Manufacturing buy-off

Confirm static geometry is within specified tolerances

Whilst the manufacturing of the fixture is largely the responsibility of the gauge maker alone, there will be a lengthy buy-off process in which the customer must take a leading role, and this will start with the basic geometry of the fixture. A measurement report must be provided by the gauge maker and certain measurements from this report should be confirmed with the customer present prior to shipping the fixture. It is suggested that this report includes all pad and pin positions (five points each), and a sample of points on gap/flush/form bars.

Confirm fixture functionality and operating process

Functionality and operating process should also be documented in a report and again demonstrated to the customer prior to shipping. This will include the ability to hold and accurately locate the component without impeding measurement points/paths, the clamping sequence and if specified, convert from a gap and flush checking medium to a CMM holding fixture.

Carry out R&R test on fixture with component

Finally, a type 1 R&R study must be performed by the gauge maker, in order to demonstrate that the fixture is capable. This can only be carried out reliably, however, if suitable components are available for inspection, and this can result in considerable time pressure being placed on the final stages of the manufacturing and buy-off processes. The component(s) used for the study do not need to be off-tool, but must be of adequate accuracy that there are no clashes with the fixture and, of critical importance, the locator holes are correctly positioned and not oversized. Careful time management is, therefore, very important, with the fixture being ready in time for the first off-tool parts and the R&R study subsequently being performed as quickly as possible.

The details of this study should include a loading/unloading procedure, clamping sequence and measurement programme for the measurement device specified by the customer (this may have to be developed in collaboration with the customer).