Optical measuring experiment.

For many years I had the use of a Baty Shadowgraph and wishing to replicate the ability to accurately measure form tools etc, I decided to see if a home version was possible.
A free cross-hair program can be downloaded written by Mike Lin, link https://download.cnet.com/CrossHair/...-10561218.html and is a screen overlay which works with any application either floating or fixed and as a mouse pointer if wished. NB it is always a good idea to check any downloaded programs files for malware etc before running them.
A fairly cheap Andonstar pen microscope is mounted in static position and connected to a USB port, all measurements are recorded by machine movements lining up the cross-hairs on screen, easier for those with DRO but I have used a temporary digital tyre gauge so far to keep original reference position. This also replicates a system I used at work using a VGA camera and monitor when turning complex face forms in hardened steel punches for shock absorber valve tooling.
I have tested the set up in various ways against known sized tools and have agreement in sizes. Useful to measure the flat on acme tools, and on the lathe centre line to measure O ring groove diameters and the front edge of internal taper bores etc at about a 50-1 ratio and am pleased enough with results to make some proper mountings to replace the cobbled up test ones. Obviously handy to check the true sharpness of tools and taps etc, and dare I mention splinters again.

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Jon, Oh Jon; paging Mr. Jon R.....
Tool of the Week winner right here.
You're welcome.
Sincerely,
HMT.net Telepathic Message Service

PS I don't know about Olderdan's life offline. Never heard anyone doing portraits of splinters, no matter how significant....

Olderdan this really interests me. I'd seen USB video scopes; but affordable versions had questionable focal distance and real narrow field of view. That was quite sometime back and I dropped the quest. It's back ON! The interest was piqued by how superior optical measuring can be compared to any electronically interpeted scale. Anybody remember the Bridgeport Optics, achieved real .0001's very reliably. That's beyond a real expensive DRO getting .0005's or .0002's and still question resolution AND repeatability.

I'm with TM51 this is a superb implementation of DYI Optical measurement for <$100 ($65 camera plus misc). The cross hair is great on that ID/OD setting/measurement. I'd be interested in creating graticule's some how. Perhaps transparent PNG or better TIFF files...although based on pixels it would be something I might try. They might be created in ACAD as vectors then brought into Adobe Illustrator and ported out from there as PNG's or TIff's. I'm sure you could achieve at least a thou in resolution. I would need to try the MSI for the crosshair program and see how the Webcam driver works with it...I know that some Logitech camera software will allow green screen type overlays.

Bravo Olderdan!! Well Done! Thank you for sharing this great tool with us. Got my juices flowing!

Jon, this has my vote for TOW also.

Quote:

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Originally Posted by PJs

I'm with TM51 this is a superb implementation of DYI Optical measurement for <$100 ($65 camera plus misc). The cross hair is great on that ID/OD setting/measurement. I'd be interested in creating graticule's some how. Perhaps transparent PNG or better TIFF files...although based on pixels it would be something I might try. They might be created in ACAD as vectors then brought into Adobe Illustrator and ported out from there as PNG's or TIff's. I'm sure you could achieve at least a thou in resolution. I would need to try the MSI for the crosshair program and see how the Webcam driver works with it...I know that some Logitech camera software will allow green screen type overlays.

Bravo Olderdan!! Well Done! Thank you for sharing this great tool with us. Got my juices flowing!

Jon, this has my vote for TOW also.

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PJ's intercepted my brain-wave postage to Jon, lol. But half is beyond my interpretation of terminology, the gist is clear though. I've spent countless hours measuring at optical comparators. Registering a part [set-up] is like machining, to check as many features possible according to a single datum.
I want one. I want one. I want one.

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Thanks olderdan! We've added your Optical Measuring Tool to our Measuring and Marking category,
as well as to your builder page: olderdan's Homemade Tools. Your receipt:

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Thanks guys, this was fun to do and a bit of light relief from doing house renovation all summer.
The main reason for me exploring this idea is that I do a lot of motorcycle restoration and make or convert parts to O Rings where possible. Problem is hitting the correct Dia in the face of components, O Rings are fairly forgiving but work best if done right, now I can scratch cut where I think is the correct dia, measure and compensate.
The camera has USB or VGA Webcam options, and uses a free program called Amcap and also has video capture. I just use Gadwin PrintScreen for stills. I am sure there is an app for smartphones but I have no use for them. The odd thing is part of me wants one but most of me hates them.
Regards
Alan

Wonderful idea, Olderdan. Thank you for sharing here and starting the gestation of more ideas to come. I can see this developing into a very nice poor man’s CMM. I have reviewed all of the software mentioned to-date but have not had the time to download and run any of it. It appears Cross-hair’s latest OS was XP.

