you probably dont care but does any of you know a way to log back into an Instagram account?? I somehow forgot my login password. I would love any tricks you can give me!
Thank you so much! Because of this video, today I was able to recognize a Wild T3 theodolite buried in the back of an antique shop in central Jakarta! I had never even heard of a theodolite two months ago. Now I own one. _Next_ I need a dividing head I can test for accuracy. Once I have the dividing head, _then_ I can justify a mill. My life has direction again.
:D awesome story! And a T3! It was the most precise field theodolite of the era made by Wild Heerbrugg. To my best knowledge, the T3 was only used for ultra-critical work. Good luck with it.
LOL I would be inclined to think the same thing. Theodolites were not only a land surveying tool. Because of their precise nature, they were used in manufacturing shops to precisely locate things such as large fixtures and jigs or the parts they held for example. Often used in aerospace and power generation applications etc... As an equipment operator I would often assist surveyors and engineers in the field where they would use a theodolite when they wanted better positional accuracy than the transit would allow. (usually setting some piece machinery in place) It is a beautiful elegant instrument, one a mechanical minded person can appreciate.
I’d love to see a series of videos with you and Stefan Gotteswinter having casual conversations about concepts like “pretty good”, “not to shabby” and “perfect, at least.” It. Would. Be. Amazing.
Sunday morning, up at the lake, having a coffee, life is great! Why is it then that this video makes me wish that I was 3 hours south, at home and in my shop? Awesome video Alex. Thanks to you from a very humble Canadian. Cheers.
I found a US military study that determined *field accuracy* of the t2 to be +/- 2,15 arc-sec over a large number of readings on targets about 12-15 km away, using a 125 mm illuminated target... apps.dtic.mil/dtic/tr/fulltext/u2/642295.pdf One of my best friends had a Moore divider 1440 (+/- 0,1") and autocollimators, I think a T2, and a Geneva jig borer (with laser interferometer "DRO") in his basement...you would have liked to play there...
Given the sinusoidal error, I think you find at least some of the error is due to the axis of the T2 not being coincident with the axis of the dividing head. Try doing the same test, but sight on a close target instead, say 2-3 m away. This will magnify any lack of concentricity. An excellent textbook on this type of measurement is “Optical Tooling” by Phillip Kissam.
Or simply mount a rifle scope on the dividing head with the former's axis in line with the latter's face, and have the scope pointing at a target at a distance say 10 yards for an MOA scope or 10m for a MIL scope. Values can then be extrapolated by simple maths. Of course a better way would be to use a rotary encoder with even finer resolutions.
There are two errors to consider in the use of the Theadolite. 1rst error as you mentioned is machine error. This is the circle indice accuracy. Also not being absolutely perpendicular/level to the circle plane. 2nd error is user error. This is called parralax. Parralax is caused by the the angle of the human eye looking around the stadia. A learned and experienced surveyor knows how to move the eye and head back and forth (left to right, right to left) to zero the parralax error consistently. During my training, I was amazed at how much angular error can be intruduced by not limiting parralax error to a minimum.
That theodolite is a beautiful machine, and so is the dividing head. Very interesting stuff. I can't get enough of this workshop-geometry type video. Thanks, Craig
An obvious sinusoidal pattern with one extreme outlier. The sine wave would be from manufacturing error from one of the process machines at the theodolite factory. The extreme outlier would be from a wear pattern from improper usage or assembly damage. I've used a laser collimator for reflecting telescopes to project a beam onto a remote target, measure the offset, then calculate the error. Providing sub arc-second capacity!
I think those instruments came from nearby Dornbirn, AT, nicht Wahr? Are you from CH or AT, oder? Nice test! A friend of mine had a Moore 1442 precision divider, which would have been a nice comparison tool...and, yes, the lack of backlash in the adjustments is wonderful!
I would be very interested to see what the index errors are using the index plate and worm dividing function of the Walter. The direct index function utilizes a straight pin in the index plate which would account for the errors in your measurements albeit very good for a shot pin arrangement. All the best, Tom
Hello Tom, wow, thanks for your kind comment. I'm following your channel for years now and have probably seen 98% of your legendary video publications. Anyway, a precision test video of my Walter indirect indexer is coming up, since I'm currently reconditioning the worm drive (regrinding the worm is shown in my most current video). All the best from Austria, Alex. PS: I hope you did finish the Zirbenschnaps which I sent you a few years ago. ;) The guy who produced it meanwhile had his boiler burst during a live show (luckily no one got hurt).
