Seco Geodesy tribrachs and prism holder with optical plummets

If your current adapters do not have spirit levels on them you should definitely improve your results with new ones with 30" vials attached. Never been a big fan of OP's mounted on the tribrach. They are a little harder to look through being so close to the tripod head, and more importantly, you can't easily check them for plumb. When my newer instruments shifted over to laser plummets it is even easier to check, like every setup.

All of our work is done with tribrachs without optical plummets. Our instruments have built in OP's that rotate with the instrument, and we have the separate rotatable OP's as well. While it is probably the same accuracy as a well adjusted tribrach with built in optical plummet, I don't have to worry about the plummet on the tribrach being knocked out of adjustment, and I can always check the adjustment by rotating. By rotating it I believe we can center to ?ñ1 mm even if it is slightly out of adjustment. We carry the rotatable OP's in padded prism cases.?ÿ

As John describes, there are definite advantages to having a rotating OP.

If that is in the instrument, there is the problem that you have to be very careful about any tripod leg adjustments to get over the mark so you don't jar the instrument or let it fall.?ÿ I know of an archaeology professor who uses total stations to record every item in a site, and he won't let his students adjust the legs with the instrument in place.?ÿ They sometimes spend 5 minutes adjusing the tripod legs, putting the instrument on, finding it isn't close enough, taking the instrument off, adjusting the legs, etc.

Thanks everyone, that's kind of what I was hoping to hear. I figured that being able to level up using a vial level (and being able to turn it 90 degrees) had to be better in itself. I like the idea of being able to check the OP so easily too.?ÿ

I also go the answer I was looking for on the Seco tribrachs too. The High Precision one is the one I want as it is spec'ed the same as my original Focus 35 tribrach. I'm betting that they're the same exact tribrachs being that they look the same and are both Trimble owned.

Gregg

The tribrachs I use are Trimble and are made in Hungary. Beware cheap knockoffs.?ÿ

I have been using Seco tribrachs with optical plumb with great success for 35?ñyrs.

Use the Seco 2002-00 bubble adjuster regular to keep them in check

Currently, I have 5 Seco tribrach for sale complete with donut and optical plummet

Have 6 Sokkia/Leitz in my truck that I use daily.

The other two in this picture are for spare parts

message me or send email to?ÿ ?ÿ h a r r i s s u r v?ÿ a t?ÿ ?ÿy a h o o (with no spaces .com)

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Have experimented with cheap/expensive options of tribachs with OP/ tribach with adapter.?ÿ

1. You cant use the adaptor with OP on a tribach with OP.?ÿ

2. Do not cheap out on using cheap tribachs or adaptors. The dollars you save initially adds up in the time spent adjusting it weekly or when it has taken a knock. My expensive options hold their adjustments really well and when it was accidentally dropped, the adjustment ran a little. For the cheaper option, I found that that the centering always ran no matter how much thread lock I applied and had to check the centering weekly.?ÿ

3. My preference is to have the adapter with OP as I can easily check the centering and also the accuracy of the bubble easily.?ÿ

4. Yes, my traverse results from using a adapter with OP is much better compared to tribach OP. The more sensitive bubble on it plays a part in it.?ÿ

The Seco Geodesy series seem to be a step up from the standard $140 seco tribrach, at least in price. That being said, I found Leica GDF321's without OP's for $260 each and I'm thing of going that route instead.?ÿ Any thoughts on those tribrachs?

Gregg

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I found Leica GDF321's for $260 each so I went that route on the tribrachs. They were $20 cheaper each than the Seco's.

Gregg

@a-harris

Thanks for the offer but I went another route.

Gregg