Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Cave Astrola 8" Cassegrain/Newtonian

  • Please log in to reply
7 replies to this topic

#1 John Rose

John Rose

    Explorer 1

  • *****
  • topic starter
  • Posts: 65
  • Joined: 02 Jun 2016

Posted 16 September 2020 - 07:27 PM

I believe Cave made such a telescope. But I have not seen a catalog with one in it. I aquired most of one recently. Unfortunately it is missing the cassegrain secondary. I do have hopes that the daughter of the owner will be able to locate it. I presume it is possible that the owner had purchased the parts needed to convert it between the two. 

The mount has the ATROLA name cast in it.  The tube has a Cave Astrola label on it. The mirror has no markings on it.  There is a Pancro label. Has 1110-66 hand written on it. The mirror coating is poor. Unfortunately the newtonian secondary was very dirty. Rinsing did not remove much if any.  I placed it in a dish with water and a small amount of diswashing soap. After a short while I checked and much of the dirt had come off.  And much of the old coating with it! 

After a lot of work, penetrating oil, vinegar and patience the mount has been mostly dismantled. Oh yes, and my neighbors 10 ton hydraulic press. To get the counterweight off the declination shaft. It was really rusted on! Still need to get the lower declination shaft roller bearing out so it can be properly cleand and the hole for mounting the declination setting circle pointer can be drilled out and retapped.

I am hoping to get the cassegrain secondary, and it is in good enough condition to try this scope on Mars.  Even with the poor coating on the primary.

From the Pancro label I suspect the scope might date from 1966. Anyone have any other thoughts on possible age?

 

John Rose


  • L. Regira likes this

#2 photomagica

photomagica

    Ranger 4

  • *****
  • Posts: 312
  • Joined: 23 Jun 2013

Posted 16 September 2020 - 07:52 PM

Try it on Mars even as a Newtonian. You may be pleasantly surprised at the results.

Bill



#3 RalphMeisterTigerMan

RalphMeisterTigerMan

    Apollo

  • *****
  • Posts: 1,430
  • Joined: 01 Nov 2016

Posted 16 September 2020 - 08:20 PM

Back in 1985, Glen Speers of Sky Instruments (Antares) had designed and was selling an 8-inch convertable Newtonian/Cassegrain telescope. I cannot tecall the focal ratios, maybe F/4 - F/15 ish, something like that.

 

To be completely honest it was one of Glen's early attempts at a "mass produced" product and he had never built such an instrument before. It was far from perfect and had it's problems, but, for what it was it wasn't bad. Glen also had to compete with many other manufacturers and they all wanted their piece of the pie for the 1985/86 mass histeria know as the "return of Comet Halley".

 

Considering that Glen is still in business and many other manufacturers from that time have thrown in the towel and locked their doors forever, I'd have to say that maybe his convertable Newtonian/Cassegrain telescope wasn't so bad afterall.

 

Clear skies!

RalphMeisterTigerman


  • Terra Nova likes this

#4 JamesMStephens

JamesMStephens

    Viking 1

  • -----
  • Posts: 896
  • Joined: 25 Jan 2015
  • Loc: Hattiesburg, Mississippi

Posted 16 September 2020 - 08:47 PM

Pictures?



#5 macdonjh

macdonjh

    Fly Me to the Moon

  • *****
  • Posts: 5,957
  • Joined: 06 Mar 2006

Posted 17 September 2020 - 07:38 AM

Parks Optical made similar telescopes (Hybrid Integrated Telescope, 10", 12", 16"), and so did Takahashi (the CN-212).  I have a 10" Parks.  It's fun to be able to change between f/15 and f/4.  If you scroll through this thread you can see some photos from when it was mounted in my observatory photos of the Parks scope are on Page 1).

https://www.cloudyni...t#entry10456579


Edited by macdonjh, 17 September 2020 - 07:40 AM.

  • Bomber Bob likes this

#6 John Rose

John Rose

    Explorer 1

  • *****
  • topic starter
  • Posts: 65
  • Joined: 02 Jun 2016

Posted 17 September 2020 - 06:36 PM

Unfortunately the newtonian secondary is worthless until recoated. It is also custom to the secondary holder.  So a standard 2.1" secondary does not fit. I know I have two of them. need to look further around here to see if I have a secondary holder that fits the spider.  After more than 25 years of Stellafane swap tables I would think I would have some thing to work!  It does not have rotating rings and it sits on a four foot pier. It will take a step ladder to use the newtonian focus.  Iwill try to get some pictures posted.

 

John Rose



#7 macdonjh

macdonjh

    Fly Me to the Moon

  • *****
  • Posts: 5,957
  • Joined: 06 Mar 2006

Posted 17 September 2020 - 08:23 PM

 It will take a step ladder to use the newtonian focus.  Iwill try to get some pictures posted.

 

John Rose

Yeah, same with my 10" Parks.  If I set my mount up low enough to use the Newtonian focuser flat footed, the Cassegrain focuser is near the ground.  If I set it up the other way, the Newtonian focuser is couple step stool steps too high.

 

It's still a cool scope.  Has to be for how heavy it is.

 

Parks 2.JPG


  • Terra Nova and dgreyson like this

#8 photoracer18

photoracer18

    Soyuz

  • *****
  • Posts: 3,550
  • Joined: 02 Sep 2013
  • Loc: Martinsburg, WV

Posted 21 September 2020 - 07:09 PM

I have a Cave 12.5" Cass/Newt, currently dismantled. I do have the Cass secondary although I don't think it was used much. And it needs work (re-aluminizing at a minimum). One of these days I will finish it. I could use it now in the Newtonian mode. Primary in it is not a Cave. It was replaced when it was around 4-6 years old with one made and signed by Dick Brandt when he led the optical shop at OC.


  • tim53 likes this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics