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

Dovetail for C8 Plus

  • Please log in to reply
9 replies to this topic

#1 DefCon1965

DefCon1965

    Lift Off

  • -----
  • topic starter
  • Posts: 16
  • Joined: 27 Jul 2020

Posted 04 August 2020 - 08:39 AM

I picked up a meticulously maintained C8 Plus for near nothing from an estate sale but I’ve been away from the hobby for a number of years. Optics are downright amazing but the drive motor is dead so I’m thinking I’ll de-fork it and put it on an AVX for visual (and maybe some lunar or planetary imaging) while I build a separate DSO imaging rig. So I need a dovetail for it and not sure which one to get. I had a look on scopestuff but still not sure which one I need.

Can anyone point me at the right one?

Thanks in advance



#2 wrnchhead

wrnchhead

    Vanguard

  • *****
  • Posts: 2,336
  • Joined: 28 Aug 2017
  • Loc: NE Kansas

Posted 04 August 2020 - 08:54 AM

How old is your AVX? I have heard the newer ones have both style of dovetails (but I haven't personally seen this) If it only accepts the narrow style (Vixen, or CG-5, different names for the same thing)

 

https://www.celestro...ar-kit-8-narrow

 

If it will take both, I personally much prefer the wider Losmandy style (or CGE as Celestron calls it) 

 

https://www.celestro...ovetail-bar-cge



#3 DefCon1965

DefCon1965

    Lift Off

  • -----
  • topic starter
  • Posts: 16
  • Joined: 27 Jul 2020

Posted 04 August 2020 - 12:06 PM

I don't have the AVX yet so it'd be new. I didn't even think of Celestron dovetail - thanks for that!



#4 laixiaolue

laixiaolue

    Vostok 1

  • *****
  • Posts: 193
  • Joined: 25 Mar 2017
  • Loc: USA

Posted 04 August 2020 - 01:46 PM

C8 plus OTA needs radius blocks. New Celestron dovetail won't fit the holes.



#5 DefCon1965

DefCon1965

    Lift Off

  • -----
  • topic starter
  • Posts: 16
  • Joined: 27 Jul 2020

Posted 05 August 2020 - 01:36 PM

Thanks for the heads up laixiaolue! Now just need to figure out where to get the radius blocks. I'll have a closer look at the OTA tonight



#6 wrnchhead

wrnchhead

    Vanguard

  • *****
  • Posts: 2,336
  • Joined: 28 Aug 2017
  • Loc: NE Kansas

Posted 05 August 2020 - 01:46 PM

I have not myself put a dovetail on an older C8, but I have read that they do work a few times

 

https://www.cloudyni...ount/?p=6414004

 

 

But I would defer to laix, he may have actual experience. I got a Farpoint vixen dovetail for my 90s Ultima c8, and felt a little burned about the price. The Celestron Losmandy style I got was much more reasonable at $30 and the fit and finish are perfect. The Farpoint one was no better than the one I made myself. The "radius blocks" are little more than a strap of aluminum and a spacer. 

 

Will be curious to know your outcome. 



#7 Matty S

Matty S

    Mariner 2

  • -----
  • Posts: 272
  • Joined: 10 Sep 2017
  • Loc: Hillsboro, Nh

Posted 06 August 2020 - 10:40 AM

I've had the same thought for my C8+. Motor and tripod are iffy at best and the mirror needs a cleaning (coatings may be questionable as well) but adding a rail and using it on the SW-EQ5 seemed a better solution than to try and save the whole lot. Yours sounds in much better condition and would like to see how this pans out for yours.



#8 DefCon1965

DefCon1965

    Lift Off

  • -----
  • topic starter
  • Posts: 16
  • Joined: 27 Jul 2020

Posted 07 August 2020 - 02:02 PM

I checked the layout of the Celestron dovetail and the drawing shows the holes should align perfectly with the existing screws on my OTA so I ordered one. The dovetail (and mount) will be here Monday so I'll report back as to whether it works or not



#9 Terra Nova

Terra Nova

    ISS

  • *****
  • Posts: 23,114
  • Joined: 29 May 2012
  • Loc: Northern Kentucky

Posted 07 August 2020 - 02:38 PM

Thanks for the heads up laixiaolue! Now just need to figure out where to get the radius blocks. I'll have a closer look at the OTA tonight

ADM Accessories



#10 DefCon1965

DefCon1965

    Lift Off

  • -----
  • topic starter
  • Posts: 16
  • Joined: 27 Jul 2020

Posted 11 August 2020 - 07:42 AM

Got the dovetail (and new AVX) yesterday and fitted the dovetail to the OTA and it fits with one issue - the front screw hole on the OTA does not quite line up with the hole in the dovetail. The rear screws are perfect but it seems the front end of the tube is out of line with the rear by about 1/4 inch. I got it on and it's secure but it doesn't match the curvature of the OTA exactly. I've never taken apart one of these OTA's so I'm not sure if the front can be rotated independently of the back (any insight here would be helpful). The other option is to simply take my dremel and elongate the front hole in the dovetail which would make a perfect fit. That is my likely course of action. Downsides?

 

Mount1.jpeg

 

Mount2.jpeg




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