I have an older T-3 in almost great condition. The only problem is that the micrometer needs to be adjusted, or otherwise it's a paper weight.
The micrometer sweeps 0-60 nice and smooth. However it about 2 seconds short. For instance, when I zero it on any one minute and then rotate the micrometer to 60 the index marks are not yet lined up. So it needs to be adjusted. I've used Wild instruments for a long time, so I'm sure of the problem. I'm hoping that the adjustment is readily accessible.
Q: Can this be done easily or is it an expensive, hard to do servicing? If it's hard to do safely, who still works on T-3s?
I haven't found a manual that addresses micrometer adjustment, although there must be tons of docs on the subject.
Larry
Larry: try swisstek (www.swisstek.com).
Call Earl Huegenel at Gulf Instrument Service - (504) 733-4853. He used to work on a ton of Wild theodolites and if he can't do it he'll tell you that.
@larry-scott Understand that this is a really old post but curious how you ended up? If I'm understanding correctly I believe I have the same troubles and am hoping to do the adjustment myself to save on travel. See the image below.
@dave-ingram Curious if you have any advice? Would be much better and less confusing if I could align/adjust a little more than a minute out. See the image. btw. the image is made available from the battery box and light I purchased from you last year. Thanks for that. 🙂
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Are you talking about the index line? being off when you rotate the drum to 60 seconds?
If its the index line that never lines up that is a easy fix.
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JOHN NOLTON
@john-nolton Yes, exactly. That index line is so close to the 2 minute mark that I'm afraid I'll make a reading mistake. Same trouble on the vertical circle as well. See this image below. Any help you have would be greatly appreciated. I've combed through all of the manuals I can find.
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in your pic the index is just offset. Learn to live with it. I think all my guns are like that. I read across the top and across the bottom. And you get good at figuring it out. And yeah, you bust ?ÿa minute, or 2.?ÿ
My problem was the micrometer sweep was less than the 60 units (120?, I have old 60 unit micrometers and the micro reading has to be doubled. Yeah old school.) So what I had was a scale error of over 1? per minute, 2? overall, and nearly unusable because the micrometer would not reach coincidence in either direction too often.?ÿ
I??m militant on micrometer scaling errors. All my guns have a couple 1/10s of a second per minute. And I always use set procedures to allow for prorating the micro reading. Which T3??s saving grace is a 120? micro sweep. A degree T2 with 600? sweep, prorating micrometer scale error is the difference between 2-4? and 1? accuracy. My Mils T2s have a 1 mil micro, a 202.5? sweep, 1 mil is 202.5?. And I find 1/2?(+/-) error if I don??t prorate the micro reading.?ÿ
Learnt that the very hard way. I often work in 0.1? SE at close range.?ÿ
The micrometer in T2/3 is a subassembly. I was able to find a parts gun and just swap it out. I wouldn??t mess with your micro based on your pic. That??s normal for Wild. My guns ain??t special, yours looks typical.?ÿ
note: he has a newer 120? reading micro. Not like the old guns with only 60 units.?ÿ
ok, reading across the top, your choices are 90-00 or 90-04 ?ÿ
acriss the bottom it??s either 89-56 or 90-00 ?ÿtherefore 90-00
i get that in mils: across the top I might have 3113 or 3114
Across the bottom 1514 or 1515, ergo 1514 because it??s common to both ?ÿ
all my guns do that. And if you use it often then it??s just something you get used to.
If it??s an easy fix, I??m all ears!!!?ÿ
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Larry Scott & along?ÿ sorry for not getting back to you on the question of the index line on the T3 Theodolite.
This is an easy fix. Please give me several days to set my T3 up again and to make sure I give you exact
directions since I have not done it in 20 years. Mine is in adjustment but I will take it out and put it back in adjustment and take good notes.
By the way this is one of the faults of the T3. It can go out of adjustment(index line) just by setting it down to hard.
JOHN NOLTON
John Nolton: that is interesting that you say it can happen so easily. I do have a T3, but never used this particular instrument in the field, I mainly just play around with astros here at the office. In the past I used a T3 to do 150 astro azimuths on a bluebook project back when doing a single observation with GPS was very costly, so we set azimuth marks with astro obs rather than pairs of points. Mid 80's.?ÿ
When I worked for the Corps, I always used a T2, older model in the bullet case. On one occasion working in WV (very steep hills) I set the bullet down, and it tipped over and started rolling down the hill, and ended up about 100 feet down crashing in to a tree. The only damage was it knocked the vertical out to about 4' on the split, easily adjusted back to spec.?ÿ
My current T2 lays flat in a hard plastic case. I was leery at first, I remember being told not to let the T2 lay on its side. But at least it won't roll down a hill. And it is well cushioned in the case.?ÿ
ive never seen the index change over time or with use.
Storing a T2 laying down is not a good idea. The lubricants in the main bearing can migrate.
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@john-hamilton?ÿ I was on a BLM crew where the instrumentman was passenger in a two man helicopter which lost power at low altitude and suffered a hard landing.?ÿ He was OK except for whiplash and some abrasions.?ÿ He had the T2 under his lap belt, which was unharmed.
The helicopter was severely damaged but both occupants walked away under their own power.
I just acquired a 1950 Mils T2. It??s a gem.
It had an optical plumb, and the leveling screws and does not have tribrach interface.
Compared to much newer mils T2 and the angles return the same Std Dev: 0.6?. (After accounting for micro scale error.)?ÿ
Mils T2 micrometer reads 0.002 Mils, and the spacing on the micro easily reads 0.001 Mils. which is 0.2?. So, the T3 gets a lot more shelf time.
I guess you are having trouble?ÿREADING my post Hamilton.?ÿPlease show me where I use the word?ÿEASILY.
What I did say is "setting it down too hard". Also I said nothing about the Wild T2 Theodolite.
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JOHN NOLTON
Yeah, John. I can read. When I say "easily" I mean just by setting it down "hard". That could happen anytime (trip and fall, etc). What I was pointing out with the T2 was the opposite of "easily", ie. rolling down a steep hill, meaning it is more durable (understandably so)
@john-hamilton?ÿ?ÿThe post is talking about a T3; not the T2
If you want to talk about the Wild T2 theodolite then start a post and I might say
something about it. The Air Force Geodetic Survey Squadron preference was the
Kern DKM3 theodolite over the Wild T3 (for good reasons).
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?ÿJOHN NOLTON
I also liked the DKM3, especially for astro obs with the broken telescope. But unfortunately I don't have one now. I think there are a lot fewer of those around.?ÿ
