|
Some answers
The 13.1" was purchased along with three 18" and two 29" mirror sets from the original Coulter in 1990. I personally went up Mt Wilson to check them out... a long story.
The 13.1" was initially stored under 3M strippable film for a couple of years before being installed in a Dobbie and used overseas in Canada and France, since my return it has been used for visual observing until my accident last year made it difficult to use ( hence the recent sale of the 18" to Gove)
The coating is still original and in usable condition. A good set of optics.
It's still installed in a Sonotube with 9 point mirror cell and 4 vane spider, fitted with a push/pull/ helical 1 1/4" focusser ( for sale also). I've also got a half finished dobbie base/ base board/ machined centre pin which would suit the existing tube (free for pick up)
The Heavy duty mounting was built to set up the 18" in a permanent observatory ( Roof blew off in a gale!!!.. never rebuilt! BTW there's some unused galvanised sheet and 18mm RHS former ( to suit a 6m x 3m run off roof), 4 x 6m 100mm C section rails, 4" sq. post sockets etc also up for grabs.
The mounting weighs about 100Kg + no drives ( Cristian bought the Bartel)
The polar axis is a 10" tube with 2" thrust bearing welded onto the back of a 600mm diameter x 18mm thick disk; on the front of the disk there are two arms 75mm sq. 550mm long and 500mm between. The edge of the disk runs on two hardened rollers 30mm diam x 500mm apart, and the 2" bearing in the tube rests in a hollow thrust shaft. ( to allow wiring thru to the scope) The dec axis is 2" thin wall tubing in 2" HD Plummer blocks. One one side there's a 24" aluminium pully mounted on the dec stub shaft to allow setting up a dec drive. I made up a new centre box from 18mm RHD/18mm angle to suit the 18" mirror cell and truss connections. This could easily be used as is to hold a solid tube up to 18" outside diameter. There's also a set of steel base frames ( 100mm x 50mm channel) which when mounted on the observatory floor allow full setting adjustement of the mounting. Painted royal blue.
As you can imagine this was to be the "ultimate" solid mounting for the next 20 years.
In the forum archives under 444 dobbie sale there are some photos of the mounting and the 333mm dobbie. If you're interested in any of this just drop a PM and let's haggle. There's also two fully machined 18" mirror cells which were designed for an air support system, again open to any/ all offers.
Hope this helps. Unfortunately I won't be using them, so maybe someone can benefit from all the favours that were cashed in to get the material, machining, welding etc done.
|