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slider prisms
Posted by Dan Patterson on July 20, 2016 at 7:37 pmHas anyone on here ever used those little prisms that slide up and down the pin pole? I just got done a job where I had to climb all kinds of formwork and put wall line and column line marks everywhere. I work as a 1-man crew, so it was all done robotically.
It was a real pain doing it with the rod. I used a mini rod that’s about 0.4′ tall, but that was too short in places where the formwork covered line of site. I see they make 360å¡ sliders as well for robotic surveying. (I guess they’re at either 0mm or some positive offset, so I’d have to be careful to change that).
stephen-ward replied 7 years, 9 months ago 6 Members · 8 Replies- 8 Replies
Dan Patterson, post: 381812, member: 1179 wrote: Has anyone on here ever used those little prisms that slide up and down the pin pole? I just got done a job where I had to climb all kinds of formwork and put wall line and column line marks everywhere. I work as a 1-man crew, so it was all done robotically.
It was a real pain doing it with the rod. I used a mini rod that’s about 0.4′ tall, but that was too short in places where the formwork covered line of site. I see they make 360å¡ sliders as well for robotic surveying. (I guess they’re at either 0mm or some positive offset, so I’d have to be careful to change that).
Yes I use to use them all the time. Sighting in between rebar was a particular requirement.
Never seen a 360 slider. Or maybe I have but the type with many separate prisms topcon or trimble style.I have a mini pole with three sections that has the sliding prism.
It is very good when a slim, skinny, 3/8″ width pole is needed for close stakeout.
Do not use it very much because it can only be used at 0mm prism offset.
All my other targets are setup -30mm prism offset.
Mostly use the pole only for stakeout in prismless mode.
:gammon:A Harris, post: 381835, member: 81 wrote:
Mostly use the pole only for stakeout in prismless mode.
:gammon:I don’t think I have ever used the pole to measure the distance in prismless mode. Do you account for half the thickness of the rod? Is it negligible?
I take many shots in the SDA mode and then give a go or come amount to be in the center of the object, be it post, xtie, prism pole, rebar, power pole, etc. The method also allows for a right or left offset amount.
Wrap with prismatic reflective tape will increase the measuring range considerably and any setting will work, prism, target or prismless. That allows you to make a constant setting in your gun.
The sliding pole I have is 0.03ft thick and has three 2ft sections with a ring on top.
Taller and thicker and easier to shoot than a chaining pin.
Wish I had extra points for the other two sections. It is possible to adapt a plumb bob point up a size or two (gonna work on that fix).
The point are similar to that of a target arrow and would be better suited in being a plumb bob point.
I take my shot and when the DC says go 0.015 I know it is spot on.
:gammon:
I use Sokkia Robots and they have a sliding prism pole which I use for setting out. Looks like the link below. Very useful to shoot between rebars and things that block.
sireath, post: 381863, member: 9370 wrote: I use Sokkia Robots and they have a sliding prism pole which I use for setting out. Looks like the link below. Very useful to shoot between rebars and things that block.
Looks pretty cool, but that says -7mm offset. I don’t understand how it can have a negative offset and be a slider. Wouldn’t the node be inside/behind the pin pole if that were the case? Am I misinterpreting what the offset represents?
Dan Patterson, post: 381870, member: 1179 wrote: Looks pretty cool, but that says -7mm offset. I don’t understand how it can have a negative offset and be a slider. Wouldn’t the node be inside/behind the pin pole if that were the case? Am I misinterpreting what the offset represents?
It’s all about the optical center not the physical center of the prism.
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