Celestron 8SE Dobstuff 13.1": Swayze refigured Coulter mirror, 6 pt mirror cell (2 pt edge support) and CF focuser board made by me StarBlast 4.5 ST80/PortaMount II Zhumell 20x80/Oberwerk 15x70 on a Seronik-style tripod boom mount Hubble Optics 18 inch F/4 mirror.
-DannyMy warehouseMy Channel
Ron NS11GPS Pronto
16" dob Vixen NA140SS
127mm F9 Surplus Shed/Crawmach kit scope
Best of ATM
Quote: the end-on view at the right above should be an octagon, which is what an 8-pole (4-pair) truss looks like from the end.
Quote:Is there an extra 0 in your primary diameter?allan
Quote:For maximum compactness,
Quote: Quote: the end-on view at the right above should be an octagon, which is what an 8-pole (4-pair) truss looks like from the end. hey Mr. Jacobson,what you see above is obviously a schematic with the trusses coming together at the same point so it would be a square.
Quote:Albert Highe goes into the question from an engineering view, um, rather thoroughly, in his book "Portable Newtonian Telescopes". I found his analysis of the importance of truss connector structural detail and location to be very enlightening, and worth the purchase price alone.
Quote: I'm not sure his treatment of (and enthusiasm for) the use of drum shells and bass rings is as convincing - I have to go through it again and give it more thought.
Quote:Question is do we use 3 or 4 trusses? My brother seems to remember from geometry at school that 3 trusses are stronger than 4. I want to use 4. Any thoughts?
Quote:if you use 8 poles, do NOT have pairs across the scope from one another be parallel. Either the poles should narrow at the top or at the bottom, but the structure will be stiffer and sag less when the scope points low if the pole pairs are not in the same plane.
Quote:Don, are you saying that the end-on view should look like a trapezoid instead of a square?
Quote:When 8 truss tubes are used with pole pairs parallel, the weight of the UTA is basically borne by the top two poles on the side. The bottom poles have little tension and they mostly sag.