The other day some one here posted an inquiry about checking the verticality of an elevator shaft. This reminded me that a while back I had bought a Zenith plumb, but was unable to use it for lack of a base. Here's a pic:
It is made by an English maker - Cooke, Troughton & Simms. As you can see it has some sort of strange mounting (not a standard tribrach) that I have not ever actually seen one of and wouldn't know where to get one. So how do I mount it on this standard tribrach?
Well, a little bit of thinking, some 1/2 inch aluminum plate, some salvage instrument feet, and some work with the lathe & drill leads to this:
When assembled I now have a fully functional Zenith plumb (that also looks down) so that I can now set up over a point and plumb up to points overhead. The nice thing about this instrument, besides good optics & quality, is that it rotates on a central shaft so that if you rotate 180° you can immediately know if you are plumb because any movement of the cross hairs is immediately visible. Here's a pic of the final contraption:
or a 32 oz. plumb bob
Nice work, as usual!
Very nicely done. I remain jealous of your lathe, and am consoled only by the fact that I don't have time to play with one these days anyway.
Dave,
Great job, you could patent that.
Perhaps we should test it in a real world situation:
or here:
Worst problem is water dripping, always have paper towels handy!!
You will have to make another adapter for the old tripod.
Pictures here for the monthly contest
I'd be glad to loan it to you, but getting me down a mine that looks like that - not likely.
Thanks to all for the compliments.
That is a mighty dangerous looking mine. All those timbers being continually saturated with moisture.
Did your rodman have to climb up that stope?
This is nifty.
Glad you are putting that lathe to some good use.
:beer:
I've seen some sort of mark on the top of instruments before but I've never used it in that way.
We would put paintstick with a cross down for control points on the floor of the conveyor tunnels we ran thru at the paper mills on new concrete.
Those ceiling hangers are the way to go if you ever plan to return to a tunnel.
Have not been in anything like there before and probably not going to be tempted to be.
:good:
Floor marking don't work in an active mine, as they will be long gone in a matter of hours.
The "ceiling hangers" are called spads, and are hardened little squared off fishhook looking things. All your control is in the ceiling which works great unless you forget to mark it.
I still have a box of spads somewhere.......