Small 3" newtonian project

[moflaher]

HI All:

I have just ordered a 3 inch, 700mm fl mirror and matching diagonal from astroboot, for about £8.

My project is to prove to myself if I have the skills to build a newtonian dob. So starting small...

I found this page for telescope design : NEWTONIAN TELESCOPE DESIGN PLANNER (I.E. version)

The next step is building the OTA.

Option 1: PVC pipe. The question where to buy (4 inch dia)> I went to B&Q but I couldn't find anything that could be useful, although I still need to see the actual dimensions of the cell.

Option 2: a very simple truss tube setup. The question: is this too challenging for a first attempt?

For both options the mount will be a dobsonian box.

I do not expect to compete with the HST, but I will be more than please to end up with a reasonable scope and lots of experience.

Thanks!

Any advice, websites, pipe vendors or ideas wellcome.

[Hypernova]

I had a look at those very same items on astroboot and thought about doing that also. Hope it pans out alright

[yeti monster]

A baby lightbridge that can collapse into a briefcase would be cool, me thinks........

[Peter Drew]

Was that a small 3" Newtonian or a small project?, I've yet to see a big 3"!. Joking of course, it looks like a very reasonably priced starter in telescope making.

[moflaher]

A baby lightbridge that can collapse into a briefcase would be cool, me thinks........

Good idea.

Any links for blueprints/similar projects?

Thanks!

[Moonshane]

I've never done it but I bet one of those black curtain poles with one tube that slides inside the other would be good and I bet you'd get 3 or 4 sets of struts from one curtain pole. maybe you have something in the shed or could find something at the tip? you'd need a rod or something to hold the middle (unless you got it in a single length depending on the focal length of the primary) and you could flatten the ends, drill a hole and then fix with hand knobs/thumbscrews? again lots on Astroboot. would 4" soil pipe be good for the tubes? I bet if you scour skips in the next few weeks or ask a builder nicely, they'll have some bits to spare. it's quite stable too, light and easy to drill.

[NGC 1502]

Hi, a great place for DIY telescopes is http://stellafane.org/tm/dob/index.html all sorts

of interesting projects. Regards, Ed.

[Hypernova]

Just noticed that there is another set of these mirrors on sale for £12 inc postage.

[moflaher]

Thanks to everyone. I thinking along these lines:

a) The "safe way": a pvc tube and a dobson rocker box using a lazy susan.

a "truss tube" portable: use pvc tube sections to house the primary, a separate one to house the secondary, and spare pole tents to conect both. Of course, the cost of the project is now similar or over skywatcher was asking for their 3 newtonian sold during the IYA. So I am still thinking on doing this cheaper.

Thanks, and if I ever finalized this, I will post photos.

[Cornelius Varley]

To simplify the truss further, you could adapt this Twin Tube Telescope down to a suitable size. Wickes sell small aluminium tube, channel and box sections to construct the trusses.

Peter

[John S]

Single pole design here www.stardazed.com/MoonsilverI.htm

[John S]

Now the link wont work Googling "Moonsilver telescope" will.

[Cornelius Varley]

The moonsilver looks as minimal as you can get Moon Silver

[John S]

There is a commercial version of Moonsilver Google the "Litescope" but that site is not working either. But there is another metal version "Scopemankit"

Its a remarkable design biult on the concept one larger tube is stiffer than many except that is in a truss design.