Just curious why Trimble sends all their 360 prisms out (mt1000s and yellow 2mm 360 prism) with the bubble on top nowhere close to plumb? And do you guys adjust them yourselves? They don't seem to come with the correct size torx to adjust it ourselves.
I'm curious as to why they put level bubbles on them at all.
@brendan8762 actually kind of useful - screw a point straight into the base and use for setout on busy sites
No way to adjust it that I know of, but @jimcox is right on - the only time we use it is for a very low rod height, around 0.15m or 0.5ft. At that height fine-tuning doesn't affect centering enough to worry about it, especially considering that the 360s aren't intended to be HP units in the first place.
In theory I get that but I only ever use 360 prisms for rough work (aka pole work), if I'm getting that close the to the ground then I'm likely using a mini nodal prism.
So I guess the theory is they suck bad enough to not bother with the bubble (even though I get within 5mm at worst on distances I tape between what I set with it).
I still think for the price of these things Trimble could have bothered. But there is lots of other things they didn't bother with so I shouldn't be surprised.
Why does it cost so much: because it can, and even though it is all made in china and looks the same, we dont feel we can risk the cheapo stuff.
If they were as bad as many seem to think they are (I don't think they are based on my checks over the past couple years) then we might as well use no name stuff. Why pay $5500 for a prism that is only good for "rough work".....I use the active prism because of the how bad the s series is at locking onto our work vests in passive mode.
I've started only recently using a mini prism when I'm pinning walls on footings because at least then it's obvious when it's locked onto your best because the point won't land in the correct part of the footing.
All this negativity about the active track prism! It works great for 99% of survey work. It is unparalleled for tracking ability in most uses. BTW, I worked for many years with a Trimble 5603, which had no passive tracking option at all.
I've also used Leica and Topcon in recent times. I like the Leica, hate the Topcon. I could happily work with Trimble. IMO, the tiebreaker with Leica is the accessories and the carrying cases. Leica the clear winner there.
I actively despise all active prims I have ever used, no matter what they call them...(Topcon & Trimble, haven't tried Leica's but it is unlikely I would like it, unless the auto rod height actually works...might save some blunders there).
I honestly haven't had issues with the accuracy, but I'm mindful of the vertical angle and whether I'm using semi active or active for the accuracy I need. I just wish for the price they cost that it would have the accuracy needed for that last 1% of jobs and a properly adjusted bubble so I could use it on a mini pole or just a threaded point that screws into the bottom. Maybe a battery indicator would be nice too.
I didn't like the sokkia I used to use either, it's active setup was extremely clunky and tedious for jumping in and out of the truck.
The Leica 1203+ robot doesn't need an active prism in my usage as it doesn't lock onto reflective vests and the Leica grz4 360 prism has a quick release which is handy for jumping in and out of the truck. It's also around 1/5th the price of the mt1000.
I do not consider Topcon's RC-5 or Leica's AP-20 to be "active prisms". In both cases the prism is still being tracked passively. I haven't had a chance to use, or even test, the AP-20 yet. I find the powersearch on the Leica TS-16 to be very effective. Also, I have used the tilt correction on the Leica GS-18 receiver -its a game changer. So I'm looking forward to adding an AP-20 to the tool kit.
<div>❤LEICA!</div>
https://g2survey.com/blog/leica-ap20-autopole-how-it-works-the-benefits/
Yeah powersearch was under rated. I didn't realize how important it was until I switched to Trimble. I can use the Leica robot with Trimble access unfortunately the one thing that doesn't work at all running it that way is powersearch. It is a little better at finding me with GPS search than the Trimble s5 though as it doesn't seem to require as perfect vertical pointing to see the prism.
I'm loving my AP20. For topo I'm amazed how many things I've been able to get without another setup just because I can lean the rod out a bit. It has been hard to get used to not stopping to leveling up for every topo shot. It really shines in layout, the amount of time spent getting a rough location is cut by way more than the 20% number Leica was throwing around. I had a layout job in a tight rail corridor where I marked track offsets on the vertical face of a wall on one side, and under a bank of conduits on the other side. While I could have done the wall from behind the instrument with a well-seasoned tech, I don't think the conduit side would have been achievable without an out of level rod.
As for the hardware itself, a Leica commissioned white paper points out that, on a 1.6m rod within 5 degrees of vertical, the tilt sensor is more accurate than a handheld bubble. The auto-height measures in 5cm increments at pre-determined locks on the pole. If you are not snapped into one, the HR is blank on the CS. The prism ID is not an active tracking system, it just will not let the TS shoot any prim that is not on the AP20. I'm not quite sure of the mechanism, but it seems to work even in brush when the AP20 itself is obstructed from view.
They still have a couple of firmware issues to work out, but those are related to workflow which I'm sure will be worked out soon. I also think they have the IMU tied to tightly to the TPS results. In some situation where you are moving slowly, the IMU loses initialization instantly if you lose lock even for a second.
I'd love to have the ap but unfortunately it will never happen as my boss switched to all Trimble gear only because we were merging with another company that is all Trimble (apparently another company they bought had to switch from Leica to Trimble 🙁 <div>
The IMU on the r12i is very handy for certain things but unless I know I'm going to use it (like for a rough staking for excavation or shooting something under a fence or something) I will turn it off, because if you have to change your rod height it loses your lock and has to reinitialize the IMU again, or if you lose your lock in the trees it will struggle to reinitialize. I find it I need accuracy, the longer it has stayed fixed, the more accurate the results, so I prefer not to lose fix unless I need to confirm it's a good lock or I am doing rough work.
I imagine Trimble will be a long time before they have something similar...since they don't even have powersearch or anything similar (GPS search doesn't count unless you're using integrated surveying).
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