I've been doing tieouts in preparation for replacing a bunch of land net monuments with standard county well monuments, and found that I got much tighter results using a miniprism down on the ground that on a regular pole. The only problem was holding the prism still. I spent a couple of days trying out an assortment of bracing methods, and finally decided to cobble together a mini tripod for the purpose out of a scrap of 1/2" plexiglass and some carriage bolts. Being able to rest my hand on the tripod makes it pretty easy to steady the prism.
The miniprism isn't much use in the weeds, but all of the project monuments are in roads, so I'm a happy camper.
Jim,
I really enjoy your posts. This is a great idea. It gets you tighter results, AND keeps your hands off the hot pavement. I would have loved to have something like that when I was working on the multi-story hospital. We used a mini-prism to lay out baselines on all of the floors for interior layout. 13 or 14 stories worth.
If you haven't patented this yet, I might borrow that idea if you don't mind. We as a group are a pretty imaginative bunch of people. necessity is the mother of invention.
Thank you for sharing
> If you haven't patented this yet, I might borrow that idea if you don't mind.
Let's just call it an "open source" tripod.
I think I would try to incorporate the mini prism into the lower portion of a short rod , say the bottom portion of a three foot rod, so that I could stand to level the rod on the point.
i was looking into this:
[flash width=560 height=315] http://www.youtube.com/v/S-CBJfkeR6Q?hl=en_US&version=3 [/flash]
I used a small camera tripod before I got the 1' foot SECO bipod, the short stakeout prism and a 1' stakeout pole.
Paul in PA
I like Jims idea and Ralphs neat setup.
I'm a little lazy though, so I bought one of these.
Holds the lieca prism and levels up pretty quick.
Pretty hefty construction as well.
when i was a kid, we always had a block with a target. it was before we shot backsights and seemed to work well. i've always thought about returning (pun intended) to a similar concept.
Here is my solution ...
for holding a mini prism pole. Scraps of wood, glue & screws.
I have been considering getting a "Marksman". We have some deformation surveys where we need to center a prism very precisely about 4 feet above the mark. I would like to use a rod type setup so we can maintain a consistant height of prism. My concern with the "Marksman" that it might be wobbly at that height. We only have a 2 mm error budget. If we go to a system like that, we would use a Leica TCRP 1201+ R1000 and a Leica TCRP 1202+ R400 to take the shots, then load it into an network adjustment package and see what we have.
Wouldn't it be simpler to use a non-tilting miniprism with a point on the top, and invert the rod. I used that system for years and it does indeed increase accuracy.
I believe these are what the oompa loompas used to lay out the chocolate factory 😉
I use one of these, mainly for indoor/industrial setting out. Originally designed for mounting instruments and targets/reflectors on concrete pillars it work fine on hard surfaces. The bubble on the rod passes down throught the centre of the 5/8 thread to the ground mark.
> I like Jims idea and Ralphs neat setup.
> I'm a little lazy though, so I bought one of these.
>
> Holds the lieca prism and levels up pretty quick.
> Pretty hefty construction as well.
>
>
Scott,
Where did you get that?
Ralph
A Leica mini prism with just the point on the bottom and 2 or 3 sticks screwed onto the top is very easy to hold steady and also saves a lot of bending over.
> A Leica mini prism with just the point on the bottom and 2 or 3 sticks screwed onto the top is very easy to hold steady and also saves a lot of bending over.
With my aging eyes I wouldn't be able to see the bubble clearly enough if I was standing up and the prism was on the ground! For the work I'm doing I have to be on my knees anyway to mark line and drive nails, so the mini-tripod doesn't impose any hardship in that regard.
> when i was a kid, we always had a block with a target. it was before we shot backsights and seemed to work well. i've always thought about returning (pun intended) to a similar concept.
Using a prismless total station this still works. Also works well for stakeout. Have carried a target card for plumb bob in my pocked for years, as well as Gammon real. Used both for these purposes and checked with prism later. Always had good results.