Home made telescope How hard ?

[Mr TamiyaCowboy]

have been pondering this in my mind for a while now.

how hard can it be to make a telescope for a total newbie like myself ?

my idea is a small 3 inch mirror and secondary @ around 700mm

but not in a standard tube design but an open truss system.

i have seen plenty of large truss telescopes on google but never seem to see small baby sized truss telescopes. but would like to make my very own.

is this something a newcomer to the hobby could do. i would purchase a mirror set then build a framework around the mirrors size and focal length. i know tube would be more simple but truss scopes look so cool and less bulky.

could you pro's point me in the right direction with advice and a fairly simple truss layout for a small 3" @700mm focal please.

[JamesF]

I'd suggest that a cardboard or other solid tube would make more sense for something that small. garethmob just posted about using exactly that mirror, I believe. At those kind of dimensions a truss is probably going to be awkward to make small and light enough.

James

[perrin6]

I think truss tubes are used for 2 slightly different reasons-

1) enabling large telescopes to break down into more easily transportable units

and

2) for scopes that would be too heavy to lift if made using a solid tube

Why exactly do you want to use the truss design as there are much easier options for a 3 inch scope plus why go for such a small size ?

[username]

It's not a truss but this thread from the diy section may be what you're looking for

http://stargazerslounge.com/diy-astronomer/183838-my-cheap-cheerful-3-diy-dobson.html

it isn't mine though just so you don't get confused by the link title

[Mr TamiyaCowboy]

smaller as it is more cheaper. and also a talking point.

truss because i have never seen small truss scopes unless i count the heritage 130.

smaller is more simple, smaller mirror's so less risk to damage, also a 12 inch build would be a lot for a newcomer to take on. so my thought was a smaller telescope would be slightly more easy to build and require less tools.

[jimmyjamjoejoe]

Maybe threaded rods for the trusses, they can flex a bit over big lengths but given the short length and low weight it should be fine.

Unless of course you mean a sliding truss like the flextubes... That'd be tougher, but still not complicated. Just some metal rods passing through a block with a screw in the side of it, tighten screw to grip the rod...

Been thinking of building a scope myself, and just seen an idea in another thread for a binoscope...

[Mr TamiyaCowboy]

i was thinking more a recycled telescope. using stuff people throw away/give away.

the truss tubes made from old carbon fishing poles and the likes. the focuser could be salvaged from an old knackered SW / celestron.

a lazy susan type bearing could be used to allow finder ring and secondary to rotate around for comfy viewing angles.

[Moonshane]

go for it I say - what can go wrong?

I am converting a 6" scope (again not normally associated with truss based systems) into a suitcase dobe as I want to try and make the whole unit small enough to take on holidays. http://stargazerslounge.com/diy-astronomer/184525-6-f5-suitcase-dobsonian-project.html or http://stargazerslounge.com/2255001-post21.html

[Tyr]

I'd thought that would make a cool project too, I had been looking at some of the little mirror sets on astroboot as source material.

But I'd come to the conclusion I currently have enough other unfinished projects though

If it was small and light I'd have thought a simple plywood construction with bits of dowel / strip wood and light ply you can get from most DIY stores might do?

Something I'd definitely approach from a learning experience perspective though. damn it I sense another to be unfinished project.

What were you going to do about a focuser and adjustments for the mirrors?

Tyr

[swamp thing]

How about this little beauty:

http://stargazerslounge.com/diy-astronomer/137623-4-5-f-4-4-babydob.html

Work of art if you ask me.

Regards Steve

[Gina]

This is something I'd like to have a go at but it wouldn't be for a long time as my list of projects is already very long

[Tyr]

How about this little beauty:

http://stargazerslounge.com/diy-astronomer/137623-4-5-f-4-4-babydob.html

Work of art if you ask me.

Regards Steve

Very cool

[swamp thing]

This is something I'd like to have a go at but it wouldn't be for a long time as my list of projects is already very long

Funnily enough I know exactly what you mean.

[Mr TamiyaCowboy]

focuser i would like to rotate in the upper focuser/spider ring around 180 degree, so hence using a lazy susan bearing on the upper section. this could allow the focuser and spider to rotate around 180 degree , bit like rotating a newton tube on an eq mount.

mirror adjustments i will just use those built into the mirror cell.

some smallish weights could be added to balance the scope.

maybe 3 inch is a little small but i could always upsize on mirror depending what is around on AB at the time.

right now i am brain aching on ideas and what i can use for parts.

[Gina]

Something I'd like to try is making a long FL scope for planetary imaging. No need for large aperture for light gathering though bigger would give better resolution I grant you. I'm wondering if I could mount the webcam directly in the spider, doing away with the secondary mirror. I would have to work out how to focus and also how to collimate.

[JamesF]

You could fit a focuser instead of the secondary unit. Obviously it would need to be something fairly slim and lightweight, but it would mean that you'd be able to drop in an eyepiece or collimating laser instead of the camera. If it had an r&p drive on the focuser you could actually mount a motor behind the camera to drive a worm on the rack.

Another problem is routing the cable(s) for the camera.

James

[Mr TamiyaCowboy]

wifi camera, could house a 9v PP3 battery other side of focuser to give some balance. no thick wire just thin stuff you could blend onto the back of the spider vane.

fishing poles are tapered so could become a problem overloading the top section. saggy secondary ( i had to chuckle).

[garethmob]

I'm doing one of these. It's a present for a mate but also a basic which I hope to scale up to a flexible for the coulter I have:)

I thought of a truss but it's just such a small diameter I didn't see any gain. But it is Long. Have a look in my thread I posted I'm on my phone so unfortunately I can't

I know what you mean about long list of projects. I'm currently selling a lot of nthem now lol. Just too many

Sent from my iPhone using Tapatalk

[Gina]

You could fit a focuser instead of the secondary unit. Obviously it would need to be something fairly slim and lightweight, but it would mean that you'd be able to drop in an eyepiece or collimating laser instead of the camera. If it had an r&p drive on the focuser you could actually mount a motor behind the camera to drive a worm on the rack.

That's a good idea

Another problem is routing the cable(s) for the camera.

James

The cables can be very thin - just USB and a tiny servo motor for focussing. So I don't think that would be a problem.

[Mr TamiyaCowboy]

the base i think should be a dobson type.

i have been pondering over setting circles mainly ALT /AZ. my baby dobson has none but i use them all the time on my EQ1 mount.

i decided that circles should be added, then came the idea. illuminated setting circles.

using a couple of those rubbish red dot sights, stripped down i could mount one into the base and allow it to shine onto a purpose built setting circle. using the turn switches to control both power and brightness will be handy,

being red will also help with light pollution. a neat little idea for something usually replaced straight away.

i also think a sliding truss system will work better like the skywatchers but using three legs and not two. help combat droop.