[PCTMachining]

Afternoon team, from all the way over in Dubai!

I've got a technical question for any experienced guys out there. I'm wondering if you can share advice for measuring conditions relating to an angular axis on a 5 or 6 axis mill. i.e the A, B or C axis. I am trying to find a 'conventional' alternative to purchasing the rather expensive Renishaw XR20 system. I'm not interested in contracting out the maintenance.

My test equipment includes:

Precision ground test bar,
500 x 500mm precision calibration granite block
Renishaw QC20 ball bar
Single micron DTI
Mag stands

Conditions I can measure with granite, a test bar and DTI:

• Plane of rotation and parallelism / squareness of that plane to XYZ
• 0 point of axis
• Backlash and repeatability of axis.

However I need suggestions on a proper test method for the following:

Absolute positioning of axis through full range of motion. Take the C axis for example: C0, C90, C180, C270 are all relatively easy to measure with a test bar. But what if you want to check its positional accuracy at C5, C10, C15 etc?

Any suggestions would be welcome and bare in mind I am chasing accuracy of around 5-10 micron over say 400mm on the test bar (about 0.0007 deg error) so I'm looking for proper industry tests.

Thanks in advance guys.

Scott

[PCTMachining]

I also have a precision sphere mounted directly to HSK taper.