@@anengineersfindings Hah! I may have the only remaining bottle (partial) of Zirbenschnaps in the west. I think it's value just went up. Looking forward to seeing the next video installment. Cheers, Tom
Nice work! Wonderful instrument. The Wild T2 is my dream theodolite (I have to make do with Zeiss/Jena Theo010s at the moment)... Plus, fun fact: sin(1") = 1/206264.8 which means on a 75 mm radius index circle, 25" corresponds to 9.1 μm offset. So, after 1 full revolution, the indexing pin locates again to better than 1/100 mm (which could be due to a bit of play because of an oil film somewhere being pushed one way or the other).
Very good point, thanks! The UTA100 has an index circle diameter of 95mm, so the positioning error at the pin must be even smaller than the 9µm you estimated.
I worked for an engineering firm 50 years ago as a rodman, and that is the same theodolite we used, the civil engineer referred to it as a transit. I enjoyed the video, and i did not realize how delicately accurate those instrument are, cheers!
An interesting method and not one I would have figured out on my own. I could be wrong but I believe Theodolite is a fairly old name for the tool and was/is used mostly in Europe. Transit would be a more modern term that seems to be used in North America. I've only heard them called transit's here in N.A.
@@turningpoint6643 Though transits and theodolites my appear similar in function (they both measure angles), they are very different instruments. Transits are like a yard stick and theodolites are more like a micrometer. While yardsticks and micrometer both provide a means to measure an object, they do so with vastly different levels of precision. The same holds true of transits and theodolites. Transits have been around much longer than theodolites. There's nothing modern about them. While transits are still used for crude work by contractors, theodolites have been replaced by total stations which are far more capable.
I own a 1955 T-2, previously used by Lockheed to build airplanes. I bought the instrument for boundary surveying and construction surveying in 1975. Unbeknownst to me the instrument was dropped in the early nineties. The horizontal brackets were broken. Do you know of someone who restores the T-2. Thank you.
@@anengineersfindings It is very kind of you to respond to me. I have been out of business for more than ten years. It is such a beautiful instrument, it was the first major purchase that I made and I would just like to have restored and then added to a collection somewhere.
I am curious now as to what, if any, features possessed by this specific theolodite are different or more accurate than others. I can grasp what I see now, but I am probably never going to find either of these tools. In my experience, stuff like this is kind of near impossible to find in the States. I often look abroad to find high precision manual tooling for my work. Any thoughts on what features an "obtainable" non-hyper specialized theolodite needs to have to duplicate this? I've only seen the things on large stands for surveying use, never anything compact like this. Now that I get how it works, could you use one in reverse- to manually adjust machining to be more angularly accurate? This is why I love your channel- you test accuracy as the main goal. Most people have never seen anyone do what you do.
There are toolsellers in the Netherlands I regularly check, and check Ebay globally. It's not easy to find things of such nature, agreed. I always find them when I'm broke 😥
Alex, that was a surprise, an interesting one. I will be watching for the manufacture of that worm gear. Which of course would be made easier on the repaired external drive deviding head! Ask ToT for a use of his time travel device, sorry, I digress. That theodolite is a work of art, thank you for showing it off, and it's travel case. I shal be on the look out for one...
Excellent presentation and analysis. I assumed you would use some optical method to check angles, but that theodolite is a thing of beauty! I feel,like it deserves a video just about it! And Gons are new to me, have to add that to my list of obscure units.
Hi, Alex. Wow, what a find! My dad (1931-2009) worked at WILD Heerbrugg for many years in the prototype department. And, among other machines, on a MIKRON milling machine.
Hello Guntram, wow, how amazing. Don't ask how much I would have liked to get a glance of the workshop your dad worked in, back in the day. All the best!
Great video some how I missed this video of yours. Now I need to buy a T2. On one of my many trips to Antarctica and South Pole There was the crew assembling 11 meter telescope mirror which is made of 100-200 approx sections. Each section was adjusted and calibrated with a centrally mounted Theodolite.
Wow, a spectacular working place! Some months ago I was involved in rigidity testing a huge roller spindle for the pitching actuator in radio-telescopes. The customer told me, the type of telescope they also installed in Antarctica. Must be an adventerous place!
Hiya Alex, Melbourne Australia here. I'm 53 and manufacture electric motors, can do nearly anything, but I had never seen how a theodolite worked before. I looked at Halley's Comet through one, but always wondered how they work. Now i'm that much smarter, thank you for a really well made video. Top work, as we would say around here. Subscribed too. Sincere regards, John.
