I always dreaded milling thin metal. without a good way to fixture. It's floppy and results in horrible surface finish etc. Then I read about using superglue and a sacrificial plate. I never would have guessed it would have worked so well and without much effort. I used a scrap piece of 1/2" 6061 as the fixture plate. The piece I machined was 1/4" thick stock machined to .185" thick. I sanded both sides with 400 grit sand paper, cleaned with acetone, applied glue, and pressed in the vise for ~ 5 minutes. I ran a 2.5" face mill .02" deep at 50 IPM and stood far away from the mill in case things went bad :-). The bond was very solid and no issues at all. To release the part I used a heat gun on the face of the machined part for a few minutes that ran under cold water. The thermal contraction of the thinner material made a "pop" sound and a tap of a hammer on the back side of the fixture plate released the work piece. I can see doing a larger number of parts in a single sheet using this method without the cost/complexity of a vacuum fixture.
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