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

Astro-Tech 16" RCT V2 engineering drawing

This topic has been archived. This means that you cannot reply to this topic.
7 replies to this topic

#1 frebie

frebie

    Chief assistant to the assistant chief

  • -----
  • In Memoriam
  • topic starter
  • Posts: 1,684
  • Joined: 29 Apr 2008

Posted 08 July 2015 - 11:19 AM

For those of you interested in how the current Version 2 of the AT16RCT goes together, the attached drawing of the new rear cell design should be of interest. 

 

The focuser attachment collar bolts rigidly onto the scope back plate. The mirror and baffle tube are attached to the separate 18-point floatation mirror cell, which is connected to the back plate via springs and six push/pull screws for collimation. The focuser attachment collar is no longer attached directly to the mirror/baffle tube as a single assembly. This allows the focuser to be collimated separately from the primary mirror (if needed) by using an optional focuser collimating ring between the focuser and the focuser attachment collar.

 

All of the current Astro-Tech truss-tube RCs will be using the same rear cell design.

 

In addition, all of the truss-tube RCs now come with primary and secondary mirror covers and a mounting shoe for an optional red dot finder.

Attached Thumbnails

  • at16rct-ver2.jpg


#2 Cosmic Visionary

Cosmic Visionary

    Lift Off

  • *****
  • Posts: 2
  • Joined: 12 Apr 2011

Posted 11 July 2015 - 06:56 PM

Any possibility of AT upscaling from their 20" model and offering a 24 " model to compete with Plane-Wave and the like ?

 

Ron Barnell



#3 Astronomics

Astronomics

    Vendor: Astronomics

  • *****
  • Administrators
  • Posts: 6,641
  • Joined: 07 Jun 2004

Posted 13 July 2015 - 09:26 AM

Lets get the 20" into production and then we will see.  The production capability is there however.



#4 mclewis1

mclewis1

    Thread Killer

  • *****
  • Posts: 20,611
  • Joined: 25 Feb 2006

Posted 13 July 2015 - 12:05 PM

Mike,

 

Thinking back a few years (say before the RCs were introduced), could you ever have imagined Astronomics having a serious discussion about carrying a 24" truss tube RC scope?



#5 scooper

scooper

    Lift Off

  • -----
  • Posts: 1
  • Joined: 08 Jul 2015

Posted 16 July 2015 - 01:30 PM

AttachedRZ_RZ_HORSEHEAD16.JPG is a first light test with the AT 16" RC.
This was when I was experimenting with the spacing of the AP 27TVPH reducer/flattener.
It is only 4 subs (30 min. each) so no flats or anything. The data looked too good to throw away even though the spacing and collimation needed more tweaking so I ran it through PixInsight.
    Steve
http://www.pbase.com/image/160623432



#6 Astronomics

Astronomics

    Vendor: Astronomics

  • *****
  • Administrators
  • Posts: 6,641
  • Joined: 07 Jun 2004

Posted 16 July 2015 - 03:45 PM

Mike,

 

Thinking back a few years (say before the RCs were introduced), could you ever have imagined Astronomics having a serious discussion about carrying a 24" truss tube RC scope?

Nope.  It has been a really interesting ride.  Hopefully it will continue to grow.



#7 Astropetev

Astropetev

    Lift Off

  • -----
  • Posts: 9
  • Joined: 30 Mar 2009

Posted 03 October 2015 - 03:42 PM

I have the 10" truss version from Teleskop Service in Germany, it also has the focuser mounted on the backplate to help accurate collimation.  I can just about lift it onto my Observatory mount single handed - reckon I'd need a mini crane to install a 20", never mind 24" ;-)

 

Very pleased with my 10" and not likely to go larger - the UK skies are hardly ever good enough to make use of the increased resolution and focal length, indeed I 'downsized' from a 12" Meade ACF!  Like my 10" does the 16" AT version originate with GuanSheng Optical in Taiwan?

 

Cheers,

 

Peter

 

http://www.madpc.co.uk/~peterv
Approx. 55ºN, 2ºW  (Northumberland, UK)

Attached Thumbnails

  • Shroud.jpg


#8 rockenrock

rockenrock

    Explorer 1

  • -----
  • Posts: 59
  • Joined: 11 Jun 2012

Posted 06 October 2015 - 11:09 AM

I have GSO 10RC, and hang STT8300 + self guiding filter wheel + AO8T. Quite a bit of weight. 

I found the same flex mentioned above as being corrected with the truss tube focuser/image train directly to the back plate. To check the flex I used focuser + Howie Glatter laser. Pulling down on body of focuser approximately the weight of my image train, the laser dot moved from inside to almost outside the secondary donut. When pull down same amount on draw tube it definitely moved outside the donut. I think collimation will be changing with different OTA pointing positions.

 

To correct this:

1. I designed and built an isolator part the bolts directly to the back plate and goes around (1/16" clearance all around) the original tube the focuser screws to. The isolator has same threads, so extensions/focuser attach nicely.

2. The GSO 3.3" focuser is nice for visual or DSLR AP, but  not up to the task I need. So I replaced it with Moonlite CSL focuser with 68mm threaded connection to STL thread of AO8T. Now everything rock steady... Same tests as above (Glatter install to focuser), and the laser dot stays inside the donut. Maybe moves a slight amount when pull down on draw tube. Push on the image train, and it feels rock steady.

 

Non-star collimation:

Now the system pieces can be independently collimated. 

1. Use Glatter in 2" adapter in Moonlite focuser and rotate Glatter only to check if it is collimated (was perfect)

2. Rotate focuser (it has collimatable rotation rings) to different positions and adjust the focuser collimation so the laser dot is not drawing it's own donut on the secondary.

3. Shim the new isolator part such that the laser dot is in the middle of secondary. (Now the axis of focuser is pointing directly at donut of secondary).

4. Check step 2 and then 3 again. 

At this point I can confidently rotate the focuser, and everthing stays aligned.

5. Adjust secondary so laser reflects directly back on center of the Glatter. (Use your trusty LED flashlight to light up the end of the Glatter and see the reflected beam better).

6. Rough check primary collimation with Glatter concentric ring  hologram.

7. Star test using eyepiece (if doing visual), or add image train and star test collimate secondary and primary. (Deep Sky method)

 

I am waiting to do Step 7, but that nasty rain from 2 days ago hurricane (typhoon over here) keeps coming and coming.

 

Roger




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