Centering a punch mark in the 4-jaw

[Hawkeye]

I made a wiggler out of about 10" of 3/16" music wire. Ground to about 60*, with a wheel collar made for holding the wheels on the landing gear of an RC plane added near the point. The collar was to make the surface bigger to work with a dial indicator, about the same diameter as an arrow. I never felt the need for a spring on the end.

Sorry. No pictures until I get my equipment back, possibly withing the next few weeks.