 

eric14779 (at) gmail (dot) com

[Guest MTB Technical Services]

Check out Renishaw's new AxiSet

http://www.renishaw.com/en/axiset-check-up--11353

 

It sounds like it's exactly what you need in your environment.

[MATT Q]

Tram procedures need to be implemented immediately.