Stamp and Touch Mark Press

[davec2]

Acer,

I finally had a chance to take some pictures of the hydraulic press I mentioned in your post about stamping.  This first picture is of the entire press.  It is a simple welded assembly of 2 inch square tubing.  A hydraulic jack, with a pressure gage that reads cylinder pressure, just sits on the bottom plate and pushed against the bottom of the lower, movable platten.  The lower platten has two shoulder bolts 180 degrees apart that ride in slots milled in the vertical members.  Inside the verticals, tension springs are attached to the shoulder bolts and to bolts running through the lower end of the vertical pillars.  These springs will lower the platten when the bypass valve on the jack is opened.  The upper platten is fixed to the upper horizontal frame members and has a 3/4 inch hole in the center.  The center hole will accomodate different tool holders and / or anvils.  I use the press to stamp, coin, bend tangs, bend barrels, punch out sheet, press powder, etc.  Very handy tool.



Stamps, tool holders, anvils, etc.



Close up of stamp in holder.



Stamp being used to mark a scrap piece of barrel.



In this particular case, 2000 psi is being applied to the press (this is the cylinder pressure but the cylinder has a cross sectional area of about 1.75 square inches which means that the applied force is about 3500 pounds.)

This is the resulting stamp impression.  Very even and very repeatable with the pressure gage.



Graphite EDM tool to make coining (makers mark) stamps.



Some of my makers mark stamps.



Result of quick and dirty test pressing (really coining) of 24K gold, 0.025 inch thick in a recess quickly cut by hand graver in barrel steel.  Pressed at 3200 psi hydraulic pressure - no distortion of the interior of the barrel (.45 cal, 13/ 16 across flats, no interior support)



The following is another press I used to use for making black powder.  I now use this new one with a different set of tools to press 4 inch diameter "pucks" of powder prior to corning.

[P.W.Berkuta]

That is one serious press their Davec2 . I see you did not fall asleep in your Machine Design classes . Do you have a way to limit the travel so as not to distort the barrel or is it regulated by pressure gauge only? What happens if you stamp a "soft" barrel compaired to -say a GM barrel. With all that aside I like it .

[davec2]

P.W.

The pressure gage allows me all the control I need.  There is no mechanical stop.  On all but very thin wall barrels, I would need to apply twice the required pressure for even stamping to harm the bore, so there is quite a bit of lee way.  I usually experiment with scrap material before I have at the final go around.  Also, with the work piece clamped in place, I can apply a minimum amount of pressure and then raise the tool to see how the impression looks.  If it's not deep enough, I can lower the tool again and apply a little more pressure to improve the mark.  The alignment stays in place.  It really doesn't take very long to get the hang of how much pressure is enough, for each tool size, to make a perfect mark without doing any damage.

[rich pierce]

That is the real deal.  Top notch!

[Daryl]

Barrel distrotion was my only concern - great settup, Davec2.

[Clark Badgett]

What source do you use to make the stamps?

[davec2]

Clark,

I make most of my own tools.  I make the graphite master and then have a local shop EDM the mark into a piece of hardened tool steel (usually a blank lathe turning tool).  Acer noted in his original post on making a stamp for his guns that a place called Sparks Steel Stamps will make tools for a reasonable price.  I haven't tried them yet, but I will.  I have also heard that N-Graver will make custom stamps as will a house called Micro Stamp that I have used.

http://sparksstamps.com/index.htm

www.microstampusa.com

[holzwurm]

Could you address the making of a Graphite Master on another string? That's new info for me. I have a friend who will EDM the stamp for me but I'd need to send him the master.

[davec2]

I will try to get something out tonight.

[Acer Saccharum]

Dave, wow, that's a fantastic tool! Very simple, yet effective. Totally eliminates the bounce of the stamp, and multiple uses. Good going! Very inspiring.Thanks.

Acer

[David Veith]

How or what did you remove for your gage?
David Veith

[davec2]

David,

There are ways of drilling into the base casting of a standard bottle jack to install a pressure gage.  However, since I was buying a new jack just for this press, they make them with a pressure port and I bought one of those.  I forgot where I got it, but I know I ordered it on line.  If I can find the invoice, I will send you a link.

Dave C

[msblacksmith]

could you tell us more about making the stamps?

[erdillonjr]

I only have a small touch mark but an arbor press and a 3 pound hammer works ok

[Brian]

Great idea.  I was initially worried that if I tried such a thing I'd distort the barrel, but after reading what you said it seems it's pretty much idiot proof as long as you are careful.  Sure a neat way to mark stuff.  Every time I try something like that with the hammer method I always end up with the impression being faint on one side and heavy on the other - or it skips - or jumps - or it's not straight - or it's not where I want it.

This is a great idea.  Thanks for sharing.

[Dphariss]

Barrel distrotion was my only concern - great settup, Davec2.

I would not think that 3000+- pounds would hurt the barrel.
It takes quite but. I don't know what the pressure was when Wolf ran a 1 1/8" barrel through the roll stamp machine set for 1" barrels. But it did ruin the barrel. You could see where the roll stamp had compressed the metal by looking in the breech of the barrel. This was 1137.

Dan

[davec2]

The following marks were done with the press on the brass depth gages I have been making.  These impressions were made at 2,000 psi for the shield shaped mark and 1200 psi for the oval.  These are fairly deep.  Much lighter pressures can be used and still get a very readable and consistent mark.

[jmforge]

That is really slick! You could darn near forge small parts with that thing...lol.   After trying to stamp my blades by hand and with an arbor press, I finally gave up and went with an electro-etch machine.  I could never get the stamps even.