turning sets.

Keep back sights as long as possible .
Keep doubles under 15 sec
Check and adjust prism poles every week ,

Site as low on the pole as you can and then turn up to the prism.

Matt

If your looking for tight angles use plumb bob . Google it if your not sure what that is..

Never go past your target and then turn back to it. You will pick up any slop in the scales. If you are turning clockwise angles, stop just slightly to the left of your foresight and use your tangent screws to slowly turn to the right and center up your crosshairs. If you should go past the target, even by a little bit, turn the gun all the way around and try again. It will come easy with a little practice.

I will try all these things any and all tips are great im all ojt here . Learning as I go. Sets are not my string suit. If it helps any one im on a topcon east station 2 montha old

20" = 0.01/100

Always think about how close you can zero in on a target.

20" = 0.01'/100' (twenty seconds is a hundredth in a hundred feet)

If you have a sideshot 10' away and you are off by 20" then you are within 0.001' of your first turn. If you can do that every time, you are the luckiest instrument man on the face of the planet.

20" = 0.01/100

Good to know is there a chart I can find somewhere for that or a simple math equation. Also here in fl when it starts warming up we get bad heat waves through the gun . It becomes very hard to see the very center of the prism how can I be sure a my shot when this happens

Your tripod is the weakest link in the whole set up:

• Make sure it is firmly set in the ground. Asphalt is probably the worst, on a hot day.
• NEVER let ANYTHING touch the legs. Don't even let your shirt brush up against it.
• Always use a delicate touch when tightening the motions and turning the knobs.

Remember; you are dividing a circle, the size of a bar coaster, 360 times; then each one of those 60 times; then each one of those 60 times....

Try doing that with an old Gurley.....

> Never go past your target and then turn back to it. You will pick up any slop in the scales. If you are turning clockwise angles, stop just slightly to the left of your foresight and use your tangent screws to slowly turn to the right and center up your crosshairs. If you should go past the target, even by a little bit, turn the gun all the way around and try again. It will come easy with a little practice.

Never heard of that before; what exactly is meant by "pick up any slop in the scales". I was unaware that fine tuning the crosshairs from the right could reduce the aiming accuracy if turning angles clockwise. What is the reason behind it?

If there is any sloppiness or "slack" in the scales, they can be moved when you turn the instrument. As you turn the gun, the scale moves until the slack is taken up, the scale or sensor are then stopped at the limit of the looseness and begin the measurement. If you turn the gun back the other way, measurement does not occur until the slack is taken up again as it limits out going the other way. To picture this, think of a Master combination lock. You turn the dial one way, then when you go back the other way, it takes a bit for the mechanism to get picked up and turn. When you are dealing with those tiny scales doing the 360/60/60 thing, a little goes a long way. This was SOP with T16s and T2s. Not sure if electronic instruments are susceptible to this, but I've always done it this way with good results.

Thank you for the tip / explanation.

20" = 0.01/100

Chart?
Hit the Khan academy and get trigonometry under your belt. It's not too tough and it's the basis for so many, if not most, basic surveying calculations. You really need this skill.
As to heat waves, I've never heard of a good method for dealing with it. Planning your setups to avoid shots across asphalt and the like would at least help, hard to do in the City.
At Ft. Hood, TX we did a lot of surveying (Artillery) at night with lighted targets to avoid the heat.

I have just tried this 3 times on a pratice set and it seems I was geting a little tighter each time. Seem like good advice I do appreciate. How long does it take to be able to get it on ur first or second try everytime

TRIG CHART

Most of the trig you will need is based on this simple phrase:

SOH CAH TOA

Sin angle = Opp/Hyp
Cos angle = Adj/Hyp
Tan angle = Opp/Adj

TAN (0D0'20") * 100.00' = 0.0097' ~ 0.01'

The 20" is 0.01'/100' is easy to calculate.
You can easily run it to 1' (one-minute) is 0.03'/100'.

So tell me Mr. Jester,
You shoot a sideshot that is 150' away and you are off by 13", without a calculator and assuming your instrument is perfect, how imperfect are your two sightings?

