12.5 inch newtonian cell constuction

[skeltz (Rob)]

Hi all yeah im still alive!been a bit busy lately but things have calmed down now.
Any way i have been constructing my cell to hold my zambuto mirror which is in customs as i speak!!!!carl zambuto is extremely pleased about the way this mirror turned out and that makes me extremely happy.
Anyway i will put a link in here http://www.pbase.com/skelty/equipment_and_observatory
this way you can browse the pics of my cell making journey.
It is a triangle shape with six flotation points the cell will be siliconed on to it.
I should add that weight wasn,t really a big concern of mine as it will be going on my titan mount.
So have a look and feel free to ask if you have any questions....and oh HAPPY NEW YEAR ALL ,....CHEERS ROB

[GrahamL]

nice rob

[DaveGee (Dave Gault)]

Hi Rob,

I love the plywood tube. That brings back memories for me...
http://users.tpg.com.au/users/daveg/Tube.html

What was the thickness of ply did you use and how many layers?

Regards
DaveGault

[skeltz (Rob)]

Hi dave,well you were the inspiration for my tube.
I had seen it on your website so the construction was brimsply 3 sheets of 1.5 ply which itself consists of 3 x .5 mill plys...sound familiar. my tube weighs 7.5 kg,i spared no expense on the aquadere.
i covered every sheet totally with it,but hell it is so rigid and a equivalent carbon fibre tube is only 2.5kg lighter!!
This scope will be used primeraly for astrophotoghraphy,so dave thanks for the inspiration for a great tube design.
i searched hi and low looking at tube design and i cant understand why more people don,t follow suit!!
ONYA DAVE.....CHEERS SKELTY

[davidpretorius]

hmmmmmmmmmmmm, nice zambuto

[DaveGee (Dave Gault)]

Originally Posted by rpsastronomy

and i cant understand why more people don,t follow suit!!

Hi SKELTY,

I completely agree. Cardboard (weetbix) or metal comes a very distant poor second.

I corresponded with a chap from USA who used similar techniques but used 0.8mm thick stuff called 'Door Skin'. It's made for laminating internal house-hold doors and is bonded to the door's internal skeleton. The tube he made was for a 100mm refractor. He never did send me his photos.