10″ Travel Truss Dobsonian “Lysithea” – Part 1
A couple of months ago, after a chat with a ATM wizard named Stathis Kafalis i decided that it was a good time to start constructing my own telescopes. Building something with your own hands of course gives you a great learning curve, saves your pocket and exercises the brain. Also is the best way to start observing Deep Sky .. Having all these in mind I started drawing, throwing away papers and checking on line resources. Some books that helped a lot were Richard Berry’s “Build your own Telescope” and David Kriege’s, Richard Berry’s “The Dobsonian Telescope – A Practical Manual for Building Large Aperture Telescopes”.
Well, a 10 inch Dob is not what we call a “Large aperture telescope” but its pretty decent for DSO and is in a safe range to pack it for travel. Travel means pack it up in your backpack and start walking in the desert. No cars and such… No airport problems.. and of course as little hassle as possible (characteristic that derives from minimalism)
Everything has to be very lightweight, sturdy, compact and surely not at the expense of performance. A combination of wood and aluminum in addition with a couple of commercial parts will keep the whole build light.
In this part i will describe the commercial parts i have used ( Note: I have no commercial relationship with any of the vendors or manufacturers mentioned in this article. I just use their products 🙂 ) The choice of the focuser was pretty easy, and with the addition of the kind comments from cloudynights.com i ended up choosing a 2″ helical type. Why? Its small, light, VERY practical. To be honest i had never used a helical focuser before but since the design would be minimal i had no problem trying new ideas. I fetched the helical from kineoptics.com (Thanks Joe and Della). The package had the HC2 focuser with A kit ( for added stiffness with large eyepieces) and replacements for any kind of screw that the whole system has. The whole idea is very good and with small adjustments you can achieve perfect focusing.
As for the finder I got a Telrad. Its pretty light but needs batteries.. Im thinking of making a DIY Telrad using the system that hand powered flashlight use. Maybe in the future. For now its just perfect though. Its very easy to locate objects and far more easier for star hopping. If you have the batteries its the best solution, but i ll have a simple optical finder with me just in case.. These are the commercial supplies i used.
I also got some extra tools. These iclude an electric jigsaw (Bosch), screws of variable sizes that will be described in the post regarding the main construction, plywood blades (2mm-15mm) for the jigsaw, Jigsaw compass (20cm radius), 2 constrictors to keep the pieces firm and lots of sandpaper. In addition i got four, 40cmx40cm “Multiplex” plywood pieces with 6mm width and two, 40×40 pieces with 9mm width for the rocker box. The trusses and secondary cage materials and photos of the procedures will be described in later postings too. Well, the cost would be higly reduced if i already had the tools but now i have the tools to build as many telescopes i want ! 😀