Electro-etching steel. Baby steps.

Alright. Got a request to make an embossing roller for leather. They usually look something like this:

Now, the first solution I thought of, was a CNC mill with an A axis. an A axis is a rotating axis something like this:

That would have been quite ok, but I found out that the maximum width of the design will be 10mm. And the design will be a traditional Romanian pattern like this:

 

Obviously pixel art is not an option for a CNC mill. Sharp corners can’t be milled like that. Plus the mill would have to be like 0.1 mm in diameter. Not ok.

Then I thought about a way to do it in-house. Electro-etching and masking with vinyl cut on the Silhouette portrait. After trying to cut the pattern out at the correct 10mm wide scale, it became apparent that the design was too intricate for a cutter-plotter to cut. I then scaled the pattern to about 25mm wide and cut it out in order to test out at least the etching depth. I’m assuming that I will somehow be able to toner transfer the pattern onto the roller. Somehow.

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This is how it came out. To the right you can see the failure that is the 10mm wide attempt.

The next step was preparing the etching solution. I decided to eye-ball it, and used half a cup of salt and a cup of vinegar to about 5 cups water. Used a regular car battery charger as a power supply (even though a lower voltage should produce less pitting), and connected the positive terminal to a bit of steel pipe which I previously sanded, de-greased, applied vinyl on, and the negative to a sacrificial bit of steel. Left it to bubble for an hour. I’ll release a video about the process as soon as I manage to get the files off my phone.

Here are the results:

 

Observations:

  • Pitting not so bad as expected
  • An hour was enough for about 1 mm deep etching.
  • Vinyl did not come unstuck
  • Etching obviously deeper on side closer to sacrificial steel connected to negative. (expected this. was planning on using a larger diameter steel pipe around the part to be etched as a negative pole)
  • Also tried with spray paint. Works just as well as etch-resist. Toner should also work fine.

I’m pretty stoked about these preliminary results. Actually planning on using this technique in the future for signage and similar stuff. Also planning to try out brass.

EDIT: Uploaded a video. Check it out, and don’t forget to subscribe:

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