Thanks Col,
I am going to take a little break from it tomorrow. Heading off to Parkes tonight for the Central West AstroFest. I am pleased to have the bulky stuff almost finished. I am going to get it all set up and test drive it before pulling it all apart again for the final sanding staining painting and polishing etc.
I have an appreciation for your work as I have just assembled my mirror box inside the rocker using construction ply.
Have taken note that your rocker box end boards, particularly the high one finishes snug against the mirror box at zenith, thus stopping any movement past Zenith. I made my rocker a little long and should shorten it with final version. Its all a bit trial and error at this stage, but fun!
Hello Neil,
The Mirror box actually has 4mm clearance on the sides and against the front, once painted there will be 4mm felt pads glued as gliders to stop excess movement.
Yes, M8 'T' nuts recessed so they end up flush (actually 0.5mm below the surface) you can use either zinc plated or stainless steel ones. The secondary struts have threaded inserts. I got mine from Peter at SDM but they are available from places like Specialty Fasteners. Lookie here: https://www.essentracomponents.com.au and search for ' spring threaded insert '
The truss poles will have a plate joining each pair of poles and a bicycle seat post quick release clamp as the fastener.
The wheelie handles will be attached to the rocker box with M10 T nuts similarly recessed into the plywood.
Back in the holding pattern, waiting for Mr Postman to bring me more pieces ....
In the meantime I have sorted out the linear bearings for the mirror sling
The 10mm linear bearing just happens to have a 19mm OD so a short length of 19mm irrigation hose was cut and slid over the bearing and is held in place by two s/s hose clips ...... the 3mm 7x19 s/s wire rope will sit between the clips so that it cannot slip off the bearing. Should make for a very smooth movement and thus the mirror will always be supported at the centre of gravity (in my case 19.25mm from the back of the mirror.
Also scored a 1800x1200 sheet of postforming laminate in a nice texture for $40. The laminate is just less than 0.8 mm thick and after I sand the back a little to get it down to about 0.65mm, it will make a perfect light baffle for the UTA......
Another little item out of the way is a 12mm thick spacer for the focuser to prevent the draw tube intruding into the light path, cut from marine ply and sanded down to the right thickness ... fiddly bits
Next on the agenda are the pole clamps, "Cut to Size Plastics" in Sydney are supplying the black acetal block cut to my specs for $6.05 cents each !!!! How good is that !!!!
Well, my new mirror sling from Howie Glatter arrived yesterday. I was going to PM you to ask if the old one would be of any use to you, but you seem to have that base more than adequately covered!
Last edited by rrussell1962; 29-07-2015 at 06:59 PM.
Reason: Abuse of grammar.
Well, my new mirror sling from Howie Glatter arrived yesterday. I was going to PM you to ask if the old one would be of any use to you, but you seem to have that base more than adequately covered!
Thanks Richard, yes all the bits for the cell/sling/tailgate are now ready.
My Delrin blocks arrived for the pole clamps, just waiting for a TCT Forstner bit from Carbatec, then the mirror box will be ready for finishing.
Still waiting for some parts for the upper pole clamps and the pivot kit/encoders/DTC.
Lower truss pole clamps cut & drilled today (still need to cut the split)
Delrin 80mm x 52mm x 46mm
The block will be mounted horizontally for aesthetic reasons so the 32mm hole was drilled at an angle of 7.5º from vertical. This stuff is hard as ..... but the TCT Forstner bit did extremely well.
Job worth doing is worth overdoing !!!! Progressing ever so slowly as I am having to do the project while minding my granddaughter. When she sleeps I get out for 30 minutes painting etc.
Camera going in for service so no pics for a week or so .....
Still waiting for the postie to bring some parts and it is too cold here to varnish anything so yesterday I started on the ground board (can't drill the pivot hole till the pivot arrives ...)
Oil based gloss black to keep moisture out .......
then the obsessiveness kicked in again so the base of the board got painted gold with an overspray of black flecks
That made the red wheel rims look out of place so they had to be dismantled, sanded, etch primed and then painted gold with PPG Gold Dust.
Also found time to install the Noctua NF-B9 92mm fan which pumps out 64.5 cubic metres per hour or 38cfm and is nearly silent. Noctua fans also come with a 6yr warranty !!
There are Dobs, that look like they have been made out of recycled cardboard boxes and cement pylon paper tubes, and then there is the Kunama Dob... a class in it's own right.
Only thing, not sure the gold fleck idea works. Solid gold, yes, but the fleck looks a bit off IMHO.
I think I have OCD 
... perfection at it's finest ..!!
