Brass Marker 9mm

This will work for a few sizes, but was designed for 9mm.
Use 4 sharpies to mark along the sides.
I used 6mm bolts to fasten the sharpies and also for the feet.

Knurls caps only for aesthetics.
Spacers are used if you have different sized sharpies and also better fastening of the bolts to the sharpies.
Dial gauge is used to center sharpies, but is not necessary.

Small Marker was used as a test before up-scaling. Two bolts seem to hold the sharpie better.

https://youtu.be/-iGjY1k-nP4