Killer Scope Mods #1: Primary Mirror Cooling Fan
Step 1) So I went to CompUSA and picked up a 5" computer fan that runs on 12 volts. I snipped the ends of the cable off, snipped off the ground wire entirely, and attached and alligator clip to the end of each wire.
Step2) I pulled out a 9.6v rechargable NiCd battery from my H2 Hummer RC I got from Walmart. Put a small strip of self-adhesive velcro on it and mounted it to the base of the fan. At my initial test, the battery runs the fan for 4.5 hours no problem. It will probably last all night.
Step 3) I used the elastic from an old busted set of workshop goggles (2 bucks at Home Depot), cut the elastic into 2 inch strips and tied each strip to each corner of the fan, then wrapped the loop around the collimation screws. This absorbs any vibration from the fan.
Total cost: $8.00
It would have been more if I would have had to purchase the battery, velcro, alligator clips, and elastic. But I had that stuff laying around.
Killer Scope Mods #2: Mount the NexStar 102mm Refractor as a Finder
So I have this 102mm refractor that really only comes out to look at the sun and at star parties. I want to use it more, but it's a bit of a pain to set up, so ideally it would work best if I just mount it on my 12" Dob.
In order to accomplish this, I needed three things: 100mm rings, a counterweight, black mounting bolts.
The rings and bolts were a no-brainer. Go to Sean's Astronomy Shop
and get the rings. Go to Vancouver Bolt and get black bolts, nuts and washers.
The counter-weight was going to be the trickiest. Without going into elaborate detail about my trial and error, suffice it to say that I ended up with a "Fanny Pack" full of BBs strapped to the scope. This works perfectly and I didn't have to drill any holes or mount a slide-bar on my scope.
Photo: 102mm Finder mounted up on 12" Hardin
Total Cost: $43.68
Rings - $28.00
Bolts - $0.68
BBs - $15.00
Again, it would have cost a bit more if I would have had to buy the fanny pack, but it was lying around.
Killer Scope Mods #3: Primary Mirror Parabola Correction (Televue Paracorr)
This one isn't really a "mod" per se, but it feels like it to me since the Paracorr stays in the focuser all of the time now.
If you are unfamilliar, the TeleVue Paracorr
, it corrects the coma problem in fast Newtonian scopes by flatening out the field of view by compensating for the parabolic curve of the mirror. And it works very well.
Total Cost: $310.00
Killer Scope Mods #4: A Day At The Telescope Workshop
Today was tons of fun. I happen to live in an area where our local astronomy club (the Rose City Astronomers
) has a few members that host a Telescope Workshop. They have books, advice, tools, and enthusiasm to help folks with scope projects, mirror grinding, Big Dob tracking systems, collimation issues, and anything else you can think of.
Since I have spent the last few weeks "modding" my scope for star party season, I needed some help and advice. What I ended up with was much more.
John DeLacy and Dan Gray hooked me up. I needed new teflon - they had some on hand - "Here, have some." I needed some flat-hear metal screws - they had some one hand - "Here, have some." I needed the screws counter-sunk (?) into the teflon - "Here, use my countersink tool."
I needed help with re-collimating my secondary mirror, they were happy to help. I needed advice on whether or not to re-build my mount and install new altitude bearings because of additional weight on my scope. They said, "Maybe... but try this first," and proceeded to spend an hour helping me modify my current altitude bearings (which seems to have done the trick).
Needless to say, I am grateful. My scope is collimated better, moving smoother on the mount and stable with the new weight of the 102mm mounted as a finder scope.