I have closed traverses (large and small) between 1:3,000 (uh oh) and 1:>100,000 since I've been surveying. I average around 1: 80,000 no matter what size or terrain of the traverse. I've also found I can turn better traverses with the old Topcon than any robot can do. All you can really do is give it a good standard of care. For best results use 3 tripods. For a little worse result, use 1 tripod and 2 bipods. For the worst results, use only a hand held rod. For the worst worst results, use a tripod for the backsight and and hand held rod for the foresight. Also, think about how many sets you need to do. If a gnarly wood situation requires a long foresight from a short backsight or vice a versa, consider turning more angles on that set.

However, it really is all just up to fate. If you use a proper standard of care and something goes amiss, don't blame yourself or anybody else. It happens. Sometimes a busted traverse can happen from natural conditions such as heat, soft ground, extreme vertical angles, etc.

Most importantly, what do your state standards stress or your client? If you meet that, then who cares? Get the job done. I turned a set of 1:120,000 error. Guess what? The plat will just say "better than 1:10,000". I won't be getting a trophy for that. It could just be that -errors and +errors just cancelled each other out...same applies to level loops. Traverses don't make or break the surveyor. We provide so much more to our clients and the public.

> I have just tried this 3 times on a pratice set and it seems I was geting a little tighter each time. Seem like good advice I do appreciate. How long does it take to be able to get it on ur first or second try everytime

It should not take too long. Just swing the angle, stop a little short on the left side of the target, lock, fine tune to the right until the cross hair reach the target.

> If your looking for tight angles use plumb bob . Google it if your not sure what that is..

😀

> If there is any sloppiness or "slack" in the scales, they can be moved when you turn the instrument. As you turn the gun, the scale moves until the slack is taken up, the scale or sensor are then stopped at the limit of the looseness and begin the measurement. If you turn the gun back the other way, measurement does not occur until the slack is taken up again as it limits out going the other way. To picture this, think of a Master combination lock. You turn the dial one way, then when you go back the other way, it takes a bit for the mechanism to get picked up and turn. When you are dealing with those tiny scales doing the 360/60/60 thing, a little goes a long way. This was SOP with T16s and T2s. Not sure if electronic instruments are susceptible to this, but I've always done it this way with good results.

Ditto. It was the way I was taught at I See O Hall too.

It would also help to use a tripod and tribach in good adjustment. Prism poles weren't really made for traversing, but will work if careful. If you do use one, make sure the bubble is plumb.

Even though it's a new instrument, if you set up in the office, turn sets to some small targets on the walls and still get 30 second bust, it may be that the instrument needs to be collimated,(don't forget to do this) or service. I've seen it happen with a new instrument. I even have my instrument certified once a year. It only cost $25 extra when being serviced. In my work, it's good for me to have that cert in my job file.

Make sure you have minimal parallax. The easiest way that I know to adjust this is to point the scope at the sky and focus the image to infinity. Then adjust the focus of your cross hairs as close as you can. You should be good to go. Everybody's eye sight is different so you should do this anyway if someone else has been using the same instrument.

Has anyone mentioned to collimate the gun?

Maybe it's just me but I don't trust robots to turn sets. They can do it mathematically and never miss.

The last big company I worked at was having issues with busted traverses. On a rain-day they kept me in the office. Me and the survey manager, Chris, decided to setup a test in the office to turn sets/double angles (whatever vernacular you prefer). He challenged me to turn 5 sets with less than 15" error. I laughed at him saying I'll turn them all day long under 10" more likely under 5" and if I couldn't he could fire me right then. (We were already friends from before so that wasn't going to happen but we did bet lunch). I had never turned sets with their guns so I probably shouldn't have been so boastful. Never the less, I killed them all under 5". I ate good that day and had a beer.
A couple weeks later me and my partner, Victor, were unofficially deemed the "busted traverse fixers". They got us/me a brand new gun, data collector and Dutch Hill tripod saying "you own that now Eric". Wow! Talk about Christmas coming early!

We did change our field procedures in that we did use plumb bobs to get angle. On a couple of occasions I could see the nail head through the scope and never called for a shot on the string. I'd just said to put the point in the dimple. I got challenged on that once and said you come run the gun and I'll sight you and you'll see. I never got challenged again. They didn't get the hint that I was wanting some time off the gun however.