I'm looking for a type of tribrach adjuster and I don't even know the correct term for it. It's a jig that mounts on a tripod. From it you hang your tribrach and it allows you to sight a point on the ground and adjust it.
I already have a puck type adjuster - I prefer the other style because it can be used anywhere.
Does anybody know where I can buy one?
I use the total station bubble to level the top of the tribrack to adjust the bulls eye bubble. To adjust the optical plummet I set the tribrack on a stable tripod, draw a line around it on the top plate, tape a piece of paper to the floor or some smooth surface on the ground like a piece of plywood. When set up level by using the bubble, look through the optics and mark a point on the paper using the cross hairs, rotate 120° using the drawn lines for position and repeat twice. Locate and marks the center of the three marks on the paper and adjust the plummet to it and check at 120°. Quick, cheap and results in an adjustment that is adequate for the work that I do. Periodically I will put up a range rod and check it for plumb using a plum bob string from 2 sides
jud
Why not just hang a plumb bob and adjust to where it points?
You will still have to adjust the bubble another way. I use the alidade portion of the instrument in the tribrach.
What do you do if your working here ---> Oregon Vortex?
I don't think the plumb bob works correctly there. 😀
> .....From it you hang your tribrach and it allows you to sight a point on the ground and adjust it.
I can't even picture what you are talking about. You hang your tribrach from it? Or did you mean you hang it from your tribrach. Was this a joke about a plumb bob?
Here's a sketch. Pretty crude but I'm on my way out the door to important meeting at the local tavern. The only place I've seen one is at my former employer's office. It would be pretty simple to fabricate for someone with the skills and tools.
You look through your optical plummet to a point on the ground then turn 180 and see if it stays on the point. It doesn't have to be level in order to work.
I think Wild made a device that you put on the tripod head, a piece of metal shaped like the base of a T2 tribrach. You put the tribrach in it, level, see where it points on the ground, rotate it 120 degrees, level it, it should point to the same spot, etc.
You adjust the bubble first by putting an instrument in the tribrach.
Thanks for your replies. Apparently no one is making these anymore. One of these days I'm going to see about getting one fabricated.
Hold the phone there. Take a look at this. We use it and it's great. I think it is exactly what you need.
This requires 2 tribrachs and they do not need to be in adjustment to do an adjustment on one of them. The top instructions show how it's done. Real neat how it works.
Oops. Just noticed you said in original post you have a puck adapter. Sorry. Well anyway here is the instructions for future generations. 😛
Cheers!