14"/360mm truss dob

[Moonshane]

that's a simply fantastic scope.

[swamp thing]

Very nice Alan. Look forward to seeing it in the flesh.

Lets have some more pics......please

[Rustysplit]

Thanks for the kind comments guys. But to be fair Shane, it is not a fantastic scope yet. It could all be style over substance for all I know

I was going to stain it black initially, but now I rather like the natural look.I might just stain the parts that need to be black and leave the rest as is.

I will try and get some more pics next week, but work is hectic at the moment, so may not get any more done for a bit. I need to find time to start figuring the mirror as well

[Rustysplit]

Gary, I used aluminiumwarehouse.co.uk

The size I went for is 3/4 x 16swg. The trial fitting showed it to be lovely and rigid, and it still has about 200m to come off it yet, so I think perfectly fine for an f5scope. My tubes will be about 1450mm long iirc.

[8kids]

Cheers Alan.

[fwm891]

That's a handsome looking pile of timber. I'm in the process of purchasing all the necessary bits for my own truss dob (i've bought a nice 12" mirror) where did you get your ali poles from and what gauge have you used.

Gary.

Gary check out TV aerial masts in B&Q. There are different diameters but the 1 inch ones have a very thin wall so you won't add too much forward weight to the assembly which will make it easier to balance out.

I used 6 rather than 8 poles to further reduce the front loading and keep the CoG that much lower.

[swamp thing]

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I was going to stain it black initially, but now I rather like the natural look.I might just stain the parts that need to be black and leave the rest as is.

FWIW I completely agree. Leave the natural beauty of wood alone.

[estwing]

that is very nice mate,must be very happy

[8kids]

Gary check out TV aerial masts in B&Q. There are different diameters but the 1 inch ones have a very thin wall so you won't add too much forward weight to the assembly which will make it easier to balance out.

I used 6 rather than 8 poles to further reduce the front loading and keep the CoG that much lower.

Thanks, I'll have a look.

[Rustysplit]

Little bit done at lunch today. Sorted out the upper truss attachment brackets.....

Cut away as much as I could to save a little weight.

[fwm891]

Alan, Rather than two securing screws can you not substitute a clamp bar arrangement such that each tube has a hole or slot near one (or both) ends into which the clamp is fitted and a single knob tightens both in place?

aka:

Just a thought...

[swamp thing]

Looking good to me.

It looks like the trusses stay in pairs? Nice little touch.

[Moonshane]

the clamps look great. I'd recommend a slightly longer handwheel to allow for less finger tip tightening. I am considering making my next ones with quick release clamps similar to push bike wheels a bit like these

and maybe even some of these at the bottom

[Rustysplit]

Francis/Steve The whole 8 truss tubes will remain attached together, so that I have 4 handwheels to tighten top and bottom. I have to thank Shane for that idea!

Shane, I looked at those too. I am trying to really keep the weight down at the top as my mirror is so thin and light. I think they are a great solution though for the uta fixing.

[8kids]

the clamps look great. I'd recommend a slightly longer handwheel to allow for less finger tip tightening. I am considering making my next ones with quick release clamps similar to push bike wheels a bit like these

and maybe even some of these at the bottom

I was given a set of these with the mirror I recently bought, along the same lines. http://www.astrosystems.biz/utlltl.htm

[Rustysplit]

They look great. Really neat solution. You got me thinking now........... No stop it. I will stick with the plan and see how the weight comes out. Plenty of time for upgrades later

[Moonshane]

very very nice.

[Rustysplit]

Ok, I have made some real progress with this now. I picked up my self ground mirror last week, and managed to get the not yet finished scope together to be able to test it.

The woodwork is unfinished as yet, and a shroud is in the pipeline. I knew from the start that the very light primary combined with a tiny mirror box would cause balance issues, it does, but there is room at the rear of the mirror cell to add a ballast weight. We tried it out last night and with a little extra help from a bungee cord, it works!!

The mirror has turned out very nicely, and with a little tweaking of the friction loadings, the scope works as expected. It all packs into the boot of the car in 1 stack, with just the truss tubes inside the car.

I will post more detailed pics when I have taken it apart and lacquered it all.

[swamp thing]

Looks real sweet Alan. nice one. Looks like you beat me to first light

I've still a bit to do yet.

[Rustysplit]

Cheers Steve. It all happened in a bit of a flurry. It is gonna be hard to take it all apart again now!! It has to be done though. This will mean I can get up to RC easily. Looking forward to it and meeting you, and giving you those beers

[8kids]

Nice looking scope. I hope your going to post close up shots of all the details. Also is that the Revelation hybrid focuser, what's it like?

Gary.

[estwing]

speechless Alan..just stunning.

[Astrobits]

Very nice looking scope there Alan.

Glad the images are as good as you would have wished for.

Well Done.

Nigel

[Beulah]

What an amazing achievement for someone who has not ground their own mirror before! I am totally stunned. Can't believe you have made this so quickly.

I'm trying to find a solution to smoothing the rough edges of my 14" blank without losing the circular shape and I'll be off myself.. Barkis (Ron) will be ashamed that I have't yet got round to grinding it....

[JamesF]

That really does look lovely. An excellent achievement

James