[SJAAboard] Thoughts on requirements for scopes larger than 10"

[Mark Wagner]

On Wed, May 14, 2008 12:12 pm, Rob Hawley \(SJAA\) wrote:
>> To Mark
>
> Keep in mind that there is no scope 28.  The tube is discarded and the mirror is not usable.  We
also have a contract with Albert that he has fulfilled.

The scope Albert is to deliver *is* scope 28, to my thinking - it replaces scope 28.  Albert
received two mirrors, and "contracted" to deliver a finished scope, right?  I'm not interested in
creating any hardship for Albert with that question, just stating what my perceptions are.

> I disagree with your position on Albert's scope. I do not regard this as a boutique item as you
do. Everyone I have talked to who is building a > 10" scope today is using either the Albert
Mark IV or Mark VI design.

I would argue that such may be true in the rather small circle of amateur astronomers we encounter
in our provincially.  But it is wholly untrue in the greater astronomy community.  It is a design
that some will find appealing, especially where there is a hard core following, but more will
prefer building a standard solid tube scope (which is far easier), up to the limits of portability
(which is also very individual).

> While Orion still sells a tubed 12", I would recommend against buying it. It is simply too
unwieldy.  If someone wanted a commercial 12" I would send them to Sam to buy the LightBridge or
to a LightBox or other truss scope. If they could not afford a commercial scope and were
unwilling to build a scope I would advise them to stick to a 10".

I think what you consider unwieldy is a personal preference. The fact that Orion successfully
sells a solid tube 12" scope attests to the fact that there is a market.  The Lightbridge, which
in weight is the heaviest of the 12" class scopes, has not forced Orion to change to a truss
design.  The Orion is 50 lbs for the OTA, 33 lbs for the mount.  The Lightbridge is 53 lbs for the
OTA (which, yes, breaks down), and 39 lbs. for the mount.

> Despite my own preferences, I am not opposed to a tubed 12" being in the program.  My problem
with 27 and 28 was they were both poorly built with bad mirrors. The program has other unusual
homebuilt tubes such as #14, but they have reasonable optics and are in good condition.

Were both mirrors bad, or was Albert able to use one for another buyer?

There is a very simple elegance to a solid tube design.  Set down the base, put the tube on it,
and you're about ready to go.  Viola.  No messing around with truss tubes, separate pieces, and
likely more difficult collimation.  Again, it gets down to what/who the SJAA is targeting with its
loaner program.  Boutique instruments (esoteric designs with very limited production/availability)
are neat, for those with the patience to wait to obtain one, or with the ATM skills to produce one
on their own, but I feel more commercially available and easy to use (plop and view) is more
appropriate to the program, and has a wider appeal.

Mark