Darwin B recently built, in nearly record time, an interesting, two-truss, tubeless, collapsible, travel-ready Newtonian scope at our DC-area telescope making workshop, using an 8″ parabolic mirror with a short focal length that he bought.
He mounted it on a commercial alt-az tripod, as you see here. It will definitely collapse and fit either in a suitcase or fit in carry-on spaces on an airplane.
Unfortunately, there are some drawbacks, as he is the first to admit:
- The lack of any sort of light shielding is a huge problem virtually anywhere within a hundred miles of a city;
- The ultra-cantilevered mount makes it very wiggly; images essentially never stabilize. It’s also extremely susceptible to breezes.
To quote from a recent email from him:
So let me first plead mea culpa!
1. Anywhere near DC-MD-VA, open structure telescopes are TRULY instruments of the devil! (How do I come to fully agree with you on this point? Well Tuesday morning before dawn, in the cold, I set up near work – well that 70mm mirror does an incredible job collecting light from a wide area! That also explains my difficulty at CC the other night.)
2. I am asking for “un-attainium” with my scope: big aperture, fit as 2nd item carry-on, have a good mount, and be useful locally.
3. Perhaps many people would be better off traveling with binoculars- smaller & less hassle than a scope. And would do a great (limited) job anywhere.
So what to do?
1. Fix what I can on this scope and accept limitations- fix spider, swap sides for saddle, and add a shroud. Limit to low & medium power and enjoy.
2. Since I have an 8” f/6 mirror, build a scope for around here & car travel: and not have the limitations of the other scope. I already have many/most of the parts for a design similar to your 6” f/8. Like you say, it’ll be steady, and I can crank up the power a bit for moon&planets. It just has to have the mount break down flat like an IKEA.
So, I’ll be up at the shop next Tuesday nightto drill holes to flip saddle. I should have other things done or started.
So – now you have a pretty ringing endorsement for your thoughts.
I can compare my current effort to a beach house or a boat; wouldn’t want to live there year-round. BUT they can be fun, within limits.