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

GSO 2" Dual Speed Crayford Focuser on the ST80

  • Please log in to reply
87 replies to this topic

#76 kfiscus

kfiscus

    Fly Me to the Moon

  • *****
  • Vendors
  • Posts: 7,128
  • Joined: 09 Jul 2012
  • Loc: Albert Lea, MN, USA

Posted 12 February 2019 - 11:40 PM

Here are some photos of my 2-inch focuser ST80 rig.

Attached Thumbnails

  • 100_2658 35%.jpg
  • 100_2655 35%.jpg
  • 100_2654 35%.jpg

Edited by kfiscus, 12 February 2019 - 11:41 PM.

  • mikerepp likes this

#77 Ryan555_1

Ryan555_1

    Messenger

  • *****
  • Posts: 491
  • Joined: 20 Oct 2017
  • Loc: Phoenix, AZ

Posted 12 February 2019 - 11:48 PM

I note your list includes "ST80 upgraded with 2-speed 2" focuser." That's pretty much where I'm headed with my 80mm (except I'm looking at a single-speed focuser to start). I'm looking at spending in the neighborhood of $500 to do this since I don't have any 2" stuff at all. Is it worth it?


It is worth it! I found that investing in better quality eyepieces accentuates the scope. When I used my Q70s originally with my scope, the outer 50 percent was useless. I still loved it, but it was nothing compared to using a more premium eyepiece. After I bought my ES30 82, the scope really came alive. While there is field curvature due to the fast scope, the whole 6 degree FOV is very usable and pleasing. Gives the best views of the MW!
  • MAT_Blue likes this

#78 MAT_Blue

MAT_Blue

    Sputnik

  • -----
  • Posts: 37
  • Joined: 08 Feb 2019
  • Loc: Saint Louis, Missouri, USA, Earth

Posted 13 February 2019 - 12:48 AM

Budget money for a good 2" diagonal (available used for $75+) and good EPs.  I use all 2" EPs or have dedicated 2-inch adapters on my last two 1.25" EPs.  I strongly feel that the views are worth the money.

I’m looking at "GSO 2" 90-deg 99% Dielectric Mirror Diagonal for Refractor" for $100 from Agena Astro.  There are more expensive one available.  You think this one is a good start?  I realize that's kind of a wide-open question but my setup will be a lot like your ST80.  I'm still researching EPs.



#79 rowdy388

rowdy388

    Skylab

  • *****
  • Posts: 4,020
  • Joined: 09 Apr 2013
  • Loc: Saratoga County, NY

Posted 13 February 2019 - 10:57 AM

I’m looking at "GSO 2" 90-deg 99% Dielectric Mirror Diagonal for Refractor" for $100 from Agena Astro.  There are more expensive one available.  You think this one is a good start?  I realize that's kind of a wide-open question but my setup will be a lot like your ST80.  I'm still researching EPs.

I also did the 2" focuser mod on my ST80 with very good results. Yes, the GSO 2" diagonal is a 

good product and is a good choice. Be aware that the 2" focuser plus star diagonal doubles the 

weight of the original scope. Worth it IMO though as the telescope becomes a low power, wide

field specialist that can do that trick better than any other telescope. It makes a great finder scope.

That's why I usually use mine piggybacked to a larger scope.

 

Edit: I opted for the 2 speed version of the focuser as well. At F/5 it's a nice feature to have.


Edited by rowdy388, 13 February 2019 - 11:01 AM.

  • kfiscus likes this

#80 MAT_Blue

MAT_Blue

    Sputnik

  • -----
  • Posts: 37
  • Joined: 08 Feb 2019
  • Loc: Saint Louis, Missouri, USA, Earth

Posted 13 February 2019 - 05:11 PM

Did any of you guys who put the 2" focuser on an 80mm have to add an extension tube in order to get focus?  In particular, if you used the GSO focuser.  The GSO web site says an extension may be needed.



#81 kfiscus

kfiscus

    Fly Me to the Moon

  • *****
  • Vendors
  • Posts: 7,128
  • Joined: 09 Jul 2012
  • Loc: Albert Lea, MN, USA

Posted 13 February 2019 - 05:43 PM

I didn't need one for any of my EPs.



