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Rotating prism  

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John Hamilton
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For deformation work I like to use -30 mm offset prisms, and i have a bunch of them. I also have two 0 mm offset 360° prisms and one Trimble +2 mm 360°, but I don't like to use these for anything precise due to aiming issues. But, we do a lot of setups, and you always have to go back and turn the prism to face the gun at the new setup.

A neat product would be a remote controlled motor that could be used to change the direction that a prism is pointing. maybe a little light on top to aid in pointing it back to the gun.

Anything like that exist? Wouldn't be terribly hard to make...a small motor and a remote controller with a radio link. Be even better if it was integrated into the data collector.

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Charles L. Dowdell
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In the late 70's, a guy that had worked for me, designed, built and used the remote prism concept. He spent a lot of time trying to get them patented, but the end result of this was apparently it conflicted with some other patent pending item. It may have been the developing of the remote EDM operating system or that they took his idea and instead of revolving prisms, changed the concept to the instrument instead. Needless to say, his idea never really got off the ground as far as being a commercially viable enterprise. He had written a program for his TI59 to do all his reductions to go along with using his setup in the field.

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A Harris
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For those jobs that the traverse will be closed the same day I begin, my first backsite will be one fixed prism assembly on bottom and stack another target and prism on top with each facing different hubs.

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squowse
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Leica mini 360 has very little pointing error and is probably cheaper than a motor arrangement?

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John Hamilton
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Do you have a part number for the Leica version (GRZ101?)? What I have is a large Zeiss 360 and a large Seco 360. I can definitely see the effects of misalignment (my EDM is 1 mm ± 1 ppm).

Lasse Kivioja did research at Purdue on the effects of misalignment of the prism on the distances, and created a very interesting report

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