Gallery, Projects and General > How to's

PRECISE OPTICAL LAYOUT FOR CENTER PRICKING

(1/4) > >>

ieezitin:
Hello lads



Marking out center prick marks and getting them dead on center is always a challenge so I had a need to precisely mark out three holes for a master jig plate i needed and thought rather than bash out my pop marks and just go with buttons i would shoot for the size from the surface table and use my trusted optical layout and drill bushing set, old technology but works a treat, i thought i would show this for people who have not seen this done...

My plate blued and marked from the hieght gage and surface table..



A picture of the scope showing the cross-hairs, i positioned it on a 45 deg angle so it shows the black cross-hairs better because sometimes the scribe line will consume it..




shots of the scope laid out over the scribe lines...








once the scope has been zeroed in i take out the scope lens and install a drill bushing and a then slip in a 3/16 center finder punch and very lightly tap it.. this shot shows i removed the drill bushing and put the scope back in and it shows the very small prick mark..


 


here is what it looks like as normal ..

ieezitin:
I clicked the post too soon... here is the rest..

Here is a shot with the first prick mark, then i used a regular center prick punch to make it deeper, you can get a sense of scale..





Here are the tools i did this with...







I hope this helps people.


All the best Anthony...

DavidA:
Anthony,

Nice, but are you going to tell us where you get the cross hair optics ?

Dave.

ieezitin:
Dave

 i have had this setup since 1992 or so, they sell the same gear on ebay or any quality tool shop, i dont remember where i got it,  just google, " optical center scope" and you will find a supplier/vendor... i would suggest dont buy an inferior brand, invest your monies in a quality set-up from a known toolmaker supplier.

Hope this helps..

Anthony ....

Eugene:
By coincidence I elected to go the optical punch route a month or so ago.

I was advised to try and find a British made version by DanKroy. Unfortunately the company is out of business and the second hand ones are few and far between. So being a patriotic Brummie  with a shamrock in his turban I ordered a British made alternative and a right piece of rubbish it turned out to be.

The heart of these things is the plastic magnifying lens; in my case this was so badly formed that it distorted both the  straight scribed lines and the graticule making it impossible to align accurately. In addition the graticule lines were very thick and coarse, and actually obscured the lines on the workpiece. The single ninety degree punch had heat treatment scale still on it, the whole issue being supplied in a plastic bag. Binned it day oi?

Next up was the Soba version currently advertised at a discount from Axminster ...... absolutely excellent bit of kit; two precision ground crystal clear lenses, one with fine black cross hairs, totherun a dot, one sixty degree and one ninety degree punch, all in a nice wee case. Not sure of the ultimately available accuracy yet, I need a bit of practice, but guessing, it's single figure thous just now.

Unreservedly recommended at around twenty five quid including postage.

Eug

Navigation

[0] Message Index

[#] Next page