1965 Cave 10" f/16 Dall-Kirkham OTA
Posted 04 March 2011 - 01:31 PM
I only have one Cave Cass in my mirror registry. It is an 8" from 1974 and has a "conventional" Cave serial number.
Posted 04 March 2011 - 02:01 PM
Posted 05 March 2011 - 02:16 PM
The Unitron focuser also serves as the primary baffle support! Who'da thunk it?
Posted 05 March 2011 - 02:19 PM
Posted 05 March 2011 - 02:21 PM
Posted 05 March 2011 - 02:27 PM
The local high school also has 10" Cave DK that I have been working on. You should replace the baffle with a fixed position one. When you focus the position of the tube moves and either cuts into the light cone coming from the secondary if it is too close to it or if it is to far back, allows sky light to enter into the focal plane and fog the back ground.
Posted 05 March 2011 - 02:29 PM
Posted 05 March 2011 - 02:32 PM
Posted 05 March 2011 - 02:39 PM
Posted 05 March 2011 - 03:40 PM
Posted 05 March 2011 - 03:41 PM
Posted 05 March 2011 - 03:45 PM
Posted 05 March 2011 - 07:06 PM
Posted 05 March 2011 - 07:07 PM
NExt, I put all the components in/on the tube to find the balance point:
Posted 05 March 2011 - 07:13 PM
Here, I've marked the balance point on the saddle plate with an "X", just above the 2nd screw from the left.
Posted 05 March 2011 - 07:16 PM
Okay, going to put it aside for a while so we can go out to dinner early. I'll put the studs in the saddle plate for attaching to the Tak saddle plate (decided to use the thing, rather than buy another Cassidy saddle, since the one for the bigger mount is on the Em-500).
Posted 06 March 2011 - 12:19 AM
Okay, just came from fiddling with it!
Here it is on the NJP. Perfect size mount for this scope!
Posted 06 March 2011 - 12:27 AM
Contrast was pretty good - though I suppose such a huge secondary (30%) helps keep stray light out of the primary baffle.
Posted 06 March 2011 - 07:21 AM
Please let me know the projects you can't get to! You have some GREAT projects!
Anyway, I just popped in while getting some coffee on an observing session, (casual Messier Marathon)
On a side note on one of your earlier posts on this thread on the primary's and secondary's coating. Metal likes to be thin in vacuum deposition, this actually gives a higher reflectance. Even with a dielectric protected overcoat the transmission would be nil but if you hold a 60 watt or even a bright flashlight behind an optical mirror you could detect the light source. Did I mention this isn't intuitive?
Thicker coatings are deposited most of the time so customers don't complain and want a refund or a do over.
Lastly, Happy Birthday!
Posted 06 March 2011 - 10:58 AM
Quote from the Cave catalog for this scope:
"Designed and manufactured for the observer desiring maximum resolution and definition for planetary and lunar observing".
Specs show 2.9" secondary and over 4000mm focal length.
Is it possible the extremely high focal ratio f16 can cancel out and overcome the 30% CO?
Just wondering why you didn't need CPR after 1st light, collimation is critical with this design? and probably getting the secondary exactly on axis.