Overhaul of a Cave 8" Lightweight Deluxe
Posted 28 November 2009 - 05:59 PM
Posted 28 November 2009 - 06:06 PM
A beauty and a true classic. Let's see the "after" pictures!
Posted 28 November 2009 - 06:08 PM
Posted 28 November 2009 - 06:14 PM
The 4-vain spider hardware was replaced with stainless allen head fasteners and stainless acorn nuts.
Posted 28 November 2009 - 06:14 PM
Posted 28 November 2009 - 06:18 PM
Posted 28 November 2009 - 06:21 PM
Posted 28 November 2009 - 06:28 PM
Posted 28 November 2009 - 06:32 PM
Posted 28 November 2009 - 06:38 PM
Posted 28 November 2009 - 06:51 PM
I followed Robert E. Cox's November '58 article, "Balancing the Tube of a Reflecting Telescope" to find the best position for the tube weights. On this telescope, there are two sets on either side of the rotating ring. I found that unless only one eyepiece is always used, the angle the tube weights are dynamic and change based on the weight and distance they eyepiece is from the tube. But, the end result is a tube that is balanced quite well and swings any way you want to with just the slightest push. Friction on the RA axis is only enough to keep the clock drive clutch engaged and only enough on the DEC axis to keep the wind from moving it now.
Posted 28 November 2009 - 06:55 PM
Posted 28 November 2009 - 07:11 PM
One of my goals was to reduce the number of tools needed to make adjustments on it in the field. Before, a crescent wrench, set of allen wrenches, large and small standard screwdrivers and a phillips screwdriver were needed to co anything. Now, just a crescent wrench and a set of allen wrenches are all that's needed.
The mirrors are actually in good shape for having never been recoated, however I plan on sending them off soon just because the technology now is a lot better than it was back when Pancro first coated them.
Last night I set it up in front of the house for testing, the DEC circle was set as well as the latitude and it worked great as always.
Something that is kind of disappointing, because this is, after all a Cave, is that almost every hole drilled at the factory seems to have been eyeballed. For example, the three bolt holes for the stand column to the mount base are not 120-degrees apart and can only line up one way. Same thing for the mirror cell to the tube, the clock drive clutch plate and more. Even the cradle is a little off, and has a north - south end and if the tube is put on the cradle 'backwards', it will be about 1 degree off from parallel to the RA axis. But, all this can be adjusted off and doesn't affect the end performance at all.
I live in Arizona and we go camping out in the desert quite often, I can't wait 'till the next trip! Out there, you can see your shadow from the milky way!
Posted 28 November 2009 - 07:26 PM
A beauty, indeed! You did a terrific job. (I'm in the middle of a resto on one of my old 8-inch Newts.) Are the optics pretty good in yours?
Thank you! The optics have always been great. The telescope has always been stored inside and the tube ends plugged to keep dust off. I have only cleaned the mirrors about 10 times in all these years. There are no scratches, but there are some specs of light that come through when holding the mirror up to a bright light. Last night, after dialing in the mount, I tested it on the double cluster and was really pleased with the detail, even though the moon was out.
Posted 29 November 2009 - 07:34 PM
Posted 29 November 2009 - 08:10 PM
Posted 29 November 2009 - 08:15 PM
Nice work - remember not to tighten that turnbuckle too much, or you may crack the cast aluminum drive housing!
Thank you! It is always scary to me working with aluminum, because it's so easy to strip the threads or just break it. For the turnbuckle that mounts to the drive housing, I used a jam nut and flat washers on either side of the housing to spread out the load a little bit and only tightened them enough to be snug and not swivel without a lot of force.
Posted 30 November 2009 - 10:14 PM
It's great to see the original owner put such care and love into a beauty of a scope. I always wanted a Cave, esp. an 8 inch but settled for an RV-6 back then.
Posted 01 December 2009 - 11:25 AM
Posted 02 December 2009 - 02:12 AM
Good job !! Now you can enjoy it for another 40 years.
Thank you! If I live that long, I am sure I will drive my son and daughters nuts by then!
Posted 05 December 2009 - 04:14 PM
Posted 05 December 2009 - 04:28 PM
Did yours have the Dec pointer mounted on the dec housing? And was it a simple L-bracket looking thing?
My mound doesn't seem to have any mounting holes in the castings for a pointer, so I'm wondering where it might have been.
Posted 05 December 2009 - 04:41 PM
The plexiglass pointer is not the original, but the beveled edges are about the same as the original.
Posted 05 December 2009 - 04:44 PM