Tribrachs from China

I have a cheap Chinese tribrach that's right on the money. I think the problem is that you could get one that's not. I think the consistency is not there.

The one I tried was JUNK. I now only use ones made in Hungary, which are the Trimble tribrachs.

Definitely a hit-or-miss purchase with goods from China. I have one tribrach that's halfway decent and another that is not. Prisms might be OK for general-purpose use but in any case, I would prefer the big-name stuff for all my equipment where I need high precision and accuracy. Just my preference.

I bought a couple a while back for $25 each. When I got them I compared them to real Leica's and could not tell the difference. Same color, same weight, same thread count on the leveling screws, same everything. I attribute this purchase to just plain dumb luck.

> ... Same color, same weight, same thread count on the leveling screws, same everything.
Except manufacturing tolerances. This is a precision instrument.

A couple of weeks ago one of our crews came back complaining that their new Focus30 wouldn’t stay backsighted. Losing 30” on the backsight very quickly. Salesman and service department alerted.

Although these guns are just a few months old the tribrachs are much older. Topcon. Before running off to the dealer we had the crew set it up in the parking lot to demonstrate. The effect would not duplicate. I asked if they were using the same tribrach. “No, this is our good one”. “Try it with the one you were using in the field”, says I. Effect duplicates immediately. Tribrach retired, faith in instrument restored. These tribrachs look identical, except for the magic marker number on each one.

I have four and they work very well, they sit on a shelf these days.

They have more plastic and less quality metal parts.

They are not the quality of the Sokkia and Lietz units nor have their durability traits.

With any tool, it lasts as long as the care it is given.

0.02

interesting.....our dealers have been selling mostly what i assume are chinese tribrachs lately. and the only reason i say this is because any of the good quality ones we have have a nice plate or sticker with a serial number. these chinese ones dont have anything and it has me a bit worried. they check just fine on our calibration jig but i have been having the same issue with my focus 30 like mentioned above. very quickly it will loose 10 seconds on the backsite...which doesnt make sense to me because it has a compensator

It probably just needs tightening of the little screws that press down the threads against the leveling screws so they don't wiggle, and a leveling/pointing calibration check.

The Trimble tribach's aren't all that great - flimsy. light weight, poorly coated and crap metal underneath. They break pretty easily too.

While our firm uses all Trimble equipment, we we much prefer those from Leica.

I have had poor experiences with cheaply made gear; the new Sokkia legs and omni tribrachs come to mind as being real junkers.

I thing that the longevity of name brand gear provides value in a way that a mishmash of cheaper knock offs and junkers do not.

That said, everyone is cutting corners now a days and I would look for savings in buying older used tribrachs that are in good condition and having them serviced by a pro, the older Leica tribrachs are better than the new in my opinion.

I wonder if we are talking about the same ones? We have had one break...it was on a lock wall in a sudden storm, and flew 60' across the lock chamber (on a crain tripod), smashed against the opposite lock wall, then fell about 40 feet to the bottom of the dewatered lock chamber (hard bottom). The tripod and prism were OK, but the tribrach did crack.

I won't dispute the quality of the Wild tribrachs, though. I do have a couple. The Trimble ones we use are without optical plummet, although I also have two with plummets that came with our GX scanner, but those are only used for scanning.

In the early days of GPS (mid 80's), we used Macrometer V1000s. These had 40 pound antennas that had a quite large groundplane. The unit itself weighed 160 pounds, and you needed a generator to power it. But I digress...When you put one of these antennas on a tribrach on a tripod, you just hoped it didn't get too windy. Gusts of wind would rock the antenna, and tribrachs wouldn't last long. The Leica's seemed to hold up the best. The Japanese tribrachs would get loose very quickly and had to be replaced often.

> I have a cheap Chinese tribrach that's right on the money. I think the problem is that you could get one that's not. I think the consistency is not there.

From memory, I read an article once which described consistency in manufacturing processes. For example, where the Japanese would test a sample from a batch of 25, the Chinese would sample from a batch of 100. This means that it would be 4 times more likely something would slip between the cracks.

This wasn't a survey related manufacturing process, although it gives an insight into manufacturing industry practices. Manufacturing process' may be the same in China, but quality control isn't as stringent.

I would be inclined to purchase accessories consistent with the instrument manufacturer for piece of mind, or at least accessories that the respective dealer keeps in stock.

The tribraches are relatively good. They seem to require adjustment more often that most. For the money though, and the ease of adjusting, nothing that would keep me from purchasing them.