Well, I think I have taken this engraving project as far as I'm financially able to. I feel it should satisfy 90% of the folks that want some lug engraving at about half the Phong price and for the other 10% I envy you for having more money laying around than you know what to do with!
Here's my final results:
G - Whoop nailed it, ya gotta draw 'em. I import the image into Autocad, blow it up until the characters are a couple inches tall, trace, then scale it to the proper finished size. It is then saved as a .dxf file and ran through a program that turns the .dxf file into G-code and yet another piece of software that takes the G-code and translates all "X" axis linear moves to "A" axis rotational moves. Fun stuff...
Normally the cannon pin and 4th wheel need to be higher if the dial has the really tall markers like the vintage stick DJ dials but on others, like Roman markers, the standard works fine.
Kinda hard to tell from your fuzzy pic but the end looks rounded so it was probably that way on purpose. Some sweep hands have long "tubes" so can use a short pin like that.
The seller advised me that the spring is adjustable a small amount but advised against putting a stronger spring as the tip could shatter if it was "dragged" over a rough spot. I will crank the spring all the way down on the next case but that is about the end of my experimenting.
I while back I picked up a conical diamond tip engraving bit in a spring-loaded carrier and today I finally had time to make an adapter so I could attach it to my engraver. I removed the spindle motor and mounted the the adapter in place and gave it a whirl. I also changed the gearing on my rotary axis from 3:1 to 5:1.
The drag engraving is extremely precise and fine and the 5:1 gearing seems to have taking the "jagginess" out of diagonal lines. I need to contact the maker of these diamond points to see if I can change to a bit stronger spring inside the carrier to get it to cut deeper without damaging the diamond tip - somewhat expensive...
Here's the results.