Tuesday, June 12, 2012

My new tripod

After seeing an article on building a tripod from recycled aluminum crutches and knowing I had two of the things in my garage junk bin, I began hunting for a (cheap) additional one.  I found one for $2 at a flea market a few years ago.  This month I finally got around to finishing the project.  Wow is all I can say!  It's nice.  I put it to work tonight as a nice, stable, level, portable platform for my traveling ETX70.  I still need to finish (paint) the wood parts and drill a couple of holes to bolt the ETX to the tripod so it doesn't accidentally get knocked off, but other than that it did the job flawlessly.  I even got to try adjusting the legs when my target for training the motors was below some nearby bushes.  After fiddling with it a bit just at sundown, I set it up in my 'observatory' at the end of the deck and waited for dark.  I had a bit of trouble aligning the scope at first.  Not sure why it didn't want to align on two stars.  I finally gave up and used a one star alignment and all was well after that.  I wanted to see how well the ETX would do on globulars so went after M5 and added M4 for good measure.  I found Antares quickly enough and told the ETX to find M4.  Bingo, right on. M4 was a very conspicuous glowing ball forming a nice triangle with Antares and Sig Sco.  I was not able to make out the much dimmer and smaller NGC 6144 globular though.  Next I told the ETX to find M5.  It zipped right to the neighborhood, but no cigar.  I slewed the scope a bit with the handbox and there it was!  Right above a little comma shaped asterism of 5 stars including 4 and 6 Ser.  5Ser is just above and anchors M5 which is another glowing ball somewhat smaller than M4.  I was able to see M4 and the asterism in my 7x50's but not several 8 and 9th magnitude stars grouped with the asterism that I was able to clearly see in my ETX.  The 7x50's compensate for their lack of light gathering capability with a FOV that is about 2x that of the ETX with a 26mm EP.
All throughout this process, the new tripod worked just great.  I tried tapping it in several spots and there was no noticeable vibration.  I might add that I have my 12v power supply hanging from a hook on the tray and that seems to stabilize it very well.  I also get a nice little green spot on the ground from the 9v adapter!  The tray is a simple triangular board made from the same 3/4" plywood at the top and serves well to hold the handbox and other small items.  I used my Denver Chair with the new tripod and it worked great too.  I'm not sure I'll haul it around since it's heavier than the tripod but they do make a nice pair.
Bottom line:  the ETX still requires much more fiddling around to find things than the 8"dob but performs just fine in a dark sky environment and tracks well enough to share the view with others.  I could do with a bit more focal length (for magnification) but can't have everything I guess.  The tripod is definitely part of my astronomy travel bag now.

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