Cadd programming on fixture

[FAT FREDDY]

Hey dudes. I'm laying out plastic parts using fixtures.There is 3 tooling balls to pick up to get to CAR POSITION.Should I pick up the tooling balls(then hit cad = part),then do a iterative aligment in dcc ? or skip the tooling balls.
All my datums are nested in the fixture,so i cant use them for a pickup.

p.s. hey craiger, how about those yankees!

[Tony.Hirotec.Aus]

If your datums are nested in the fixture what are you iterating? If the fixture locates the datums then there is no need for any other alignment, probe your balls and if that doesnt work, see a doctor

[Peter Warcholyk]

Freddy,

I work in the plastic injection molding business, and utilize many fixtures with tooling balls.
Manually, first pick up on the tooling balls, do an iterative alignment.
Next pick up the tooling balls again in Dcc mode and do a second iterative alignment.
Note; when using the iterative alignment, there is no need to do a "cad=part".
The iterative alignment will "snap" the cad in place.

ZydecoPete

[jmgreen]

What Peter said.
One of these days I'm going to actually answer one of the questions before y'all beat me to it. Good answer.

[\v/inston]

try this guide

[JoeRZ]

I tend to agree with Tony - If your datum structure is already built in to your fixture, then those should be used.

What I would do is develop a fixture alignment program using the spheres on your fixture to locate it on the table and setup your datum frame on the fixture.
Recall the fixture alignment in your part program then compare results to your specs. I would then perform an R&R on the fixture to see if error is acceptable.

If the fixture is not repeatable (% of toleranced used - depend on cost and use) , then I would setup differently and use iterative.

My 0.02...

JRZ

Ola Amigos - haven't posted for a week or so - hope your week is going good.

[Jeffrey Lovely]

After you do your iterative alignments
measure the nets and locators and determin if this is good enough
if not you can do an iterative on the nets and locators
still no need for cad = part
then evaluate where the tooling balls are
I have never seen the tooling balls measure exactly
the error may be very small
but take a look see
and make a decision based on your tolerances