12" revisited

[GrahamL]

I originaly built my 12 " dob some years back now and like many atmers
in time found a few things i'd like to revisit.

My ota was always a bit bigger and heavier than it needed to be
I have previously shortened the height , and trimed some off the OD
but it was still a little larger than i would of liked . So recently with a few changes in the pipline for the whole scope , why not build another .

This one is with 12mm marine ply , same focuser , spider,,moonlite connecters, just a little more compact and lighter.

I messed around for ages trying to fashion a fancy carved mounting bracket for my new tak 6x30,then broked it right at the end , I went straight through the side of my telrad this time and it seems to be a much simpler way of doing things :P

next trying to sort a little possible flex ure in my mirror cell springs

or triming down the argo stalk so it can fit sraight in the car still attached to the rocker box

one or the other

[Rod]

I plan something similar. I intend to use the front of a child's scooter as the stalk. It telescopes twice its length and is secured by a clamp. The picture shows what I plan to modify.

Very nice woodwork!

Rod

[GrahamL]

Hey thats a great idea Rod , 'Ill keep it simple for now and cut a couple of inches off the bottom of mine ,being able to slip it down without moving the cables would be handy height wise, wish I'd thought of that earlier.

So hows your child managing there scooter now without handlebars?:P

[Rod]

Ha ha!:)

Luckily it was already broken! Seriously though these scooters are a good source of clamps and bearings for ATM projects. You often see old ones in junk shops.

Rod.

[GrahamL]

The uta came up nice , I gave up trying to wrestle kydex and went with
some thin ply , I think it looks nicer anyways...Thanks to Peter Read
for his help and advice with those little tricks to make things easier

The bracket for the tak finder on the telrad works well

The tiny bit of flexure I believed was due to spring sag in my mirror cell was actually the protostar spider ,the hub needed to be just a litle tighter on the flexible mounting bolt , it was just noticable at low elevation (where I don't really observe anyway) so I never bothered to look into it .

I"ve added 30% more velcro to the mirror cell, and for now probably wont change much down there as it now seems that end is and always was working well.

Some paint in the rocker box and a few nuts and bolts here and there

[GrahamL]

Finally up and running again

new uta
lick of paint here and there
new SPO 12" f5 primary and a new tak finder
some more velcro in the mirror cell
and shortened the argo post so I can fit it in the car assembled to the rocker box.

unfortunately I shortened the uta for some obscure reason and cant
quite get focus now ,so longer poles are in the wind soon

I cobbled an extension of sorts to try it out with my 32 plossl and am very happy .

cheers graham

[alistairsam]

nice work Graham
can the uta be shorter? that could help make it lighter and you could always baffle at the opposite end if required?
cheers

[GrahamL]

Not really its about as small height wise as I would like without loseing the use of baffling thats already there , weight wise its very light , the kineoptics focuser and baby tak finder weigh nothing and will probably still let me lose a conterweight or two when I get the heavier 13 e
in the focuser, though when I lengthen the poles by 40 mm that may change.


graham