Marking metal

[Rotate]

I saw in a catalog where low voltage power source is used in conjunction with what looks like either carbon or tungsten electrode, to write on metal. I guess it creates tiny little pitting caused by the arc. In fact, some of my cobalt endmills have this kind of marking.

Does anyone know whether you need ac or dc power source, what the electrode is made out of, and what the voltage/current combination should be. It looks like a nice way to mark on hardened parts.

Albert

[Peter S]

Rotate,
I can't help with much detail, but there was a similar system available for DoAll bandsaws. This is a pointed copper "Etching Pencil" that connects to the "anneal" circuit of the bandsaw welder. The bandsaw table acts as an earth. It is good for marking hardened tools etc., though I personally prefer a small tungsten burr in a pencil-sized air grinder. I am not sure of the output of the anneal circuit, I think it is about 1 1/2 volts, ??amps. The handbook says..."Etch with sufficient pressure to prevent the point from arcing, but not great enough to destroy the copper point". Describes it as "miniature arc welding".Tungsten may last longer?

[Thrud]

Albert

In another older thread this was discussed a little. The marking method you refer to on the shanks are fron a YAG laser engraver.

Travers www.travers.com has the "Etch-O-Matic" system - not to be cornfused with the highly sought after "etch-a-sketch" (I seen a hoser convert one to use with his computer using postcript - still had manual reset, invert & shake).

Sorry about the meander down memory lane...

Anyway, the Etch-O-Matic does an electro-chemical marking by accelerating the chemical etch with DC. (Copper Sulphate? for steel) In the older thread one reply stated the chemical for steel. I saved a copy for future reference - now if I can remember where I put the damn thing....

P.S.
Dykem has some new permanent markers for metal identification and what not that I have been told works well - I have not been able to get any to try yet myself.


[This message has been edited by Thrud (edited 05-28-2002).]

[JCHannum]

I have a couple of these that I have picked up. Looks like they use a tungsten electrode, or something of similar hardness. AC out put, but have not measured it. A very heavy little power supply with a voltage pot. Probably a small version of a jazzbox welder.
Have considered selling to local tatoo parlors as new method of body art.

[John Stevenson]

I made one years ago by just using a big old transformer out of a battery charger. This must have put about 15 volt out at probaly 20 amp AC. I earthed the job and used the centre carbon robbed out of an old battery.
Very crude but it worked.
This way and the vibro pencil idea is only as good as how steady you can write. Mine looks like a dyslectic spider has fallen into an inkwell.

John S.

[Peter Sanders]

Hi Albert

<font face="Verdana, Arial" size="2">Originally posted by Rotate:
I saw in a catalog where low voltage power source is used in conjunction with what looks like either carbon or tungsten electrode, to write on metal.</font>

Many years ago I made a battery powered device that consisted of the centre carbon shaft out of a standard "D" size dry cell fitted into a hole drilled into a piece of dowel.

A positive wire was attached to the carbon rod (your choice of attachment). The negative wire is attached to the workpiece.

I think a lantern sized battery was used to "power" the device.

Just sharpen the carbon rod to a reasonable point and write on the workpiece. You cannot write too much though before the devices gets very hot - hence the need for the wooden dowel to enable you to hold it (carbon rod).

Regards

Peter