Aluminium extrusion dobsonian mount

[Damo1965]

Last year I made the decision to mount my SW 150PDS on a dob mount - the old EQ3-2 I had was just not up to the task anymore and, despite overhauling it the flimsy tripod was certainly holding my visual observing back.

Like most who chose this route I bought a large piece of 18mm ply and set about copying all those who had gone before and knocked up a pretty decent base which was just the right height for my seated observing.

However, the damp winter had a detrimental effect on the uprights and by last month I noticed that both were warping outwards at the top - enough that the OTA was at risk of slipping off.

A rebuild was in order and I decided to try using aluminium extrusion - the 2020 slot stuff - some of which I had lying around. I reasoned this would not warp, could be made very accurate without too many tools and would be lighter than the original.

Having read on CN about a similar one, but using 3D printed joints (I don't have access to a printer) I thought I would give it a go. It was great-ish. 

At first I used all 2020 extrusion, but like the old SW tripod found that vibrations were an issue so have included some 18mm ply as mass damping. 

It's lighter and stiffer and gives me the option of changing it to suit different requirements in the future - OTA size etc.

 

Edited March 2 by Damo1965
Mistake

[PeterStudz]

Great ideal and a good job. I like it.

[maw lod qan]

It does look really good.

At least now I know why there's so many clouds!

I thought it was me working on an observing chair!

[Steve Ward]

Nice job.

But I have to ask the question ... who on earth suggested to you that a 250DPS would be OK on an EQ3-2  .... ???

 

OK ... cancel the above , I see that you made a glaring error in the opening sentence of your post.

 

Edited March 2 by Steve Ward

[Damo1965]

Oops - should read 150PDS

[Steve Ward]

8 minutes ago, Damo1965 said:

Oops - should read 150PDS

If you click on the 'three dots' top-right of your post you should get a dropdown with the options to  Report , Share or Edit .

The Edit box lets you address the mistake ... 😉