Anybody ever buy one of these???
Posted 19 January 2004 - 01:01 PM
It makes the 17.5 seem positively tiny. I'd LOVE to see a review of that beast. Thank goodness for the truss design.
Posted 19 January 2004 - 01:33 PM
I heard that the 29" did very poorly, the mirror 'potato-chipped'. Basically that means that it was so thin that it tried to 'fold over' and it just threw off the figure terribly. They only sold a couple of those monsters, thankfully.
Posted 09 February 2004 - 08:05 PM
I had a full thickness 14.25" dia. Newtonian on a Cave Mount and optically it did a very good job even on planets.
I had a friend who bought a Dobsonian 10.1" it too performed well.
It is likely that inadequate mirror support on the thin and larger mirrors caused them to warp and introduce astigmatism.
That is why the larger the thin mirror Dobsonian the point mirror support points they need.
Posted 10 February 2004 - 06:55 AM
What could this mirror do if it was mounted in a truss-tube design and allowed to ventilate? I think that is the main drawback of the original tube design, only one opening for air to get in and out. I don't see why potato-chipping should be an issue unless you're looking down near the horizon. I just got a copy of Krieg and Berry's book, and I am going to give the 13.1 a home it deserves, a truss tube 18 point flotation system. Great book, by the way! The coulter optics mirrors are thin, but if they are supported correctly, and well collimated, there is no reason they should not perform as well as a full thickness mirror. As a matter of fact, they should stabilize thermally quicker than a 2 inch thick mirror.
Posted 10 February 2004 - 10:52 AM
Posted 10 February 2004 - 05:29 PM
Consider that quote saved for posssible further use
Posted 10 February 2004 - 05:54 PM
Last time I saw something like that they were firing a clown out of it and into a net!