Re: ATM Toy-Scope

["Thomas" <tomjan@ozemail.com.au>]

And this is what ATMing is all about, the adaption, and propergation of
beautifull instruments to looka t the night sky.

I hope this "toy" brings a young mind to a life time of wonder, and
marveling at the beauty of the sky.

Good work and a great story.

Clear skies, Thomas.
http://www.tjanstrom.com
http://www.norsewines.com.au
----- Original Message -----
From: <IAPDK@ADMIN.DRAKE.EDU>
To: <atm@shore.net>
Sent: Tuesday, January 13, 2004 12:03 AM
Subject: ATM Toy-Scope


>
> After Christmas I made the rounds of the local thrift shops to
> see if any goodies had made there way in - sure enough!  First,
> the DAV had a 700mm 75mm refractor by Edu-Science for $6.00.
> Unfortunately it was missing finder, eyepieces, and one tripod
> leg so I decided to pass.  But the Council of the Blind Thrift
> had a 700mm 75mm reflector with one eyepiece, 3x barlow (450x
> possibilities!) and a complete tripod mount for $6.99.  I know
> a family with a young boy that really, really wants a telescope
> so this one I bought.  Thus begins a journey.
>
> A little research on the web shows this scope, also from
> Edu-Science, for sale at Toys-R-Us for $99, usually pictured
> in the ads with the back end pointed at the sky, so my
> expectations are limited, however I am an experienced ATM
> aren't I?  Make telescopes out of trash and scrap?  Surely
> I can make a telescope out of a telescope.
>
> A list of things obviously needed:
>
> - the mirror is dirty - hopefully it hasn't been handled too much
> - the mirror cell is missing all three spring-loaded collimation
>   bolts and is held on with scotch tape.
> - one of the internally threaded spider tensioning bolts is missing
> - there is no finder scope to go in the nice finder mount
> - the mount is a little wobbly - well a lot actually
>
> The mirror cleans up beautifully after soaking in detergent
> which is a big relief.  And I find a compression spring in my
> collection that is cut into three parts to match three thumb
> screws, and the cell is safely mounted and adjustable.
>
> The spider consists of three #4/40 bolts.  I find a nylon spacer
> in a box that has a #4/40 internal thread, mount it in the drill
> press and grind it to size, cut a thread on the outside for
> a nut, put a compression spring on it and we are in business.
> Looking through the focussing tube I discover that the secondary
> is about half a centimeter too low, but a little fiddling with the
> screws brings it up ok.  I feel a twang of empathy for the previous
> owner.
>
> After getting the optics all aligned as best as possible peering
> in the focusing tube I take it out for a look at the night sky.
> It won't focus!  The mirror focusses short.  Well, that explains
> why it was donated to the thrift, there is no way your average
> toy-scope buyer could fix this little problem.  But we are ATM!
> I remove the mirror cell mounting ring and cut an inch off
> the back of the metal tube.  Now it works fine and the focusing
> tube no longer intrudes in front of the mirror.  With the 20mm
> eyepiece I can see a tiny ring on Saturn.  For now I resist
> using the 3x barlow which consists of a simple lens in a tube.
>
> The mount is still a bit wobbly, but with the legs left at their
> shortest length, and all the adjustment knobs set to just the
> right tightness it is bearable.  Though I have to kneel in
> the snow to look in it because the focuser is mounted on the side
> instead of the top :-/
>
> A while back a relative gave me a pair of binoculars with
> nice optics and a broken center-post.  With one eyepiece and
> lens and a couple pvc plumbing parts I make a finder-scope
> complete with copper-strand cross-hairs.  Easier than expected
> once I got started.
>
> As a bonus the tube has a cap for the upper end which has a
> 50mm opening, so I glue a square of solar filter material
> over it and now it is safe to use on the sun.  It is very much
> dimmer than in my 8-inch but the spots are unmistakeable.  I
> also add a 12mm eyepiece left over from another adventure.
>
> The best part of this gift will be a book, The Backyard Astronomer's
> Guide, by Dickenson.  I would recommend it to any new Astronomer.
>
> Even new this scope was not worth $99, but $6.99 is just about right.
>
> Paul Kline
>
>