https://knoba.files.wordpress.com/20...pg?w=300&h=225
Link source: https://knoba.wordpress.com/2015/07/...-centre-punch/
CAD file: https://www.dropbox.com/s/2qhmuuqipj...02015.dxf?dl=0
Thanks Ken!
Printable View
Nice tool, knoba! :thumbsup:
Thanks DIYer!
Pretty thing to look at and look into. Great idea on the crosshairs. Spot on!
Al
wow thats a nice punch eyeglass as good as mine. :O)
Thanks guys'!
Mornin' Cap!
There's nothing shoddy about your punch, mine just looks fancy in a round tobacco tin... ;)
i'm gonna get a tin toooo...:O)
Thanks knoba! I've added your Optical Center Punch to our Measuring and Marking category, as well as to your builder page: knoba's Homemade Tools. Your receipt:
<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="http://www.homemadetools.net/optical-center-punch"><img src="http://www.homemadetools.net/uploads/125880/optical-center-punch.jpeg" /></a></div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="http://www.homemadetools.net/optical-center-punch">Optical Center Punch</a> <span> by <a href="/builder/knoba_3">knoba</a></span> </div> <div class="tags">tags: <a href="http://www.homemadetools.net/tag/punch">punch</a>, <a href="http://www.homemadetools.net/tag/centering">centering</a></div> </div> </div> </div>
Knoba, Like I said I just love this thing and will be making one soon but realized you had a 17.8885mm spherical radius for your optics...how on earth did you determine that let a lone make it? I'll have to hunt for a tin though! :lol:
A really good and unexpensive idea !http://smileys.sur-la-toile.com/repo...prosterne2.gif
I'm not that smart! http://www.homemadetools.net/forum/i...milies/lol.gifQuote:
Originally Posted by PJs
The radius of the optic was set to allow for some manual adjustment, later by trial and error, on the lathe. The actual radius ended up somewhere near 9/16th. The optic was gradually altered until it appeared to give a good magnification without too much distortion. Only the top surface of the curvature of the optic needs modifying as needs require.
Sometimes I get stuck knowing where to start with a project (like with my welding turn table). My answer, to myself, is just to start it, anywhere, somewhere, the answers will define the questions that need to be asked.
Thank you for your compliments!
Let's not forget the pink packing foam. It was specially imported from China... ;)
**Have updated the cad file and changed the optic to a 14mm radius.
Thank you, Okapi, nice compliments, much appreciated!Quote:
Originally Posted by Okapi
Thanks Knoba, I get it about "just start" and that it would be a hunt and peck for optimum clarity and magnification...especially with trifocals. :lol: Don't have a ball turner for my lathe yet but pretty good with a graver. Thanks for a good starting radius and no worries about the foam...have a bunch! Need to look at your turntable again...but have to say, you are one Prolific builder!!
The simpliest you make, the most efficient it is and the more reliability you have, polycarbonate magnifying glass are the best unexpensive friend too for helping us after 50 years old… http://i44.servimg.com/u/f44/11/04/31/48/vieux_10.gif
Hi knoba,
Very impressive device! Your Optical Center Punch is the 'Tool of the Week'!
You'll be receiving one of our official HomemadeTools.net T-shirts:
Just let me have (via PM) your details (size, color choice, and mailing address) and we'll get things processed directly.
Congrats!
Ken
This thread has been moved to the Must Read subforum. Congrats (and thanks) to knoba for making such a valuable contribution!
Congrats Knoba! Simple and Elegant always a winner in my book!
Wow!
Thanks for the award & thanks for the compliments, guys! http://www.homemadetools.net/forum/i...es/hat_tip.gif
Hi knoba,
Don't forget to PM me your info and shirt selections (size & color)! We'd like to get it right out to you.
Ken
Nice one..
Hi knoba
I found your optical punch design on your website before joining HMT. I copied it right away and it has been my go to marking punch ever since. I have used a HSS punch and all acrylic for the rest and made two optics, one with crosshairs and one with a bullseye (this is my favourite) I even copied the storage tin. Many thanks for the idea and everyone should make one, it never misses the mark.
Attachment 20291
Well deserved award
Regards
Olderdan
Agree with olderdan, but can somone explain how to polish the acrylic lens ?
Acrylic is one of the easiest materials to polish, after removing any machining marks with 1200 grit wet & dry any metal polish (or jewellers rouge if you have any) hand worked will quickly do the job.Quote:
Originally Posted by Christophe Mineau
OK thanks, I think I had bad experience in the past, maybe I was too fast on the polishing disk, will try by hand next time.
Thanks !
In the trade, these are known as bombsights.
My optical center punch is commercially made, it's a long time 'friend'. I have no clue about the optic radius, actual magnification or focal length, but it must be relatively high.
I'm near-sighted yet cannot use it without eyeglasses, that would make the focal length at least 18". It's not crosshairs but a .003 dot, slightly wider than a fine scribe line. It will locate centers within .002 all day.
There is no reason to suspect knoba's is any less accurate, therefore a worthwhile project.
Hi Christophe,Quote:
Originally Posted by Christophe Mineau
You can found polishing paste for watch synthetic glasses which goes for cleaning and polishing all optical sights or protecting glasses in the workshop, the result is spectacular only with a clean cloth and some human oil… ;-)
