6 Inch Ultralite Hiking Dobsonian

[astrolunartick]

Hi again 

About 2 years ago i built a 4.5 inch ultralite fold out travel / hiking Dobsonian. weighing in at about 2.5 kilos with eyepieces, collimator and tools.

Here is a link to a Thread about the 4.5 Dob - http://stargazerslounge.com/topic/237230-45-compact-travel-scope-for-hiking/?hl=compact

This works well but i always felt i could get it lighter and more compact when packet down also me loving building scopes so much i will find any excuse to build another one. This time i have decided to go all metal. Mainly using Aluminium. i want to design the dob as minimal as possible. All i need to do now is design the mount. probably something very simple.  here are some plans and some of the build so far. 

thanks for reading. 

Pete

[astrolunartick]

progress today. 

[laudropb]

Very nice project. Best of luck.

[FraserClarke]

Nice. In the interests of minimising weight -- what purpose does the top-ring serve in the design??  Seems like you could lose those grams without affecting anything??

[Cornelius Varley]

Interesting design. I agree about the top ring. it doesn't seem to be supporting anything. This design http://www.homebuiltastronomy.com/twotube/index.htm takes a similar approach in plywood and metal tube. Notice how the focuser is simply attached to a ply plate which supports the truss tubes.

[astrolunartick]

Thanks for the comments. The top ring is there to stretch a lycra shroud around. I may drill regular holes around the rings to make them even lighter. That's an interesting dob. Thanks for the link Cornelius.

[Chris]

Your other travel Dob looks great. I'm looking forward to seeing how your MKII version turns out, looks good so far

[mapstar]

Nice work Pete and good to see another project under way.

Hope the 20" has had a bit more use of late

[astrolunartick]

I've done a little bit more. The main pole assembly is together although not cut to the final length. This is completely adjustable all the parts side up and down so focuser block, mirror cell and the mounting block can be slid in to place and then locked in place with thumb screws. I've purchased a helical 1.25" fine focus adaptor from Telekop service. That I'm going to slot in to the focuser block. Hopefully this will serve as a light weight fine focuser. It has 15mm travel.

[mapstar]

Looking good Pete and thanks for the update.

I have a friends Altair astro 80mm finder scope with the same type of 1.25" helical focuser on it and it works well.

Watching with interest

[astrolunartick]

Hi again. A small update. I got the secondary holder made and attached the tiny red dot finder that is very small. Not sure how it performs yet. But it is very small. The mirrors are in place and I had a small test out session on the partially covered moon last night. I will give more details at the weekend.

Thanks for reading

Pete

[astrolunartick]

The images have vanished on this thread. Has one one else had this problem. ?

[mapstar]

3 hours ago, astrolunartick said:

The images have vanished on this thread. Has one one else had this problem. ?

I've noticed this on a few threads Pete? Not sure if it's when they updated the format? 

[Gina]

I've had the same.  Also, whole posts

[astrolunartick]

Hello Again to who ever stumbles upon this old topic. I haven't been on here for ages so i thought i would show the complete scope. 

Its been a crazy journey. Trying to design a light weight scope that i can take on long distance hikes. Im a keen walker and do about 4-5 long distance hikes and a smattering of smaller ones through out each year.  Ive made a few light weight scopes now and I found this one ok but there is still a stability issue with the base. which would not take much to resolve. Im just a bit impatient and want to get on with the next project before I have finished the last. 

Any way  I will post some photos of the "Almost finished" Scope in the Next couple of days

[NGC 1502]

 

Thanks for the update. I’m a bit of a DIY scope enthusiast too, and seem to be a compulsive tinkerer. It never ceases to amaze me how long my projects take. Seems like you have  the same problem too, keep at it, you’ll get there ?

Cheers from Ed.

Edit - both of us from Essex, maybe scope DIY is a bug you can catch ?

[astrolunartick]

Hi Ed.  I have so many Projects on the go at the moment and so many ideas. I need to clone myself. 

I see your in Essex. Do you Get to the Dengie much?

[Gina]

I could do with cloning myself too ?

[NGC 1502]

2 hours ago, astrolunartick said:

Hi Ed.  I have so many Projects on the go at the moment and so many ideas. I need to clone myself. 

I see your in Essex. Do you Get to the Dengie much?

 

My club, Castle Point AC has access to private land on the Dengie marshes. The gate is now electronically controlled as previously folk without permission went there, now they cannot, which is good because occasionally we’ve been disturbed by headlights from unauthorised people.  We haven’t been so far this year, but we are planning more visits.

I think there may be public access to some parts of Dengie, but haven’t investigated that.

HTH, Ed.

[astrolunartick]

Hi Folks here are the latest photos as i promised. As i said in my last post the base is a little wobbly but that will be easy to remedy. I just need to get it back to my workshop and have a night of tinkering. It has no light shroud or baffle. I have a aluminium ring to go on the front end and i was going to stretch some black lycra or some kydex round it but ive not got round to it yet. Besides that the scope works well. the views of the moon the other night were very nice for a 6 inch Newtonian.  I use a Skywatcher HyperFlex -7E 7.2-21.5mm eyepiece with it, as this set up is all about keeping pack weight down. I am use to using 82 Degree Explore Scientific eyepieces so this Skywatcher eyepiece can be a little narrow when zoomed to 21.5mm. But thats me just being fussy i suppose. The ultimate test is when i pack it in to my ruck sack and go for a hike. I have done this once. When i walked the Cotswolds a couple of years back. It was a bit trick to set up and not as satisfying as my other Ultralite backpack telescope design but it did do the trick.

Thanks for reading and Clear skies to you. 

Peter  

 

 

 

 

 

 

 

 

[Stu]

Lovely scope, a really interesting project. Nicely done!

[Gina]

Very interesting design, beautifully made.  ??

[tooth_dr]

Very nice. Thanks for sharing. 

[Chriske]

Nice scope..
It could do with some blackening 'here and there' indeed. Especially when observing the Moon contrast will go down as it is now...

[Gina]

That's true.