Shark Scope...Coke Bottle Binos...Mini Dob...Like I Said, Nonsense

8 inch f/6 Shark Telescope

The tube is made of spiral wrap paper also known as Sonotube or concrete form tubing. I added two internal “ribs” made of 1/8 inch by 3/4 inch aluminum strips which anchor the dorsal fin/handle and the altitude bearings. Attaching the handle and bearings to an internal frame will make it more difficult to adjust the balance than if I used a cradle, so if I ever add more weight to the front end, such as a bigger finder, I may have to compensate by adding a bigger tail fin. Or more of them.

I mixed some sand into the paint used on the outside of the tube to hide some defects in the tube, and to give it a shark skin like texture. Because of this some folks have noted that its not as "cuddly" as the cow scope. Can't please everyone.

I ground and polished the mirror at the Mirror Lab of the St. Petersburg Astronomy Club in 2014. I used a thin (3/4 inch) eight inch diameter plate glass disk and experienced no unexpected problems due to the glass (plate instead of borosilicate) or it's thickness (thin vs full thickness). I did most of the work on the scope in February 2016. Final assemble and first light took place on 3/3/2016 during the OBS Star Party. First light nearly became first bite due to a minor balancing issue, but adding some extra jam nuts on the focuser mounting screws added the needed weight on the front end.

Coke Bottle Binos

A few years ago I saw a video in which

someone cut the bottom out of a plastic two liter soda bottle and fitted a magnifying glass and an eye loupe to make a rudimentary telescope. I though if I used a glass bottle and a real lens and eyepiece it would actually work as a telescope. I ended up cutting the bottoms out of two coke bottles and gluing 52mm by 190mm lenses from Surplus Shed, and inexpensive 17.5mm telescope eyepieces to make a pair of low cost and hopefully comical binoculars.

To attach the eyepieces I glued an empty filter cell to each bottle neck and the eyepieces screw onto the cells using the built in filter threads.

The parallelograms counter weight is covered by a boxing glove. This should prevent damage to the weight if it should accidentally hit someone.

I remounted the eyepieces using 3d printed tubes with .6mm pitch threads glued to the tops of the bottles. The eyepieces screw onto the tubes using the built in filter threads

Eyepiece will screw onto 3d printed tube when glued onto bottle

3d printed lens cover

3 inch f/6 Dobsonian

While many find this scope amusing it actually did not start out as a joke. When I first started grinding the mirror for my 14 inch scope I planed to make it as a Dobsonian with the usual eight truss tubes. I had a 3 inch mirror that I got from Surplus Shed a few years before so I made this scope partly to play around with the design, but also because it was easier to show friends and family a model than to try to explain what I was working on. By the time I finished the 14 inch mirror I decided to go with the three tube design.

Every 3 or 4 years or so I bring it to a star party or other event and have some fun with it.

other scopes

14.25 inch Dobsonian Galileo Scope Isaac Newton Scope Udder Nonsense (cow scope) Other Nonsense (coke bottle binos, shark scope, etc) Crayford Focuser Solar Scope Binocular Mirror Mount Barn Door Tracker Canoe Sailing