Celestron 102mm F5 (first impressions)

"Alan Charlesworth" wrote in message
...
In article ,
"Stephen Paul" wrote:

I also tried them on a Starguide 4 mount:
http://users.net1plus.com/spaul/astroequip/SG580.jpg


How did the drive (it looks like the 5" Nexstar single-fork mount) like
moving the extra weight of the ST-80? How did you attach it to the 5"
SCT? Did you add counter weights to the 5"?

I have wondered if I could attach an Orion 80ED to a 8" LX-90 without
overloading the drive.

If you mount the ED80 on top of the LX-90, you simply add a sliding
counterweight to the under-side. Losmandy makes both the top dovetail bar
and rings, and a bottom dovetail bar with weights. Ken's Rings and Things is
another place that might have a solution for you.

As for how my contraption worked out. Well, let's just say that I wouldn't
want to bounce it to hard. The adapter plate to mate the C5 to the Starguide
4's mount (not an N5/N8 mount) is a piece of soft pine g. If I ever wanted
to make this a permanent piece (to mount the C5 only), I would have someone
machine me up one from aluminum stock. The SG4 mount is more than adequate
for the C5. My only complaint with it really, is that the tracking is only
sufficient for visual and requires that you man the hand controller at high
powers. I added the updated Nexstar hand controller to this mount a few
years ago, and it improved the performance and usability of the mount enough
to justify that added expense.

My biggest concerns were the pine adapter letting go, or the cast aluminum
arm cracking under the weight of the ST80 hanging way out there (so I took
it off after the fun was over). The mount was capable of moving both scopes
and getting on target without any trouble. I did need to add more pressure
to the clutches by tightening up the bolts, but I've had that mount apart so
many times that I could do it with my eyes closed.

The ST80 is mounted by doubling up the the rings. The C5 rings and the ST80
rings both have the 1/4-20 threads for a piggy back camera. I joined them
there. I have to admit that getting both scopes to point to the same object
wasn't completely accomplished, but the wide field of the 80, provided a
sufficient fudge factor. Using a low power eyepiece in both scopes, it was
possible to get any object in both scopes at the same time. All I had to do
was man the handcontroller when looking through either scope while moving up
in power.

Anyhow, like I said, all of that was fun for me. I enjoy coming up with
ideas and making them work. My next project will be barrow handles for the
Starfinder Dob. I'm intending to use four of those metal brackets that one
uses to secure a door with a 2'x4'. I'll mount them upside down, and the
barrow handles will them simply slide underneath. I'll put notches in the
handles to keep the scope from sliding toward the wheels when I lift. I'm
then going to add a couple of eyebolt and hook style latches to the inside
of the base so that I can lock the OTA into an upright position for
transport. That way I can just roll the entire scope out onto the back lawn.

Stephen Paul