Started about 3 weeks back and have allowed a year to get it done
The ply is a laminate of 2x 12 mm (plantation pine ) I believe.
planning to use moonlite connecters if I can track down some tube to suit the inserts .. have a 2.6 " secondary ..unsure of a primary mirror cell yet or were I'll get the mirror from.. just time .. and money
10 " dob for scale ..patiently waiting for dark and scorpius to rise
Interesting, what are you using in the way of plans?
Excluding the mirror, do you have a rough budget that you think is required for the project?
I purcahased a S/H copy of kriege and berrys book several months back , unfortunately it got lost in the mail somewheres,so this so far is mostly just copied from pics from round the net
Budget ? .. I reckon maybe $700 plus primary ? .. can't see it much cheaper
than that maybe a little if some more used parts show up .
there a small piece of dowl sanded down in each end of the tube
two small stainless screws hold it in place .. the 1/4 x 50 coach bolts
are centred through .. 50 mm is a little long btw 45 would of been better as the secondary has to mount directly below them,, though I think it will still squeeze in there.
Coming along nicely there Graham. I would thought you might of used
treaded rod in those tubes,well that what I've been planning on using.
Still at the end of the day you cage will be lighter for it.
Just for future reference the flower shaped threaded furniture tube closures normally used for mounting the spacing tubes on the top end as shown in Kreige's Truss Dobsonian book, are available from Maumac's in Sydney.
bit cool out your way last night ?.. yeah I thought of some thread bar
to go right through but the extra weight seemed to much for
the little thing your trying to do .. the sanded broom handle bits weigh almost nothing but are a PITA to fiddle with ..the things mark mentions I was aware of but had no idea of what there called or who to source them off .. and theres not many people in a small town to chase after them.
the ply is just a laminate of 2x12 mm ac pine I think .. 24 mm is a fair
thickness but its still light and is very strong .I was always going to paint it black so the nicely finished marine plys would of been a bit of a waste and ..double the price .
FYI rob theres a new specialist aluminium dealler not long opened in ballina
he has everything in stock and a very nice band saw that will cut any angle thickness you might want ,and is fairly cheap those 4 cage spacers were less than $1 each .
thanks for passing on the info mark .. is the company a furniture manufacturer ?.. I so wanted to hold of some of those knowing how simple they make things .
Dam right it was Brrrrr... had the fire going at 4:30am this morning.
Thanks for the info on the new specialist aluminium dealler in Ballina. Do
you know where one can source marine ply over your way? I dont mind
paying extra. I might need someone to cut it for me too.
I'm still a while away from starting my scope, just compiling ideas and
sources for material.
rob hurfords had some great looking sheets of marine ply a while back
$90 I think 2400x1200 x12mm .. lismore would probably have the same
you sure wouldn't need 24 MM of them .
Most large kitchen makers would cut all your straight cuts for a few dollars
on one of those benches you just press a keypad to set the blade at the width you want ..takes no time .
lots of circles and half circles in a scope I've found.. borrow my router if you want cutting circles isn't that hard .. do you have a flat slab or some sort of work area?
thanks Ian.. planning to copy this basic one http://www.ultralightscopes.com/Products.htm
I drew out some weird looking hexagonal shape around this (no idea why )
at first 6 points at 61%.. no edge support fitted as mentioned above
to sit on a drop down tailgate .. but I'm not sure yet and still
looking around ... any suggestions ?
You might want to research the mirror cell issue a little further. There is a program for optimising mirror support locations called PLOP. The link below may be of interest if you haven't already seen it.
In summary about 50% radius is about right for your 6 pt cell support locations.
The Albert Highe mirror cells rely on RTVing the mirror to the supports. Appears to be quite successful. Mag1 Portaball scopes used the same system.
Peter Bobroff recently posted images of a 27 pt all RTV'd mirror cell on IIS. Appears to work quite well. You might want to discuss further with Peter.
Bruce Sayre also uses RTV to attach mirrors to cells.
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