Stamped letters

[jpaul]

I am in the final stage of making a boring head design by George H. Thomas. I am proud of my workmanship to date but now I face the problem of lettering the graduated dial.

The dial is brass, one inch in diameter. Looks like a coin. I need to letter the dial at the 0, 5, 10 ,15, and 20 graduations with a letter height of approximately 1/16". My previous attempts at stamping have left a lot to be desired. What are some of the tricks and/or techniques to do neat stamping job?

Paul

 

[mklotz]

That you, Paul? You can't hide from me.

I remember Norm showing a spring-activated punch holder he built at one of our meetings. You might want to inquire with him.

Seems to me that the biggest problem is getting consistent punch depth given the varying cross-sectional area of different digits, e.g., '0' has more surface area than '1'.
This is the ideal place for a drop hammer arrangement. That way, one could calibrate the hammer height for each digit (using a scrap piece of the same material to be punched).

Now go to the "Welcome" section and introduce yourself (and our club) to the fine folks on this board. Post some pictures of your engines. We like pictures.

 

[lugnut]

Paul, you might take a look at this letter stamp holder that you could build.
http://homepage3.nifty.com/amigos/stamp/punch_mark_holder-e.htm
Mel

 

[cfellows]

Nice setup there, Mel. I need to make something like this one day. My punched letters and numbers, done freehand leave a lot to be desired!

Chuck

 

[Bogstandard]

Paul

Here is a little something that might help

http://modelenginenews.org/meng/upt/tools.html

Clicking on the piccies also brings up to full size

John

 

[jpaul]

Marv,
Yes, it is me and I took the time to log into the Welcome Section and post a couple of pictures of my engines. I also talked to Norm. Norm did a very nice job stamping 1/16" numbers on his radial dial. I understand he didn't use a guide! I wont try that.

I like the tool set up that Mel posted. Like every project we undertake, the initial project leads to several other mini (and not so mini) projects.

Today I made a visit to a local engraver. He was unable to accommodate me because his machine only did flat, straight in a line lettering and he didn't have a fixtures to do radial lettering. I offered to make a fixture to fit his computer driven engraver but he was not interested. It was too much trouble. He had Bigger Fish to Catch.

 

[mklotz]

Paul,

Good on you. Thanks for becoming a member. I hope to 'meet' you here often. I think you'll like this forum.

My experience with manually hammering stamps has been less than happy. Inevitably, the first blow is too light and then it's difficult to reseat the stamp and make another blow without accidentally producing a double image. Then the second blow is too much and the imprint is too deep.

Years ago, I added a fitting to the base of the ram on my arbor press to hold pins of varying size for pressing out pins, etc.. It would be easy to make something similar to hold (square) number stamps. Make a base that clamps to the press table and holds the brass wheel at the correct angle and allows the wheel to be indexed (via its own already present divisions) to each stamp position.

The advantage of using the press to make the imprint would be positioning repeatability and fine control of the pressure applied to the stamp - perhaps measured by a dial indicator that registers 'penetration'.

I've never tried it so I can't speak for its efficacy but it might be something to consider and it's easy to try out on some scrap.

BTW, the new boring head looks great! Just like the pictures in "The Model Engineer's Workshop Manual".