Electronic etching power supply

There are some large plotters that come with engraving heads.

With good work illumination, you can use the machinst's ruler, protractor, squares, and other layout tools with a carbide scribe. A hand scribe is good. An electric engraver is OK if your illumination is good and the work is at chest level.

You either draw the dial on a large piece of sheet steel, using the edges as your "drafting machine", or you bury the work in a near net shape hole in sheet stock of the same thickness. If you're doing one, the former. If you're doing more, the latter.

To avoid damaging the oxide coating, you can use plastic drafting rulers and triangles, or a plastic armed drafting machine. I hope to get a clamp on drafting machine soon.

If they won't resist the force of the engraver, tape them in place and make multiple strokes.

You can actually do an engineering drawing with notes, arrows, and dimensions this way on a sheet of black anodized aluminum. A simple drawing done that way, for a building installation, say letter size, would go for thousands of dollars. Or you can go with Metalphoto.

There are plotter/cutters for cutting stacks of denim to make jeans. They have various heads for doing things like preparing one-off cardboard cartons, printed, scored, and cut, that will be printed on a four color press in volumes of hundred of thousands, during retail test marketing of a new product.

Yours,

Doug Goncz Replikon Research (via aol.com)

Nuclear weapons are just Pu's way of ensuring that plenty of Pu will be available for The Next Big Experiment, outlined in a post to sci.physics.research at Google Groups under "supercritical"

There's a coil and set of contacts in the pen. The contacts are held normally closed by a spring. When you touch the pen to the metal, the circuit is completed. The current flowing through the coil now pulls the contacts open, breaking the circuit. The spring forces them closed again, and the cycle repeats.

The result is a series of closely spaced pits in the work (the slower you move the pen, the closer the spacing). If you move the pen fairly slowly, you get what amounts to a continuous line engraved in the metal. If you move it fast, you get a dotted line. By adjusting the spring tension, you can adjust the depth (width) of the pits, thus determining whether you get a fine or heavy line.

Any fairly high current 12 volt supply will power it. A car battery works nicely.

Gary

Eastwood's stitch welder does this, too, and I have tried a caron in it, but not for drawing lines.

Yours,

Doug Goncz Replikon Research (via aol.com)

Nuclear weapons are just Pu's way of ensuring that plenty of Pu will be available for The Next Big Experiment, outlined in a post to sci.physics.research at Google Groups under "supercritical"

The coil(or spring) in a stitch welder wouldn't be stout enough. You just want the circuit closed long enough to make a pit, not long enough to produce a weld.

Gary

Well, while the engraver is superior, the stitch welder does break the circuit efficiently by retracting the electrode. This modulates the arc length in welding and can agitate the puddle without breaking the arc. When used as an engraver, at lower voltage and current, the arc is not self-sustaining and it just makes the repeated pits.

Uh, I meant a carbon, not a caron. What's a caron?

It sounds like a scriber driven by AC would do this nicely.

Yours,

Doug Goncz Replikon Research (via aol.com)

Nuclear weapons are just Pu's way of ensuring that plenty of Pu will be available for The Next Big Experiment, outlined in a post to sci.physics.research at Google Groups under "supercritical"

Thanks for the replies.

I'd like to try etching graduation lines on dials for leadscrews (on the outer cylindrical surface of disks) The numbers would be done in a separate operation. I can use the scrape or shaper-type method moving a cutting tool with a carriage, but I'd like to discover a method to do this electrically.

I would need to index the dials, so I'd like to find a spark/burn method that wouldn't require the indexer to be submerged (as in an EDM process). Building an EDM and having the indexer above the EDM oil/solution, and adding a spindle that could be submerged would be more effort than I'd want to get involved with, since I just want to do a few parts.

I'd like to have a setup in the future that would permit indexing and engraving or burr cutting of graduations. I don't presently have a precision high speed spindle to accomodate this.

Recent 'net searches have shown electro stylus mechanical pencil-style etchers that etch by impact. I haven't found any etching power supplies or plans to build an arcing power supply, although I did find some books for sale for building homebuilt EDMs.

This one appears to use an electric (impact-mechanical) engraver to bounce or reciprocate the electrode, which might be a worthwhile technique to try with an arcing etch setup.

I suppose a motor and cam could be an appropriate method to use to bounce the electrode.

Thanks in advance for any additional insight that you might want to add

WB ...............