Erik, I haven't done the math so these numbers could be off a tad. But not much. I'm running short of time so if someone else wants to do it to the inch before I can, go for it. A 40 inch Newtonian with a 5 inch secondary would have to be about an f/8 or slower. That means about a 24-foot-long telescope. The ladder needed to observe objects near the zenith would have to be about 12 feet taller than the ladder needed with the 70-inch folded configuration. Compromises must be made, I think Mike made some good decisions with the mirror. On Tue, Oct 29, 2013 at 2:45 PM, Erik Hansen <erikhansen@thebluezone.net>wrote:
and what about a 40 inch with a 5 inch secondary.
Or how about a 70 inch f4 with a 10 inch secondary.
Please share the math, my telescope building texts are buried away.
The motors will be a good addition.