Why can't someone build?

[rowan46]

A very portable push to alt az mount capable of taking an 80mm triplet refractor for the same price as a got to alt az mount. How hard can it be?

[ronin]

Scale of production.

An observing night I went to had 8 or 9 goto's and one scope on a Vixen Porta Mount.

If scaled up and still at 10:1 then most likely cheaper per item to make a run of 10,000 goto's then 1000 manuals.

Someone at the recent IAS had a "remake" of the Sky-T or EZ-T mount that would do what I think you are asking, just not a clue who. But that sounds as if it is what you are thinking of. They are not made any more possibly because the demand was low.

Mechanically it is possibly less cost to use the motors to act like a clutch then it is to manufacture a clutch mechanism.

[DirkSteele]

The answer is they can. It is called the Tele Optic Giro Mini. I only spoke to Rupert at Astrograph (UK distributor) a few days ago about this very subject and he confirmed it is more than up to the task. The link below shows pictures of it holding the APM 80/480. It can be done without a counterweight but is smoother with.

http://www.tele-opti...ic-gr-mini.html

Clear skies,

[rowan46]

The answer is they can. It is called the Tele Optic Giro Mini. I only spoke to Rupert at Astrograph (UK distributor) a few days ago about this very subject and he confirmed it is more than up to the task. The link below shows pictures of it holding the APM 80/480. It can be done without a counterweight but is smoother with.

http://www.tele-opti...ic-gr-mini.html

Clear skies,

Its lovely but by the time you have added encoders control box tripod you are nearing the price of an heq5 rather than say an se mount

[DirkSteele]

I misunderstood your request. Thought you meant completely manual, not digital setting circles. Though in this case, any decent photo tripod you have would be up to the job as the Giro is 3/8 threaded so perhaps the cost would be lower for many as that item may already be owned.

However, you raise a good question why not....

[osbourne one-nil]

Is the Televue Sky Tour the closest thing there is? I've often been tempted by it in the past, but the technology seems quite old, although that probably doesn't matter at all!

[Macavity]

There are plenty of "Giro" type mounts around? I was a happy owner of a Giro III for a long time. I made an azimuth setting circle (calibrated to 2 deg) and stuck a Wixey on top of the scope to read Azimuth to 0.1deg. Level, do a "one-star alignment" (The Azimuth circle was movable) and away you Go! I did begin to lament the lack of slow motion drives though. Also, for best functioning, the desirability of counterweights. I am looking vaguely at a Vixen Porta II - Something for the future maybe...

Oh yes, and doubtless an "I-Whatever" to run "Skysafari 3" etc.

Another project with open-ended financial requirements...