DIY Single Strut Dobsonian

[asteria]

Hi there - here are some pictures of the single strut dobsonian that I built a few years ago. It's a bit crude (I'm no cabinet maker) but it works. It could benefit from some refinement - one day!

Any questions do ask. (Yes - it is made of chipboard.....out of a skip. There, we've got that one out of the way.)

150mm, f8, if I remember correctly.

I made it to take to Australia - fits in a suitcase. The strut has to travel separately.

 

Edited September 28, 2019 by asteria

[markse68]

That’s super cool- does it hold collimation well? And does the secondary bounce around a bit? Not sure if that’d be any worse than my drain pipe Fullerscope where the whole thing wobbles around a bit too much on its dob mount though tbh  🤔😉

[wormix]

I love it!

Was eying an 8” mirror the other day and wondering if I had the skills to do something with it. 

[asteria]

Hi there - thanks for the interest. The scope actually works really well. I think the longer focal length helps as the tolerances are not as tight as they would be with an f5 mirror. I ran out of time with the secondary, so essentially the mirror is mounted on a wooden block, which is attached to an aluminium strip which allows for collimation. However, once adjusted, it will hold it's position within the session quite well. The balance is also pretty good, although the 'tube' will slip in the mount if the altitude is low.

I think, as a proof of concept, it was a success. With more woodworking skills it could be made to look more sophisticated, but I quite like the aesthetic.

I'll take some pictures of the scope broken down, so you can see what I was aiming at with the portability.

[asteria]

Here is the first prototype - this is a shocking design. Don't even think about trying this at home! With the cardboard prototype you can see the problems immediately. Terrible deflection. The rotation of the tube is not so apparent in this photo, but is a real issue. The video shows the bounce and wobble. Back to square one.

 

DSCF0561.AVI

Edited September 29, 2019 by asteria

[asteria]

Prototype two. This is a much better design, and takes its inspiration from Ross Sackett (http://stardazed.com/). Of course the main difference is that he is a craftsman and I'm a bodger.

This is a much better design but the secondary mount and focusser board is way too heavy. However, the basic design elements are now in place.

The final picture was the primary inspiration. The 'punk' aesthetic gave me hope that i could build something like this too.

https://www.instructables.com/id/Airline-portable-8-Dobsonian-telescope/

Edited September 29, 2019 by asteria