Below are a couple of pictures of an old-style Topcon 360 prism.?ÿ Do any of you know what was originally intended to be mounted on top of it??ÿ It looks like a 1/4-20 thread in the center, and two very small threaded holes offset from the center.?ÿ I'm guessing this was for mounting the first or second generation remote controller??ÿ Any clues would be appreciated, as I'm considering how to adapt for use with more common 5/8-11 threads.
I believe that was for some sort of remote target finding laser that the gun would search for because the early robots were so terrible and losing lock etc.
Seco makes an adapter to go between the two. I think it was made to attach 5/8-11 prisms to the 1/4-20 or whatever on the top of fiberglass level rods.
In the picture on the right, I believe the prism is upside down.?ÿ The picture on the left shows the top of the prism.?ÿ I want to mount my RC-PR5 on top of this prism.?ÿ The RC-PR5 has 5/8-11 male thread on the underside.?ÿ Are you saying that SECO makes an adapter for that purpose?
Below are a couple of pictures of an old-style Topcon 360 prism.?ÿ Do any of you know what was originally intended to be mounted on top of it??ÿ It looks like a 1/4-20 thread in the center, and two very small threaded holes offset from the center.?ÿ I'm guessing this was for mounting the first or second generation remote controller??ÿ Any clues would be appreciated, as I'm considering how to adapt for use with more common 5/8-11 threads.
I used to have a GTS-802A robot with this type of prism.
The 1/4" thread in the first picture was for attaching a sheet metal bracket for an RC-2 controller and is intended to be the top of the 360?ø prism. I'm not sure why you would want to mount an additional 5/8-ll device on top of this. The two small holes are for attachment of a pointing indicator similar to what is commonly on top and bottom of Topcon instruments.
The 2nd picture is upside down and has the common 5/8"-11 threads to attach to the TOP of a rangepole. The prism offset for this is 0mm.
@big-al I may have used that plus a short male/male 5/8-11 adapter to put a standard prism on a fiberglass level rod. Something like this is what i was thinking of
I went to the hardware store this morning and found that the center thread is actually metric - M6 x 1.0 pitch. The two small screws are M2 x 0.4 pitch.
The reason I'm doing this is that I'd like to mount my RC-PR5 on top of this style prism. It has a male 5/8-11 thread on the bottom. Although Topcon makes a new style 360 prism for use with the RC-PR5, and it is a very good prism, it is also considerably more prone to being damaged (the individual lenses are held together with some sort of silicone like substance), and VERY expensive. Below is a picture of the new style prism, which sells for close to $1,500. There are Chinese alternatives, that are reasonably priced, but I have been dissatisfied in the past when purchasing such alternatives. The machining/quality control is not on par with the OEM. You get what you pay for.
By comparison, there are quite a few of the old style prisms available on the used market, and I've bought them for around $100 to $150. Another advantage of using the old style 360 prism instead of the new style is that the offset is 0mm. Because of this, I would also be able to set all my 0/30 prisms to the 0 offset side, and thus all my prisms would have the same offset and I wouldn't need to worry as much about that.
I found some metric to inch adapters at McMaster Carr, an excellent source for this sort of project. I couldn't find one piece to do it all, but two pieces together will do the job.
I was thinking along those exact lines. Hayes Instrument Co. stocks that adapter and i believe that I have "forced" it to thread into the top of an A6R prism before. The threads are close but not the same. I believe the threads are all the way through the brass part. So, it is possible that one might adapt that to the use desired, but it would not be the perfect solution.
I ran a 1/4-20 screw with a lock washer through the female 5/8-11 so that it protruded out the bottom and could be threaded into the female 1/4-20 on my level rod.?ÿ I then used a male-male 5/8-11 to attach a standard prism.?ÿ It could easily be drilled or quite possibly just re-threaded to take the metric screw needed for the hole in the prism top.
