4th axis setup question...

[cc22288]

Hey all,
We run Haas rotaries on the right hand side of our tables with A-frame supports on the left side as needed. My process has always been getting the rotary straight and square, then bolting the fixture to the face plate of the rotary, then using shims on the A frame to get the A frame bearings on axis with the rotary. If the fixture slopes down from right to left, i would shim under the A frame on the left until my indicator shows it straight.

Lately I've been seeing some of the set up staff in my shop doing this differently. If it slopes down from right to left, they leave the A frame as-is and shim between the rotary face and the mating surface of the fixture. This strikes me as problematic... Then your fixture is on axis for one orientation but thrown out any time you rotate.

Am i wrong? Are they both equally valid and im just nit picking?

 

[Milling man]

Am i wrong?

No, you're right. You make the process better. The second method aligns the part in one moment, but when the axis is rotate, everything goes to hell. First of all, it is necessary to set the ROTATION AXIS of the rotary axis relative to the machine axes, after that it is necessary to set the part.

 

[dandrummerman21]

Does the boss on the end of their fixture run out when clamped to the rotary?

Does the faceplate on the indexer run out with nothing on it?

If either of those is true, they *might* be right to do it that way. Then again, if either of those is true, you probably should address the problem (bad indexer)

Does their fixture indicate in "flat" or "straight" in x/z when they are done? Probably not, and if not, then it's probably wrong.


You should measure the height of the centerline of the indexer, and measure the height of the center of the support. Whatever the difference is, you would get shims that equal that difference. Maybe an additional thou or two to account for clearance in the support bearing.

 

[cc22288]

Does the boss on the end of their fixture run out when clamped to the rotary?

Does the faceplate on the indexer run out with nothing on it?

If either of those is true, they *might* be right to do it that way. Then again, if either of those is true, you probably should address the problem (bad indexer)

Does their fixture indicate in "flat" or "straight" in x/z when they are done? Probably not, and if not, then it's probably wrong.


You should measure the height of the centerline of the indexer, and measure the height of the center of the support. Whatever the difference is, you would get shims that equal that difference. Maybe an additional thou or two to account for clearance in the support bearing.

Great points.

No the faceplate on the indexer is dead nuts. Usually the boss on the end of the fixture is really close as well when clamped. I believe you're correct.