Posts Made By: Nathan Spitzer

So I am making a GEM for a small refractor and hopefully a little bigger reflector down the road. Each axis rides on 2 pillow-block mounted bearings with 8 inch long 5/8 inch axles. This is all mounted on 6" aluminum channel with a pedistal of 2" iron pipe and is adjustable between about 36 and 42 degrees lat. Since I live at 39 degrees lat this covers me over almost any place I would want to go. I left enough overhang off of the back of each axis to put setting circles but have so far failed to find a place where I could obtain some that I could modify to mount.


Does anyone know where I could get a set of setting cirles that would work in this application? I don't expect to be able to point blind, but I would like to at least get close enough that a wide-angle spotting scope could help me zero in on my target. While I could rig up digital setting circles if I can't find old-fashioned ones I was hoping to avoid the additional expense.

Any help you could provide would be appreciated.

Nathan Spitzer

PS: This is almost identical to one shown in "All About telescopes" though I had designed it based (lossely) on some internet designs and ordered the parts before I got my copy of "All about Telescopes".

So I am trying to make a pipe GEM almost exactly like the one described in "All About Telescopes" and here: http://home.fuse.net/astronomy/gem.html . I live at 39.2 degrees North (Charles Town, WV). Now both the indicated site and "All About Telescopes" say to use a 45 degree elbow and call it a day.

My question is simple:First, am I missing something about the design, and second for a beginner interested in looking at the moon, planets, open clusters, and easier nebulas and NO interest in astrophotography, how much practical difference will it make if I use a 45 degree elbow versus doing the extra work to support it at 39 degrees?

Its VERY interesting that you show this because I am building a pipe-GEM mount from "All About Telescopes" and I keep seeing this design and wondering if it would be worthwhile.

Let me know how it works out!