My input to IYA2009

[AlexN]

Hi all...

I've decided to input to IYA2009 by building a 102mm F/9 Achro refractor, and an Alt/Az mount which will be donated to the local primary school with the hopes of introducing the next generation of astronomers to the wonders of the night sky...

I'll be using a Surpluss Shed 102 F/9 Achro lens/cell, probably mounted in PVC tubing, I wont be building the focuser myself, as I dont have the tools required.. So likely a GSO crayford...

The Alt/Az mount will be wooden, and look much like the Vixen Porta-Mount in design...

As soon as construction has started I'll post up pics and other info about the build..

Anyone who has built something like this in the past who has some hints or tips on the best methods, Please, feel free to post suggestions.. I do hope to make the setup as high quality as is possible so as to not dishearten budding young astronomers.

This will also be the first telescope I've built, but from what I understand it shouldnt be overwhelmingly difficult.

Cheers.
Alex.

[Ian Robinson]

Wont a 5 or 6" PVC tube about 90" long be a bit too wobblely ? , better off doing a thin walled aluminium tube I'd think.

It's a nice idea anyway .... have you approached the headmaster to see if they are interested in taking it and even have teacher who has even slightest idea about astronomy.

[AlexN]

Good thought about the tube... maybe thin walled Aluminium is the go...

Yes I've spoken to the school and they were very keen on the idea.. They have 2 teachers that are into astronomy, who were also apparently very supportive of the idea..

[Ian Robinson]

Originally Posted by AlexN

Good thought about the tube... maybe thin walled Aluminium is the go...

Yes I've spoken to the school and they were very keen on the idea.. They have 2 teachers that are into astronomy, who were also apparently very supportive of the idea..

I'm using a 300mm diam PVC tube in my 10" f4.66 rebuild but it has a low length to diameter ratio so I believe it's rigid enough , if I hadn't been given the offcut , I was going to have a aluminium tube made.

[AlexN]

Any reason you are not considering a truss tube design?

I've been researching the idea of converting my C11 to an open truss for a few reasons... minimise cooling time of the mirror, minimise tube currents due to trapped warm air and hopefully make it a bit lighter...
All my reading seems to indicate that the SCT design is not tolerant to any optical mis-alignment... and whilst Im sure an SCT could be converted to an open truss... Im QUITE sure that I couldn't do it myself..

Planing never the less though... (It would look VERY cool!)

[rogerco (Roger)]

Like your idea, I have a focuser to donate if you haven't sourced one yet, I upgraded the focuser on my SkyWatcher ED80 so have it spare. It only has the single speed nob but is otherwise ok and has next to no use. Drop me a line if you can use it.

Roger