Since I reverse engineer devices I need positional data not only on prismatic and orthogonal features but, most importantly, hole locations. Again, I have not downloaded it yet, but it appears Cross-Hair may be problematic regarding hole locations. Trying to find the center of a hole with a cross-hair can be tedious and error prone. I guess you could “shoot” all 4 sides and divide by 2 (or 3 sides once the middle of 2 sides is established). However, circular and angular reticles would make it a full functioning instrument. Your adaption of the camera and software is too important to ignore and like others here, time permitting, I will continue with your idea and post to this thread. It’s exhilarating to see where this goes.

Years ago I bought this SPI kit for the drill machine operators and the 5 reticules it came with had every thing necessary to QA samples from the machine. When developing the drill machines I had access to a 48" Mitutoyo CMM for dialing in the angles and profiles and that was the cats meow, but the idea of creating reticules/graticule's for this optical system seems doable. If not through transparent Gifs or tiffs possibly through purchasable glass ones (although not cheap n' cheerful) like above, mounted external of the camera lens. The diameter of that camera is pretty small (12mm) though for store bought. Typically they are from 16mm up and pricey.

re: PJ's comparator reticules

Quote:

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Originally Posted by PJs

Years ago I bought this SPI kit for the drill machine operators and the 5 reticules it came with had every thing necessary to QA samples from the machine. When developing the drill machines I had access to a 48" Mitutoyo CMM for dialing in the angles and profiles and that was the cats meow, but the idea of creating reticules/graticule's for this optical system seems doable. If not through transparent Gifs or tiffs possibly through purchasable glass ones (although not cheap n' cheerful) like above, mounted external of the camera lens. The diameter of that camera is pretty small (12mm) though for store bought. Typically they are from 16mm up and pricey.

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Correct glass screens cost; with limitations of usability. What I recall is most are sized for certain magnification housings [6 to 72 inches], are unmarked and not clear but frosted. I'll suggest the plastic overlay charts. Far lower cost and marked with standard scales for diameter, linear distance, angularity, thread forms. At the federal plant, they made specials on site with a FINE penned plotter, or even manually with what amounted to a backlit drafting table. Pens were just like Koh-I-Noors, a small vertical microscope that stood on a base [IIRC 100x] and he drew them. They were drawn full magnification size, had comparators from 20 to 50 power.

Here is one of such suppliers, I'm not familiar with them. I have a 12" Micro-Vue desk comparator, and a lot of charts came with it from auction. Gauging my win, pricing this size didn't seem prohibitive. I've seen them on you-know-whobay too. Playing with Microsoft Paint, and using pixel-oriented coordinates, they can be printed DIY on clear plastic sheets ala office supply stores.
Plenty cheep 'n cheerful.
Unlike Zeiss CMM's, optical comparators, multi-sensor systems and metrology software the web monitoring program of this page hypes in advertisement. Lol.

PS. I think reticle/ reticule applies to a marked glass, [ie combining the glass and chart] and what Olderdan and PJ's seek may be the overlay, aka chart.

Comparators, vision systems and CMM's are great yet limited to a platform of some type and have size limits. The true beauty of OlderDan's system is being able to mount it to a cross slide, tail stock, mill spindle, etc, for in process/setup work on the machine and even for inspection after...maybe even a DRO of sorts.

A number of years ago now my son with a little help from his dad designed and set up a QA vision system for measuring stent tubing off the extruder. Biomedical devices are hell on wheels about QA and must be Qualified with all the I's dotted and T's crossed. His system was finally qualified and ended up saving substantial Duckets annually. His trick was using excel (my help) as the data logger and qualifier working at 5 decimals, rounding to 4. As I remember the cameras/software had some sort of built in graticule systems that were customizable, or selectable from the software. I'll check with him to see what he remembers. Overall the system had a 4 mo. ROI and virtually no maintenance...Cha Ching for them and Chief feathers for my son.

by setting the camera on the cross slide you could use it to " measure "existing parts. It work great on a lathe that was equipped with a DRO. You could do the same thing on a mill by mounting the camera on the head.

