Optical Center punch

[Tin Falcon]

Success finally
As many of you know an optical center punch of the Mark on type as sold by Enco and others is a great layout took. this especially goes for those of us who do not have a DRO on the mill. these critters sell for around $40 and up these days.
Manny moons ago I decided to make one. Easy enough I thinks. Well made the body and the punch with not problem but a couple attempts still left me without a usable magnifier.
I am not sure what went wrong I even found a reference on optics and did some calculations. I used polycarbonate for the lens they make safety glasses out of it so it should work.
At some point I bought a piece of Lucite rod from Enco and it has sat in the stock rack.
Well last night I took the rod lopped off a piece and made another attempt to make a lens no real measurement for the length and eyeballed the lens radius.
Well low and behold I now have a shop made working optical center punch the lens is not perfect I may tweak it some but it works well enough to use.
Seems like sometimes a project has to age a bit before it wants to be finished.
Tin

 

[ksouers]

Congratulations Tin.
I agree, sometimes letting things ferment makes everything come together. You can't force creativity, each solution has it's own timetable. It'll let us know when the time is right, and not a moment sooner.

 

[wareagle]

Outstanding! As the old saying goes, never give up!!

 

[CB750k8]

Success finally
As many of you know an optical center punch of the Mark on type as sold by Enco and others is a great layout took. this especially goes for those of us who do not have a DRO on the mill. these critters sell for around $40 and up these days.
Manny moons ago I decided to make one. Easy enough I thinks. Well made the body and the punch with not problem but a couple attempts still left me without a usable magnifier.
I am not sure what went wrong I even found a reference on optics and did some calculations. I used polycarbonate for the lens they make safety glasses out of it so it should work.
At some point I bought a piece of Lucite rod from Enco and it has sat in the stock rack.
Well last night I took the rod lopped off a piece and made another attempt to make a lens no real measurement for the length and eyeballed the lens radius.
Well low and behold I now have a shop made working optical center punch the lens is not perfect I may tweak it some but it works well enough to use.
Seems like sometimes a project has to age a bit before it wants to be finished.
Tin

 

[compound driver 2]

Never found a need for an optical center punch. If your scrive lines are visable and evenly deep and the center punch ground correctly the tip of the punch should drop into the cross formed by the scrive lines.

 

[Maryak]

Tin,

Good news on the centre punch. Just shows again that genius is 10% inspiration and 90% persistence and perspiration.

Best Regards
Bob

 

[itowbig]

ok so where are the plans for this : & lets not forget the all important pics ;D
yes were a finicky bunch ;D we got to have our pics ;D

 

[minerva]

hi all,
for anybody who aspires to the making of an optical punch may I highly recommend
a visit to John Moran's (aka gadget builder) site where all is revealed
http://www.gadgetbuilder.com/index.html

I am waiting for delivery of some silver steel to complete the punch side of things.
The optic, following John's advice proved to be relatively straightforward and the first attempt produced a successful result ( see attached photos ). I will say that I used a ball turning tool (again one of John's designs )
to achieve a 9/16 Radius on the optic. If any one particularly wants any dimensions just shout.
Kindest Regards.

Terry t

ps sorry for photo quality I really must see if Santa can help out ( new camera hint hint! )

 

[dparker]

Hello All: I made my optical center punch a few years ago after reading a article in HSM or MW.
I used a piece of clear 1/2" Dia. acrylic rod (from Tap Plastics) and squared off the working end and turned two very shallow circles into the end. The other end was filed to a slight crown and the both ends were polished with a plastic polishing compound. A cotton ball was used to hold the polish and I kept rotating it to help form and polish the crown.
The first one I made had too much magnification so the second one was a much shallower crown. The block is made of aluminum and would do better if I get around to gluing on some gasket material or thin rubber sheet on it to keep it more stable from slipping on the parts.

The amount of light going through the rod is surprisingly good enough to be able to see quite easily where you are, and the circles do a good job over a center punch or scribed line intersections.

The pictures are taken on a tablet of 1/4" per square paper if anybody is interested in the dimensions, although this could be made to any dimensions desired.
don

 

[John S]

To stop mine slipping it has a groove in the base with an 'O' ring super glued in.

 

[black85vette]

Anyone else use one of these? What are your thoughts on them?

 

[John S]

Brilliant,
I use mine about as often as I use my white stick.

JS

 

[Maryak]

black85vette,

This topic is already here - http://www.homemodelenginemachinist.com/index.php?topic=3290.0

At the top of the page is a search function. If you enter your search parameters when you are looking at the index [HOME]. page this will search the forum. Elsewhere it will only search within the board you are looking at.

Best Regards
Bob

 

[David Morrow]

I love mine and use it all the time.

And to hell with the search function. Whenever a new guy asks a questions, the old guys just point to the Search function. Ask old questions and get a whole new set of answers is my opinion. The search function is useful but it can stifle new discussion on old topics.

 

[Blogwitch]

David,

Rather a bold statement.

And to hell with the search function.

And deny the newcomers the mine of information from previous discussions. It doesn't stifle, but enhances, as new discussions might not have the same knowledge base available as previous ones.

http://www.homemodelenginemachinist.com/index.php?topic=2870.msg32704#msg32704

http://www.homemodelenginemachinist.com/index.php?topic=661.0

Topics should be expanded, not restricted as you suggest.

By just using these two examples, it might resurrect old posts or stimulate further discussions.

The search function is the most important feature of any forum. Allowing access to a wealth of information, rather than who is on line and interested in the subject at this moment in time.

Blogs

 

[Maryak]

Blogs,

I have been pondering on the best way to respond to David Morrow's post. You have done it much better than I could have. :bow:

Thank you and Best Regards
Bob

 

[black85vette]

Thanks. Actually I did search before I posted. Been around forums (and bulletin boards before that) for some time now. The other posts dealt with using the punch and making one. I was more interested in a general discussion of how commonly they were used and different views on them. I found it interesting that one of my best friends has been a machinist in a tool and die department for 30 years and had never seen one until I took mine over to his shop.

So, back to the discussion on the optical punch.

 

[Metal Mickey]

I wouldn't be without mine! It really impoves my ability to centre punch on the mark required. Buy one, you won't be dissapointed. Mike

 

[BobWarfield]

I'm with David. Telling newcomers they have to search instead of answering their question is something those "other" forums do all too often.

It implies the newcomer is wasting your time by asking the question. If a friend asked me a question I knew the answer to, I would be very unlikely to refuse to answer his question and instead school him on the use of Google. If a friend gave me that answer, I'd consider it rude and he'd better be pulling my leg.

And, as black85vette pointed out, he was already familiar with search and had used it.

Best,

BW

 

[PhillyVa]

How about giving an answer and a link for more info...that would work for me.

Regards

Philly