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Tool Optical Centre punch.

Tool

DPittman

Ultra Member
Premium Member
An optical centre punch. i made a while ago as a project. If you're like me and have trouble centre punching on the line, this little gizmo is worth its weight in gold.
Yours appears to be electrically operated? How is that done? I'm just familiar with the simple painted on crosshairs to the acrylic shaft used for the magnification.
 

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
Here you go, 10sec search online.


No light on that one. I think that's what most of us old guys are looking for. Certainly what I'm looking for. I can't see well with a light let alone without.

Did I ever mention how much I hate YouTube?
 

mikefrost

Member
It wasn't clear to me what the (plastic? ) material is. And does making the 2 ends of it slightly round create the magnification lens ? I think it does, but roughly how much rounding is needed.
I scrolled back and forth on that video several time trying to ge answers, but to no avail.
Looks like I'd benefit from one of these things

Mike
 
I have one like that from LV years ago. No light is require as the optics bring in ambiant light unless fat fingers block it. The location where the cross hairs are is flat the to is curved for magnification, focal length is by eye distance to optic.

Sight, align, hold down, pull optic, insert punch, tap, done.

The base has an o-ring imbedded to help prevent movement. So a gentle touch is needed removing and inserting.

Works well, but if you've learned how to use a center punch correctly the center punch is way faster.
 

Dusty

(Bill)
Premium Member
An optical centre punch. i made a while ago as a project. If you're like me and have trouble centre punching on the line, this little gizmo is worth its weight in gold.

@toglhot perhaps you would provide this thread with the background music so to speak, list of components and (elctronics) used along with a scale drawing would be helpful.

Yes photos speak 1,000's of words and questions. Just saying!
 
I knew we had this discussion previously, here is a link to my post showing how it works.

 

mikefrost

Member
Reading this post was great, until the end, when I found that I have NOT received training on how to centre punch "properly". I just try to get it as close as I can , but seldom get it spot on.
Any chance of a description of how to do it "manually" ?
Mike
 

DPittman

Ultra Member
Premium Member
It is often possible to feel the marking lines with the punch tip and when you hit the intersecting lines you have arrived at your destination. Of course this can only be done with a relatively sharp punch and when you are able to actually score the surface with marking lines.
 

Mcgyver

Ultra Member
Like DPittman said.

I'd add, its beneficial first use a prick punch. It is sharper, i.e. the point is a smaller angle than a centre punch. Its function is really to locate the the hole so you can then centre punch. The centre punch angle is close to a drill 's so after locating with the prick punch, it squashing things down making a nicely angled cone for the drill to start in. I'm very light with the optical punch, fairly light with the prick punch and as heavy handed with the centre punch as the drill size warrarnts.
 

PeterT

Ultra Member
Premium Member
That's how I was taught. Follow a scribe line with the punch tip until you feel the intersecting scribe line. Make a SMALL initial pop. Now examine under magnification. You will see 2 V trenches & hopefully a conical crater in the center. If not, figure out which way it has to go. Position the tip back in the cone, but slightly angle the tool in opposite direction so you drift into correct direction & it becomes just a bit deeper. Rinse & repeat for accuracy required. Where most people get it wrong is a big off-centered whack, much more difficult to correct.

There is also probably a relationship between the center pop divot depth/diameter & the drill that will follow. A small divot probably isn't going to do much for a large diameter thick faceted drill. Probably best to open the center pop up with a small spot drill. The spot drill included angle should be >= the drill angle.
 

Susquatch

Ultra Member
Administrator
Moderator
Premium Member
My experience is prolly worth what it's gunna cost you.

I have over 70 years of shooting with everything from open sights to scopes to archery. My eyes are crap now, but I still have an excellent eye for centering and leveling things. Compensating for parralax is second nature to me. To this day, my bride still marvels at how perfectly level everything I do is.

Sometimes I will scribe lines and sometimes I don't. I usually center by eye and set offsets with a scribe on dykem. If I scribe a line, I can use a sharp center punch set on the line with my good eye and give it a light tap. I follow the light tap with a heavy punch the same way others have described it. For intersecting lines, I shoot down both lines visually till I'm happy and then tap and punch as above. I've never been able to see anything off using a jewellers loop. It's a bit unconventional, but if you do a lot of shooting I bet you will find it just as easy as I do.

That all said, I'm keenly interested in getting an optical center. My eyes are not getting better and I'd rather deal with it now than later.
 
Center punch it a skill that can be learn, it also an art.

The trick is scribed lines act as the catch for the point of a sharp punch, second scribed line is the stop, first is the guide. Come in at an angle rotate to vertical, tap sets the initial locate, check for equalness and do the deep punch. If not correct with a direction punch.
 

Mcgyver

Ultra Member
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.
 
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