How to smooth edges of blanks?

Hi,

I’m looking for some advice please on how to finish the edges of stamping blanks.

I’ve tried disk cutters and they give a nicer rounded edge to the shape but i’ve just bought a cutting machine and the shapes come out more straight on the edges.

I was looking at mini bench polishing motors but the assistant sold me a barreling tumbler machine with some mild steel shot and told me that after 10 minutes it will smooth and round the edges to be the same as the circle disk.

I tested an oval shape I cut out and tumbled it for over an hour but the edges are still very straight compared to the circle disk I have as the finish aim.

It there a way to round and smooth the edges in bulk to make it look like the circle disk? (I’ve attached photos)

I’m wanting to make large and very tiny shapes (like 5mm tiny) and it will take forever to file and sand the edges by hand on each one.

If anyone can help that would be amazing.

Thank you

Your best bet is a vibrating tumbler. Call rio grande for information.

Medium grit SC rubber abrasive wheel on your flexshaft first then tumble in SS shot or polish with tripoli, whichever finish you prefer. I usually start with a trip across my lapidary expansion wheel with a 220 grit wet belt if it is real rough, but not everyone has a lapidary lathe. 5mm is a challenge. You can superglue them to a small nail to create a handle then just roll them against whatever abrasive you are using. I usually chuck it into my cordless drill and spin against the direction that the abrasive wheel is rotating. A little indirect torch heat to the nail will make the glue let go.Peel off the residual glue with a sharp knife…Rob

Steel shot might not be aggressive enough to do what you want.

Understanding the qualities of different kinds of tumbling media is complicated. Furthermore, getting exactly what you want can require a multi-step process using a series of different kinds of media. It requires research and testing.

Judy Hoch’s book about tumbling is an excellent guide, but in the meantime, here is a brief guide to different kinds of media: Vibratory Tumbling, Deburring Media for Mass Finishing Equipment | Kramer