Tying measurements to what produced them is logical. Measuring via camera [physically viewing] very dependable, providing aim is at correct feature.
But my preference would attain verification using something not dependent on same instrument; ie gauge rods with micrometers.

I was thinking about measuring something you were trying to make a copy of, for instance a mill collet.

I often need to make parts that bolt to something with an odd bolt pattern. I could lay the existing part on the mill table and use the camera and the DRO to measure the location of the holes in relation to each other or some conmen reference point. I can do the same thing with a dial indicator mounted in the drill chuck but it's a pain.

Quote:

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Originally Posted by skypilot

I often need to make parts that bolt to something with an odd bolt pattern. I could lay the existing part on the mill table and use the camera and the DRO to measure the location of the holes in relation to each other or some conmen reference point. I can do the same thing with a dial indicator mounted in the drill chuck but it's a pain.

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Understood. You are correct, a mill can sub as a coordinate measuring machine. The meaning of my post is checking a part, a little different than reverse engineering. It all hinges on selecting correct reference datum, determine tolerances, and utilizing that to produce either a twin or modified as intended.
But good as optical measuring is, software or properly handled mathematics are only guarantee of success.

All good points of use for Olderdans system and agree that hard measurement is still a foundation for in process. To me it's not about making his system into a "All seeing" end all to producing things on the mill or lathe...the point is getting the most out of a cheap and cheerful build, cheap and cheerfully...ie., not trying to build a CMM or high end vision system but something that can be used regularly for lots of ops and even some rudimentary QA with relatively good resolution...for lots of HMT's folks and others.

I checked with my son and his system did use an x-y table as the parts were tiny and needed 2 views (length profile & Cross section for ID/OD) with datums to measure and record. The software used a crosshair with feeds from the x-y coordinate table and push buttons for datum and measurement recording. So that's not going to work for this, imho.

I still think a Gif/PNG or Tiff reticule/graticule might be doable...but would need to spend some time with it...something I'm a bit short of for the next while as a big video project just dropped in my lap along with about 6 other large things going on. I'd be more than happy to generate the Gif or Tiffs if someone wants to help figure out how to use it with the cross hair or stand alone, then test them. When I get a few or in need a fun diversion, I will try the crosshair program...its an MSI install and don't know the details of how it ties in with webcam drivers but could see.

Love the idea of this! Inspiring OlderDan, Thanks again!!

PJ

I will echo everyone else on the nicely done implementation here. Very handy. There are many USB microscopes out there now for very reasonable money that can put this capability within the reach of pretty much anyone who wants it. I messed around with this concept a bit some time ago but never really went all that far with it. May have to revisit that now. I do have an old machinists microscope with an x-y measuring stage, perhaps it needs a camera now...

Related to some of the other discussion here, there are a couple of other software packages that some of you may want to check out that have application here. One is called "MICAM" and can be downloaded for free here:

Science4all - Microscopy and Photography

This allows you to do all sorts of related stuff like add calibrated scales to your images, relate pixels to real world measurements, do measurements on your images and such. It takes a bit of messing around with to get used to it, but can do quite a lot for a free SW package.

Another is called "ImageJ" and quoting from their website:

"ImageJ is a public domain Java image processing program inspired by NIH Image for the Macintosh. It runs, either as an online applet or as a downloadable application, on any computer with a Java 1.4 or later virtual machine. Downloadable distributions are available for Windows, Mac OS, Mac OS X and Linux."


It was developed initially by the US National Institute of Health and is in the public domain for anyone to download and use. It has extremely powerful image processing capabilities but the caveat is that the learning curve is quite long. It is mostly useful for captured images so not quite as good for real time "comparator" type stuff but I figured some here might find it interesting. You can read about its capabilities and download it here:

https://imagej.nih.gov/ij/docs/intro.html

Anyhow, just some FYI and thanks for sharing your work!