GD&T - Use of Restrained State/Non-rigid

Paul Sarrach

@Paul Sarrach tacked your question onto a discussion which is more than 10 years old.

The purpose of the "restrained" note is so a floppy, flexible part is measured the same way every time (in agreement between you and your suppliers and your customer) and to minimize repeatability variation arising from measurements.

Without a lot of details about your circumstances, I think one solution is to construct temporary fixturing using gage blocks and pins on the work surface of your CMM. Be sure to make detailed notes and take photographs, so the temporary fixturing can be reliably re-created the next time. A note on the first article inspection report should explain temporary fixturing was used, in case different tooling is used in future inspections.
I have built a setup using a Rayco plate. My problem is that i cannot restrain it due to lack of components and it is not sitting on all four Target Datums. So I have been informed to just level off the stanchions without restraining it and I feel that is wrong and that a Best Fit Alignment would be in order.
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