Curious as to everyone's thoughts on aluminum tripods. For years I have been told that they should never be used due to expansion properties of aluminum. While I do believe in science, and I have faith that aluminum will expand at the temperature increases, I don't understand why so many really think that this would cause large errors in normal uses. In my case, I want to by one for deep woods traverses and level runs. When running levels, the level itself is only on the tripod for 5-10 mins per turn and when traversing through the woods the gun won't be set up at the same station for hours, or the all day - so what's the harm in using a aluminum tripod?
I have no problem with using a sturdy aluminum tripod for leveling. I don't think I'd use one for a total station, obviously not for a robot or GPS. When I was in sales for Leica in the '90's I had four GPS systems shipped in for a rental, the client told me not to ship tripods (GST20 and/or GST20-09) because he had them. I showed up on the job site on a sunny South Louisiana summer morning and his tripods were all aluminum. Not one single baseline from that entire days sessions processed successfully; needless to say that evening I had the tripods shipped in. That was pretty much the last time I used an aluminum tripod for anything other than an RTK radio antenna mast.
I agree I don't think I would use it for any set ups that would last longer than 30 mins. My main use would be level runs where you turn and burn. Only TS work would be my old lock down Topcon/Nikon where I am just turning through some traverse legs or tying down that one pipe deep in the holler.?ÿ There is nothing worse than running a 2 mile level loop with a TriMax Tripod, at the end of the day your shoulder feels like you've been shoot skeet.
I think a quick turn with a Topcon or Nikon TS would be fine as long as you double check your centering, leveling, and height immediately prior to making the observation. It would have to be a sturdy one though; Lietz/Sokkia used to make a good one back in the '90s.
At 13 ppm/degree F for aluminum, and assuming a 45 degree rise while warming in the sun, a 5 ft leg would grow 0.003 ft. If that's the accuracy you are holding, dont use aluminum in intense sun.?ÿ
But for most work I would think it is okay.
What about humidity and wood tripods on long sessions?
Can you get the legs planted with any more stability than that in the soil you are on?
I've never seen an aluminum tripod that was robust enough to properly support a modern total station instrument.?ÿ Aluminum is OK for levels because they are lighter and because the setups are typically of short duration.?ÿ ?ÿ?ÿ
If you are looking for lighter tripods for woods use I'd look to the Leica GTS20-9 or similar. Not exactly light, but very stable and lighter than Trimax.?ÿ
Humidity with Leica tripods was never an issue because of the quality of the paint.
Aluminum tripods are great for a TS run thru the forests and a matched set can leapfrog quite well.
I use heavy duty dual locking aluminum legs, Sokkia (1) and Stabila (3), for thru the woods and have the solid fiberglass SiteTech for most every other application.
Aluminum does appear to require more maintenance and checking and basically, like all tripods, every nut and bolt has to be checked for tightness before and during the day if any wiggle is found.?ÿ
An IMan tool kit with allen wrench - box wrench combo and screwdrivers that fit all the different sizes needed is a must. I keep everything needed in a zippered bag attached to my instrument backpack.
I have observed aluminum transfers vibration much more than wood. On a breezy day it can get unworkable real quick.?ÿ
I have only one aluminum tripod, the SECO mini-tripod. It has been useful on those rare occasions when you need a shorty. And it will very likely be the ONLY aluminum tripod I own 🙂
How about carbon fiber?
The Dutch Hill black composites have done a good job for me.?ÿ Light weight and have held up real well.?ÿ The angles while using our Trimble 5600 always close well.
The one thing I would mention IS while working with another surveyor, he could not get his angles to close loke they do with his Lieca wood tripods.
angular stability is the problem. grab the head of the tripod and give it a twist. aluminium ones are much more flexible.
small angular deflection, can equal big error at distance.
no problem for levels and gps. as long as its not long duration in strong sunlight.
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Beyond the temperature thing, most aluminum tripods that I have encountered are just poorly constructed. I ran into a set of Leitz aluminum legs that were pretty solid but they have been the exception.
For an optical level I see no issue, if running a digital level it seems to me that it would cheapen things up a little to not use wood legs.
In my experience running traverses through wooded environs is that you run into poor conditions for set ups and need to stomp legs deep into the earth which puts a lot of stress on the operation, so having solid legs is important.?ÿ
That said, it is not like buying a new truck or something, if they do not work well for one thing at some point a aluminum tripod may come in handy for something else.
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Good point - I have not thought about vibrations...
Dutch Hill composites get it done.
only used aluminum on grading at construction sites. Slam bam thank you?ÿ set ups.
No one has , as yet, mentioned Leica's White Paper on tripod stability. In it they compare angular results using various types of brand new Leica tripods. We are shown that it makes a big difference what tripod you use. One can only suppose what happens when you mount your shiny total station on some floppy old legs.?ÿ?ÿ
There is a similar white paper on tribrachs.?ÿWhich seem to have a still greater effect.
No mention in there of the cumulative effect of mounting your TS on floppy old legs and chinese tribrach. But experience tells me that angular precision in the +/-30" range, or worse, can be expected out of your 3" gun.?ÿ
