Milling sheet metal, can it be done ?

[homebrewed]

I have to cut a lot of 0.02" strips from 0.02" brass sheet, thinking of making a "table-saw" style plate of 1/4" aluminum to mount on the lathe cross-slide with a slot for the slitting saw, cut freehand with a fence - any shortcomings in such a setup?

An interesting idea. One issue that comes to mind is that the narrow strip might fall into the saw slot. A zero-clearance slot, much like a standard table saw, would address that.

Since the table would have to be fixed you'd need to move the fence in .02" increments. Depending on your lathe, you might be able to come up with a two-piece arrangement where the table is attached to the cross slide and the fence is attached to the compound. The attachment points for a traveling rest could come in handy for that.

De-burring the metal might be challenging, if burs are an issue for your application. .02" wide strips wouldn't be too easy to handle.

I'd love to see what you come up with. Keep us posted!

 

[jwmay]

I would like to cut shapes into sheet metal (stainless steel), thickness aprox 0.8mm.

I think I would go the route of the tin knocker. Just as there’s a pill for every ill, so too is there a tool for every fool. Not that you are a fool of course. But a shape can be punched so much faster and easier than milled.
You could use the mill to machine the tooling that could punch the shapes you want. That’d be my suggestion.

 

[maxime.levesque]

What's the difference between using a reverse helix, and milling in reverse direction ?

Then for tooling you'd use a down cutting end mill that has a reverse helix angle that drives the part into the fixture instead of trying to rip it off to give you a very very very bad day.

 

[jwmay]

What's the difference between using a reverse helix, and milling in reverse direction ?

Driving a screw in reverse vs. driving a left hand threaded screw in forward.

 

[jwmelvin]

What's the difference between using a reverse helix, and milling in reverse direction ?

In this case, the flutes would be pushing the material down, as you want, but the cutting edges would be on the trailing edges. So it would not have the correct cutting action.