[Don Clement]

Today machined 6.25" focuser parts on a 45* angle fixture mounted on mill. The center of a tooling ball is used to locate the datum for X,Y,Z axis using centering tool and height tool #1. After the center of the tooling ball is measured the X,Y,Z axis datums are calculated from the tooling ball center. Note that the part has three 0.376" precision holes. On this fixture only two of the 0.376" holes are used to located the part and one round locating pin and one diamond shaped pin is used in a quasi-kinematic way to locate each of the six sides for machining. https://www1.mcmaster.com/tooling-co...-locating-pins I designed the parts so that everything is symmetrical so that each side is rotated 120* and when the part is flipped over the other three sides are machined from the same program. The articulating arms use the same fixture/ locating pins and same program to machine them as there are only two part types: identical top and bottom plates and six identical arms

Angle fixture

Attachment 416524

Finding X,Y axis tooling ball center using center finding tool

Attachment 416526

Finding Z axis tooling ball center using height tool #1

Attachment 416528

Part on angle fixture

[jeffrey001]

Really nice setup, thanks for posting

[mountaindew]

This is a nifty strategy. Can you explain or show your x,y centering setup a little more. Are you finding front edge of ball (Y) axis, then using a offset distance to ball center?

[jeffrey001]

Joe Pieczynski
https://www.youtube.com/watch?v=FnEl6Kj-F-E

How to use tooling balls

[Don Clement]

This is a nifty strategy. Can you explain or show your x,y centering setup a little more. Are you finding front edge of ball (Y) axis, then using a offset distance to ball center?

I am finding the X-Y center of the tooling ball using my center finder and since the angle fixture is 45* then I find the Z -axis tooling ball center using my height tool #1

Center finder
Attachment 417362

Height tool
Attachment 417366

[mountaindew]

Thanks for follow up post.
Looking at your pictures in first post, it was hard to tell how you could sweep the surface of the ball to find the x-y center. The indicator holder / setup looked funny and I mostly wanted to know your process.

[Don Clement]

Thanks for follow up post.
Looking at your pictures in first post, it was hard to tell how you could sweep the surface of the ball to find the x-y center. The indicator holder / setup looked funny and I mostly wanted to know your process.

Used to have a Blake type center finder. I don't like the idea of sweeping the probe under power so I built my own center finder using a Daedal ball bearing positioner with an Interapid Vertical TDI and hand sweep to find X-Y center of things i.e pins, holes or tooling balls. I made a 3/4" diameter arbor ala TTS so it fits the 3/4" R8 collet that is used with all the other TTS tools using the PDB. Also takes up much less headroom than the Blake. May look "funny" but works exceedingly well for me. Here is an older verson of the center finder using a Starrett TDI I ditched the TTS holder shown to save headroom and repeatable height was not needed. I really like using tooling balls on my fixtures to locate datum(s) as it is way faster and more accurate than picking up edges with an edge finder. Also tooling balls work really well on angle fixtures.

Attachment 417456