Saturday, June 16, 2007

Tube Preparation




Well Here are some of the pics I took of the tube surface preparation. I used some heavy duty 15 minute paint remover from Home Depot along with some old rags, paint brushes and alot of patience. The first picture was taken about 20 minutes into the initial removal process. With the fast acting paint remover it literally bubbled in front of my eyes. Using an old rag to pull the old paint really sped up the process without putting nics in the tube surface.
The next picture is about 2 hours later after 3 treatments with the paint remover and lots of washing and sanding with 200 grit paper. The last picture is of the final priming on the tube using 3 coats of Rustoleum grey primer. In between each coat I wet sanded the tube again using 320 grit paper to remove all the little imperfections.
All told it took around 5 hours from initial paint striping to final coat of primer on the tube. Its so nice and smooth I can't wait to pick out some paint and clear coat to finish off the outside of the tube.

Rebuilding an Old Tasco 11TR Reflector Telescope


I recently picked up an old Tasco 11TR 4.5 inch reflector telescope on Ebay for $20.00. When I first saw this on eBay I was surprised that no other amateur astronomy buffs were interested in purchasing this, and to my joy I managed to get it for such a low price.This old beast does not have Goto, or Autostar or any of the fancy electronics on it that today's small amateur scopes come standard with. You have to manually align the scope to the pole, find two bright stars to adjust the axis and God forbid use a star chart to find objects in the sky.
This scope built back in the late 60's by a Japanese company and then sold at Sears and Montgomery Wards or though mail order is a well made if not well accesorised telescope. It is a solid Newtonian reflector with metallic construction and wooden tripod legs that weighs a good 25 pounds fully assembled. The specs are 4.5" main mirror, F=900mm with a 1.22" secondary. The focuser is a .965 and came with a 5mm, 12mm and 15mm eyepieces. Not the ideal focuser or eyepiece set but I hope to rectify that in the near future.
Well in any case this is a real joy to use even if it is without some of the more advanced niceties of the new Meade or Celestron scopes. Even with the obvious flaws in this small scope I was soon to be impressed with the sharp optics of this old telescope.
The first light experience with this scope was impressive. Even in the light polluted skies of western central Florida I could see the Pleadies, Orions M42 and the rings of Saturn. What an amazing scope for casual observing. I had it out of the box setup and aligned in about an hour. Just before sunset I pointed it out to Venus and with the 12mm was able to see the half full silhouette of Venus before it went down behind the nearest tree. It wasn't long before I had it pointed up at Jupiter and could discern the 4 moons and a slight streak across the body of Jupiter. Wow I was seeing one of the bands of Jupiter with a 4.5" telescope that cost me $20 bucks!!
Well after a few weeks of using the scope I started thinking that with a new focuser some extra dampening on the mount and a few new parts including a new paint job this might be even better. I set a budget of around 200 to update the scope. With this price ceiling I am hoping to get a new focuser and some 1.25 eyepieces along with a new set of mirrors, repaint the tube and put some rubber washers and such on the tripod to help dampen the vibrations.

So I have decided to start rebuilding this little 4.5 Tasco in the hopes that I can improve what I have into a solid easy to setup telescope for use around the house or to take out on the road to the dark sky site I often go out to.

So here is where I am at so far: I have removed all the parts from the tube, stripped off the old paint, sanded with 500 grit and primed the tube. I have posted some pictures of the initial messy stages of stripping paint, sanding and the priming. Its a start, the only snag so far is the broken main mirror. I was unable to notice the damage until I removed it from the mirror cell and the pieces began to fall out. Here are a couple of pictures of where I am at right now.