PDA

View Full Version here: : Tubes for Newt?


xrekcor
10-04-2005, 04:35 PM
Does anyone know of someone in Oz who makes or supplies OTA tubes for newtonians

thanks in advance for any info

ballaratdragons
10-04-2005, 04:49 PM
Hi Rob,

A lot of places in Oz sell tubes. Here is one example of a place that will make custom tubes.

http://www.telescopes-astronomy.com.au/telescopes036.htm#tube

I did a quick search for you and the more popular Astronomical suppliers in Oz also sell them ready made.

You can also go to sheet-metal workers and they will roll any size tube you want. You get to pick the material thickness (light, heavy, etc.), Aluminium, colourbond, Gal etc., the colour, length, diameter. Most don't charge a lot for a quick 'one of' job using a small amount of material. They could possibly roll tube rings at the same time to match the diameter.

Hope that helps, Rocker-boy! :D

stringscope
10-04-2005, 05:03 PM
Rob,

Do you have a specific purpose in mind?

The reason for my question is:

If you are looking at building a Newtonian from parts then you can obtain excellent results using "sonotube" aka concrete formatube. This is cheap, easy to work and commonly used. I have also seen some excellent home made scopes with aluminium tubes.

Cheers,

gbeal
10-04-2005, 05:07 PM
Yep, me too. Normally use sonotube/formatube, but more recently used aluminium sheet, and had it rolled. Lined the interior with cork sheet, and flat blacked it. Perfect. Cold to touch though

xrekcor
10-04-2005, 05:48 PM
Thanks for the replies

sonotube I think I may of seen this, is it light weight?

Last weekend when we had excellent weather. I did a couple of over nighters. Well sunday afternoon I was napping (must of been the beer and Deep Purple) and my scope was still setup iin the yard. When I woke there was a gale blowing and had blown over my scope. Lucky it fell on the side away from where the focuser and Finder are located. But the tube
did suffer a lil bit of warping and now it doesn't rotate in the rings when they are loosened. More of a pain in the @$$ than anything so I'm thinking of a new tube and perhaps designing a ring system that can easily be rotated. Apart from that the scope didn't suffer to much damage and still columates well. But I wonder if when I rotate it now and retighten the rings if this doesn't move the secondary ever so slightly. Not that I have noticed it.

Thanks for the website

stringscope
10-04-2005, 06:04 PM
Rob,

Any chance of some photos of the damage??

I notice your scope is mounted on a tripod/GEM. Do you want to keep using this mount or, for ease of use, do you have any thoughts about a dob. I am suggesting this as your scope probably has a thin wall steel tube that would probably be difficult to replace with formatube or aluminuum and still use the same tube rings. OTOH you could use the existing optics and build a new dobsonian scope around them.

Another alternative is to visit your local automotive panel beater for advice on repairing the existing tube.

Cheer,

xrekcor
10-04-2005, 06:59 PM
Ian,

Yes! I did think of turning it in a dob, would be a great scope for my son to use as a dob. But I think my back might give me problem bending over it all the time. I'm actually getting a dob soonish it will be a 12" f/5 which would be a better height for me.
I'm getting as I want something a lil bigger while I save for an 18"-25" dob of sorts.

regards

xrekcor
10-04-2005, 07:03 PM
Ian,

The damage cosmetically is not very noticable so photo's wont show you much, the lil dent it had was easy to push out. It's the slight warping of the tube which makes it sit a lil tight in the rings.
I've tried to gently kinda squash it out.

I'm going to look into making a rotatable ring system... cheap! lol

stringscope
11-04-2005, 05:51 PM
Rob,

Sounds like it could have been a lot worse. Probably best to just leave it and work on the rotating rings.

Hey, I bet you can't wait for the 12" dob!

Cheers,

xrekcor
11-04-2005, 06:23 PM
Ian,



Actually you given me an idea perhaps I could design it with a new tube of sorts with a rotating ring setup, and also build a Dob style mount with a cradle I can lock the OTA into. That way my young son could use it as a Dob.




Yes! it will be awhile off yet. Still have EP fever lol.

Well the sky is waiting and it's looking real good!! hopefully we wont get interupted tonight

Clear Skies

Regards