Tool Optical Centre punch.

[Degen]

Where the optical punch really shines is when the scribed lines are done with a height gauge on a plate. The resulting mark should be within a couple of thou.

I have both, the optical gauge makes it easier when you are tired, however with proper technique old school punching has the same accuracy and believe it not faster.

 

[Downwindtracker2]

I use the two punches, a prick and a center. A prick has much sharper angle and a very sharp point.

 

[CWret]

Step 1- a sharpe automatic punch on the layout intersection;
Step 2- then a small punch on an angle if some lateral adjustment is needed (like others described above); and
Step 3- then a healthy wack with a large punch to give the drill bit somewhere to bite in.
Step 2 is optional.

Today i ordered some acrylic dowel from Amazon. An optical centre punch is going to be a project when the dowel arrives. Hopefully this new tool can take me right to Step 3.

I think getting the crosshairs accurately onto the flat bottom of the dowel will be the biggest challenge. (Oh yea, I only have a mill - so getting my mill to think like a lathe maybe a challenge too).

 

[Susquatch]

Oh yea, I only have a mill - so getting my mill to think like a lathe maybe a challenge too).

It might be easier than you anticipate. If the dowel will fit a collet, you can spin it just like on a lathe and then mount your cutting tool in the vice (or some other holder arrangement using X&Y&Z to position the tool the same way you would normally use the lathe saddle and tool holder. It won't be perfect, but the dowel isn't exactly steel.....

 

[DPittman]

Step 3- then a healthy wack with a large punch to give the drill bit somewhere to bite in.

Just one side point...sometimes on metal like stainless steel, the punch mark can make the surface work harden and getting the pilot drill bit to bite is difficult. In these cases, you want to punch mark just enough to guide the first drill bit and no more.

 

[CWret]

“It might be easier than you anticipate. If the dowel will fit a collet, you can spin it just like on a lathe and then mount your cutting tool in the vice”

Yep. I get it. The dowel i ordered is 1” diameter. A while ago i also got a 1” R8 collet so i could hold the 1” diameter steel rod i have - so now i can hold the 1” acrylic dowel and get the diameter i want with a cutter held in the mill vise.
So the fun begins