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

Polemaster on a fork mount

  • Please log in to reply
6 replies to this topic

#1 Jeff Struve

Jeff Struve

    Skylab

  • *****
  • Moderators
  • topic starter
  • Posts: 4143
  • Joined: 05 Nov 2010
  • Loc: Iowa, USA

Posted 13 September 2019 - 12:29 PM

Hi all...

 

I did a search for this topic and found 1 back in 2016... no replies at all!

 

Anywho, I am helping one of the local schools set up their new observatory... they have an LX600ACF on a wedge set up in their roll off building and want some help doing a polar align.

 

Anyone have any pics as to how they successfully fastened their Polemaster to this type of beastie?

 

Thanx!

 

Jeff   



#2 Lola Bruce

Lola Bruce

    Apollo

  • *****
  • Posts: 1168
  • Joined: 22 Sep 2014
  • Loc: Southern California

Posted 13 September 2019 - 03:53 PM

Mounted on a wedge a fork is an equatorial mount. As a result the normal polemaster procedure should prevail. My question is first this is a fixed installation? If yes why not do a drift alignment?

 

Bruce



#3 carolinaskies

carolinaskies

    Surveyor 1

  • *****
  • Posts: 1625
  • Joined: 12 Dec 2014
  • Loc: Greenville SC

Posted 13 September 2019 - 06:36 PM

tuthill.jpg

If you look up the old Tuthill finder you'll see the Polemaster will need to be affixed orthagonally off-center like the Tuthill. 

https://www.cloudyni...ope-on-a-wedge/
 

 

In the following thread they postulate mounting the polemaster centered on the dust cover(or make one to fit the polemaster)  

http://www.astronomy...-telescope.html



#4 555aaa

555aaa

    Vendor (Xerxes Scientific)

  • *****
  • Vendors
  • Posts: 1400
  • Joined: 09 Aug 2016
  • Loc: Lynnwood, WA, USA

Posted 15 September 2019 - 04:29 PM

Just clamp it to a fork arm with a c clamp or woodworking clamp. It just has to point north and be rigidly clamped to the ra axis. It does not have to be on axis but it's optical axis should be parallel to the mechanical ra axis. I don't think it has to be perfect.
  • Don W and schmeah like this

#5 schmeah

schmeah

    Fly Me to the Moon

  • *****
  • Posts: 5175
  • Joined: 26 Jul 2005
  • Loc: Morristown, NJ

Posted 20 September 2019 - 07:42 PM

it just needs to move with the RA axis. As long as it’s pointed North you can put it anywhere on the tube.

 

Derek



#6 charlesgeiger

charlesgeiger

    Vostok 1

  • -----
  • Posts: 184
  • Joined: 12 Dec 2011

Posted Yesterday, 02:47 AM

Yes, but it has to be pointing directly north along with the optical axis of your scope.  You will have cone error or other complex errors if it is not perfectly aligned.  If it is off a bit, it will still probably be good for visual.  

Charlie



#7 schmeah

schmeah

    Fly Me to the Moon

  • *****
  • Posts: 5175
  • Joined: 26 Jul 2005
  • Loc: Morristown, NJ

Posted Yesterday, 05:00 AM

Yes, but it has to be pointing directly north along with the optical axis of your scope.  You will have cone error or other complex errors if it is not perfectly aligned.  If it is off a bit, it will still probably be good for visual.  

Charlie

Actually this is not true. It has been explained why many times on CN. See posts # 6, 12 and 16 in this thread. I have confirmed this with my own cheap 59 cent custom adapter. When it is slightly malaligned, it makes no difference.

 

Derek


Edited by schmeah, Yesterday, 06:20 AM.



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