[dtengineering]

I don't believe melting and casting are disallowed by the rules... in previous years we cast and turned wheel hubs, and at least some of the aluminum in those hubs was... in a former life... sheet.

Now, I'd probably get a Q&A ruling on this, as I'd kind of suspect that "sheet" means that it starts as sheet and stays as "sheet"... but it doesn't say so (yet) as far as I know. I'd also be prepared to document the fact that whatever cast component you make started out as sheet.

Perhaps a better way would be to use a CNC machine to cut thin layers of your project from sheet stock and build up your mechanism layer by layer... you could use aircraft grade adhesives to hold the aluminum together and then go back and do a final machining pass to get everything exactly to size.

Jason