Thats a cool way of checking accuracy! Ive got a T1A. And its divisions are in degrees. I dont think its as accurate as your theodolite. Keep up the great work. 👍
Thanks for the memories! I was an instrumentman on a geodetic survey party with the California Division of Highways in the late 1960s to early 1970s. I used a Wild T2 and T3, Kern DKM3, Askania 3E theodilites and AGA model 4D and model 6 geodimeters. Looking back now, fifty years later, 'mountaintop-to-mountaintop surveying were the best years of my life.
Wow, thanks for your interesting comment Mr. McLelland. Frankly I must say I envy you for your experiences in this job at that time. It seems my father did the similar thing over here. I really like to listen to him telling how they did it back then, with the AGA type 6 geodimeter that was larger than Arnold Schwarzenegger's back and everything had to be carried per pedes to the summit. In his last years at the surveying job my father suggested to call in for help with transportation. It was granted and his film [unlisted, here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-5L8X5edrWL0.html ] gives glimpses of their fantastic time. It is in German language, but I've added English subtitles. All the best and thanks for getting in touch.
@@anengineersfindings Alex, I pulled your email address off your channel after subscribing. Send me a reply if you receive it and we can keep the discussion going. All best, Carl
Got me! Turned out that my worm gear wheel is worn, my indirect accuracy is roughly factor 3 poorer than my direct indexing accuracy. But I spared this information for a potential part 2. "Dividing Head Worm gear manufacture" or so.
@@anengineersfindings That I would enjoy seeing. Machining a new worm gear for that dividing heads original accuracy specification in a home shop wouldn't be easy. I suspect the better ones are hobbed, ground, and then lapped for the best precision.
Just the next day after watching your video, I found one almost exactly the same on a local web-classifieds. It is a slightly different model I believe, marked WILD Heerbrugg RDS-245678.
Fantastic method for checking the dividing head! The one thing I'd suggest changing on your technique would be to aim at the *corner* of one of the barn windows, laying the crosshairs along the edges, rather than trying to choose a center point in the window. I learned surveying in college using a degree-reading T2, otherwise very similar to your instrument.
Thanks for your interesting comment, Sir. Whats not visible in the video is that the windows have internal framing (i.e. each window consists of four smaller windows). I used the framing as a nice target for the crosshair. Otherwise I would have used the edge of a window, like you suggest.
Actually centering the cross hair in the white box of the window is very accurate. I use T2 and the larger T3 for indoor metrology. At close range a sewing needle works well.
In the T2, the reason the two readings (standard and reversed) are slightly different is the collimation of the cross hair in the scope. It can be adjusted, but when it’s small it’s harmless as standard and reverse are always read. That collimation error is completely accommodated by averaging direct/reverse readings. Note: a T2 doesn’t need a calibration sticker. Proper operation always returns accurate measurement.
Wow, this was really great. And it raised a few questions and comments to be made. 1. You checked and adjusted that the axis of rotation of the divider was perpendicular to the plane of the theodolite. Isn't it equally important to check that the two axes of rotation are coinciding besides using the centring bushes you used when mounting the instrument to the divider? Or did the distance of your target across the valley negate the possible error? 2. I have always kind of wondered if a theodolite could be used in place of an autocollimator for machine tool or granite plate flatness measuring purposes. I guess that 0.5 arcsecond graduations are not fine enough but maybe modern theodolites have finer resolutions and accuracy. But what about the optics and the accuracy obtainable from targeting from a small distance such as within a room or building, say less than 50 meters? I've been told that theodolite accuracy diminishes as the target get's closer to the instrument. What do you think? 3. I have worked with a land surveyor friend in the past and had the privilege of operating a Leica electronic theodolite for a few days ( i think it was considered a total station, it had distance measuring feature incorporated to it, but no gps) and boy what a beautiful and precise instrument it was, and user friendly. I 've also had my hands on a Japanese Topcon unit and you could tell there was a difference. 4. Now I know the next time I'll be touring around the beautiful Austrian valleys (the route from Brenner to Innsbruck is probably one of my favourites) I won't just be looking out for beautiful scenery but also for great home machine shops. All the best, Dimitris
Hello Dimitris, to 1.: The point here is to target something far away. The error in angle due to axis excentricity becomes negligible then. 2.: I wouldn't see why a theodolite should be less precise on short distances. The angles you measure are the same. But not all theodolites are able to focus on short distances. My T2 can focus on 1.2meters (!) minimum. I'm sure you can use it for autocollimator work, provided you make a suitable sliding base for it.
