Optical Punch for Square Stamps

[rwm]

I always seem to have trouble lining up my letter and number punches. I have an optical punch for center punching that works great. Why not adapt this design to fit a square punch?
Here is my first prototype:


The lens is made from acrylic. I shaped it with a file and sand paper, then polished. It took me 3 tries to get the focal length about right but surprisingly not too hard. The diameter of the cylinder is the same as my punches 5/16".
Here is a pic of the view of a mark from the tip of a small Sharpie. Looks more crisp in real life. It is highly magnified.



This works as well as my optical center punch!

I made the base rectangular so I could adjust the angle correctly and possibly use it along a ruler or scribe line. My plan is to put down pen tip marks on the mill using the DRO and then go back and center each letter over a pen mark. Not sure how this will work out yet.

 

[buffdan]

great idea

 

[jcp]

I like this....a lot.

 

[rwm]

A word of caution. I am finding an issue with this approach. I have heavy duty stamps from CH Hansen. Turns out that some of the letters/numbers are not aligned with the shaft of the punches. They are slightly but visibly rotated. So if you line up the flats on the shaft the character will be rotated. Kind of disappointing from an American manufacturer.
Can anyone recommend a better brand of punch?

 

[rwm]

I found a great punch set! And cheap! (comparatively)

Amazon.com

These are made in Taiwan. They are less than half the price of the Hansen and twice the quality. The hardened punches cannot be scratched with a file. The letters are properly aligned with the punch shank and they make a nice crisp impression. I give them 5 stars!
Need proof?


The punch shank is .250 x .250 so I revised my optical setup by reducing the light pipe to .250 and cutting a new .250 slot in the holder. You can see my alignment came out great!

I forgot to mention, I cut the index grooves on the mill and then filled them with black touch up car paint. Then back on the lathe to remove the excess. This gives a nice crisp look.