Etcher/marker

[Gordon]

Does anyone have a good way to mark tooling. I am talking about marking the size on small cutting tools like reamers etc. Things like the vibrating engravers will not mark hardened tools and a rotary engraver does not work well on small diameter tools like 1/8". Electrostatic engravers are too expensive for limited use. Things like sharpies and magic markers soon wear off. It does not have to look like a piece of art but it has to be readable.

Gordon

 

[wespete66]

I've started using small adhesive labels, wrapped around the item & the ends stuck together, similar to how cables are done. I use paper labels so they're easy to remove for use, then replace it for storage again. Ideal? Not at all, but it works till something better comes along..

 

[BaronJ]

Hi Guys,

I use an electric engraving pen ! If its conductive it will engrave on it. I did post pictures quite some time ago of my engraver but I can no longer find them on this site.

So apologies for re-posting them:

This is a very simple device but very effective. The stylus is a hardened steel needle, in this case an old gramophone one. Inside the holder is a very long small diameter copper coil. The transformer output isn't rectified and is a low voltage at several amps. In use the tip vibrates very rapidly creating a very fine spark. A bit like an EDM machine, but it allows you to write just like you would with a ballpoint pen. By changing the needle size you can make the etched writing larger or smaller. In practice as the tip wears the writing gets thicker anyway.

There are two electrical connections, one to the pen the other to the work who's surface that you want to write on.

This device dates from the end of the war about 1948/50

 

[Gordon]

Baron. That is exactly what I would like but I have no idea where to find one.

 

[BaronJ]

Hi Gordon,

I would imagine that you would be very fortunate to find an "ActoGrap" like mine ! After all its around 70+ years old.

However the concept is quite simple.
Inside the handle is a long coil of copper wire. I've no idea how many turns, but the tip starts to vibrate the instant it touches the workpiece.
The tip is attached to a steel rod running part way inside the coil of wire.

So it would be easy to make one !

 

[rickhann]

Just google "spark gap electric engraving pen". Sit down when you see the price for a Swiss made one.
Rick

 

[Poppy Ott]

When I was a HS freshman, making these was one our first shop assignments. They are not complicated.

 

[Vietti]

I'm old fashioned so bought a name stamp from Brownells years ago, still going strong and its technology I can understand.

 

[jack620]

...a rotary engraver does not work well on small diameter tools like 1/8".

Gordon,
Unless you have superhuman vision, you're going to need a loupe to read the engraving on a ⅛ diameter tool. In which case why not just reach for the digital callipers and measure the diameter of the tool? If the tool I want to use isn't in its original packaging with the size marked on it, I always measure first if the job is critical.

And how are you going to engrave on a ⅛" tool anyway? You would need an extraordinarily steady hand.

 

[bmac2]

Hi Gordon

Found an article “Etch Your Tools with Metal Etching Pens” on the Vintage Projects site with links to an article from November 1968 Popular Science. Hope this helps.

Vintage Projects!

 

[BaronJ]

Hi Guys,

Give me a bit of time and I will take mine apart and measure it !
I do know that the construction is very simple ! It would make a nice construction project.

 

[Steamchick]

Like this one?
"Electro-engraving Machine SG-1 Double Colour Metal Spark Electric Engraving Pen"
£95.00 from China.... on E&@y

 

[almega]

I don't know where you are located but I have something like this and it works for my needs and it is only a little over USD$20.
https://www.amazon.com/Electric-Eng...t=&hvlocphy=9015099&hvtargid=pla-735974778223

 

[L98fiero]

Hi Gordon,

I would imagine that you would be very fortunate to find an "ActoGrap" like mine ! After all its around 70+ years old.

So it would be easy to make one !

I suppose you could buy the new SPI one for $600 or a used unit like theone you have for $100 less but here's a Youtube video of one that would be a lot less expensive.

 

[Gordon]

Gordon,
Unless you have superhuman vision, you're going to need a loupe to read the engraving on a ⅛ diameter tool. In which case why not just reach for the digital callipers and measure the diameter of the tool? If the tool I want to use isn't in its original packaging with the size marked on it, I always measure first if the job is critical.

And how are you going to engrave on a ⅛" tool anyway? You would need an extraordinarily steady hand.

I have marked things down to 1/8 with a rotary tool but I have had very limited success. As for measuring a reamer, it is fine if you have an even number of flutes but with a three flute reamer direct measurement does not work.

Some time ago I got about 30 odd sized reamers and they are mostly marked but the the etching is extremely faint and hard to read. I would like to mark them so that I can actually read them.

Gordon

 

[Gordon]

I have looked at several YouTube videos and the ones I have looked at either show someone using a completed unit or a chemical etch. A couple of videos show a pen in series with the ground side of a load like a lamp using household voltage. I am not that desperate. I have not been able to actually find plans for a low voltage pen. I had some plans several years ago which used a car battery and I built it and it did not work. I cannot find those plans again but I will keep looking.

Gordon

 

[smittman]

Here's a cheap way to chemical etch



Dave

 

[jack620]

...but with a three flute reamer direct measurement does not work.

I didn't know such a beast existed.

 

[BaronJ]

Hi Gordon, Guys,

Some more pictures of the inside of my ActoGrap pen.

There are 60 turns of 1.2 mm cotton covered wire wrapped around there. To days equivalent would be Teflon covered, but the core wire diameter would be a lot smaller. Enameled wire could also be used and would be closer to the same wire gauge. The resistance is very small, I measured it at about 0.03 ohms.

The needle head is made from soft iron with a 2 mm hole for the needle. Its held in place with a small screw. I've not determined the size or thread yet, but I suspect a BA size.

This picture shows the brass strip used to connect the needle head to the end of the coil of wire wrapped around the core.

The transformer produces 5 volts AC at 5 amps. The whole assembly pen and transformer get quite warm after several minutes use. Unfortunately the instruction sheet is no longer with the pen, so I'm unable to quote any usage recommendations from it.

I've started to draw this up with accurate dimensions which I will post later.

 

[Gordon]

Hi Gordon, Guys,

Some more pictures of the inside of my ActoGrap pen.

View attachment 126253
There are 60 turns of 1.2 mm cotton covered wire wrapped around there. To days equivalent would be Teflon covered, but the core wire diameter would be a lot smaller. Enameled wire could also be used and would be closer to the same wire gauge. The resistance is very small, I measured it at about 0.03 ohms.

View attachment 126254
The needle head is made from soft iron with a 2 mm hole for the needle. Its held in place with a small screw. I've not determined the size or thread yet, but I suspect a BA size.

View attachment 126255
This picture shows the brass strip used to connect the needle head to the end of the coil of wire wrapped around the core.

The transformer produces 5 volts AC at 5 amps. The whole assembly pen and transformer get quite warm after several minutes use. Unfortunately the instruction sheet is no longer with the pen, so I'm unable to quote any usage recommendations from it.

I've started to draw this up with accurate dimensions which I will post later.

That does not look like it justifies the $500 price the present day ActoGraph unit sell for. MSC sells one for $498 but they also list a spare ground cable for $61 and that is nothing but a piece of wire with an alligator clip. It looks like it should be fairly easy to make one.

It looks like there are contact points on the end of the coil. I assume that means it acts as kind of a buzzer/vibrator in operation.

Thank you for your efforts. Looks like I may have another to do project. I am looking forward to a more detailed drawing.

Gordon