My "tubeless" dobsonian has homemade circles for azimuth and altitude. I got a very inexpensive Meade 60mm refractor that has a computer in its mount, the...
Hi Dan, Thanks for your reply. I ended up ordering a Obsession 18UC with Galaxy mirror. Richard ... collimation on the StarMasters is very easy, and is very...
Forgot one step--After I point the "phantom" 60mm scope to Polaris, I turn the computer's altitude encoder by -33* (the negative of my latitude) so that it...
The problem I've encountered with the whiffletree system is how to contruct it so that it is indeed centered on the mirror's COG. They are not a very...
Hi Haryong, I had a similar problem when redesigning the sling on my 24". I came up with a self centering cable system that has worked flawlessly for several...
a URL to the sling album is: http://groups.yahoo.com/group/bigdob/photos/album/835068929/pic/list;jsessionid=C4A0316C44CD38883F3F677A23BE93F9. - Pete...
Hi Tim, I hate to disagree with anyone, but mirror quality counts alot. Having star tested hundreds of scopes over the years, an experienced eye can tell the...
Hi Pete, ... Interesting pictures, but theoretically your cable sling implementation - supporting the mirror only on a part of the lower circumference - is not...
Pete, Robert, I would second Robert's advice to support 180 deg of the edge. Also, I would suggest nylon spacers like you use only at 45 deg each side of the...
I second Richards comments about true mirror quality. You see a lot of claims that "Our mirrors are 1/10PV" or "This mirror is 99 Strehl" and some mirror...
It urprises me that many even today think in terms of P-V errors. At one time when the Foucault test results were hand-calculated by the rather tedious and...
... I have developed a version of the sling that eliminates most, if not all potential sling problems, and it is in production now as a retro- fit for...
I am forwarding this because Ron was one of the designers for the Big Dob movement. Gordon Ronald L. Ravneberg RAVNEBERG Ronald L. Ravneberg, 60, died at home...
Hi Gregg; Very clever. I bought an NGC-60 for much the same reason. Actually, I was going to transplant the encoders into what then was my 10 inch, homemade...
Howie, Will you have one at WSP? Pat M. ... I have developed a version of the sling that eliminates most, if not all potential sling problems, and it is in...
I posted this on CN, but got a response back from someone with a much smaller (12") Dob... I would like to know if anyone is using 3/8-16 inch collimation...
Hello Rich, Go to McMaster-Carr, www.mcmaster.com <http://www.mcmaster.com/> and look up part number 92240A362. It is a standard hex head, 3" stainless steel...
... If the shafts come back from the people who are grinding the threads for me on them in time, I will have them at WSP (With much difficulty, I cut the...
Picky, picky, picky. :-) The issue at hand is to add material to the hex head without adding much thickness to the head. You want to keep the head thickness...
Another option for attached a "knob" to threaded rod is using "Threadloc", blue works, red is better. This is the simplest and easiest method. I use it on my...
Thanks Howie. It's time to replace my old sling and this may be the way to go. Any idea on the price yet? Pat M. ... If the shafts come back from the people...
McMaster-Carr has everything: <http://www.mcmaster.com/#bolts/> (give the link a minute to load- it will show their front page first, then switch to bolts...
I found a knob with a 3/8"-24 threaded hole on McMaster. Item number is 60205K48. Is the knob itself too thick? if not, can I use a locking nut positioned...
I'm not sure why Charlie was worried about the thickness, other than that you might want to be able to set the cell down on a flat surface without hitting the...
Hi John, here are my reasons. * The amount of space between the underside of a mirror box and the floor of the rocker box varies from scope to scope...
Hi Howie Sherri and I dont beleave tieing Pok Sun to the roof would be one of your "Better Ideals." But if you decide to try this we would be intrested in...
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