#82 Agatha

Agatha

    Fly Me to the Moon

  • *****
  • Posts: 5,919
  • Joined: 04 Jun 2012
  • Loc: Wisconsin

Posted 13 February 2019 - 07:04 PM

I have the standard GSO crayford focuser and no problems.  I have only heard of focusing issues when installing the linear bearing version.  The linear bearing version has a shorter drawtube.  



#83 rowdy388

rowdy388

    Skylab

  • *****
  • Posts: 4,020
  • Joined: 09 Apr 2013
  • Loc: Saratoga County, NY

Posted 13 February 2019 - 08:45 PM

Did any of you guys who put the 2" focuser on an 80mm have to add an extension tube in order to get focus?  In particular, if you used the GSO focuser.  The GSO web site says an extension may be needed.

No extension needed. The whole mod was to remove three screws, pull off old focuser, install new

focuser, put three screws loosely back in, look straight through the new focuser without an eyepiece

to make sure I have a clear, round aperture, and finally tighten down the screws. Took as long to type

probably than to do. Very simple. 


  • MAT_Blue likes this

#84 kksmith

kksmith

    Viking 1

  • -----
  • Posts: 584
  • Joined: 08 Mar 2018
  • Loc: Montana

Posted 16 February 2019 - 07:51 AM

I upgraded my ST80 with the Lunt version of the GSO 2 speed focuser which is almost half the price of the GSO branded version. Definitely a sweet upgrade to this venerable little scope.

 

https://luntsolarsys...cuser-3-travel/

 

On the other hand, I recently picked up a Skywatcher 102/F5 with the same Synta focuser, but a 2" version with a 1.25 insert. My first thought was to upgrade it also. But then I decided to strip, relube, and adjust the stock Synta focuser. What a difference in operation this makes. I can get the same fine range of focus the 2 speed gives my ST80. I can literally move it a millimeter at a time. From the factory, the Synta focuser is a weak performer, some call it "junk," but  it has everything in place that allows it to be fine tuned. And while it doesn't look as sophisticated as the GSO, it's definitely cheaper since it is already on the scope.

 

Ken


Edited by kksmith, 16 February 2019 - 07:57 AM.

  • PXR-5 and Ryan555_1 like this

#85 Jim1804

Jim1804

    Ranger 4

  • -----
  • Posts: 364
  • Joined: 26 May 2011
  • Loc: Raleigh-Durham NC, USA

Posted 16 February 2019 - 06:35 PM

I upgraded my ST80 with the Lunt version of the GSO 2 speed focuser which is almost half the price of the GSO branded version. Definitely a sweet upgrade to this venerable little scope.

https://luntsolarsys...cuser-3-travel/

On the other hand, I recently picked up a Skywatcher 102/F5 with the same Synta focuser, but a 2" version with a 1.25 insert. My first thought was to upgrade it also. But then I decided to strip, relube, and adjust the stock Synta focuser. What a difference in operation this makes. I can get the same fine range of focus the 2 speed gives my ST80. I can literally move it a millimeter at a time. From the factory, the Synta focuser is a weak performer, some call it "junk," but it has everything in place that allows it to be fine tuned. And while it doesn't look as sophisticated as the GSO, it's definitely cheaper since it is already on the scope.

Ken


Ken - this looks like a great option! Is it “plug and play” as described by Rowdy above for the GSO?

#86 kksmith

kksmith

    Viking 1

  • -----
  • Posts: 584
  • Joined: 08 Mar 2018
  • Loc: Montana

Posted 17 February 2019 - 04:17 AM

Ken - this looks like a great option! Is it “plug and play” as described by Rowdy above for the GSO?

Yes it is. Undo the screws, remove the stock focuser, replace, and attach the screws. I have the GSO SCT focuser on my C8. Other than mounting style, the GSO and Lunt are identically made with one exception - while the Lunt is rotatable, it doesn't have the knurled locking screw for rotating. You have to loosen grub screws to rotate it. It holds my 2" diagonal and a 2" Meade 50mm Super Plossl (1.4lbs!) just fine.

 

Ken


  • Jim1804 likes this

#87 kksmith

kksmith

    Viking 1

  • -----
  • Posts: 584
  • Joined: 08 Mar 2018
  • Loc: Montana

Posted 17 February 2019 - 05:46 AM

I should add that the Lunt version does not come with a 1.25" adapter - it is a straight 2".  You would still have to buy the adapter if you don't have it plus Lunt charges shipping. I had the one from my GSO SCT focuser so it was not an additional purchase for me. Which was why the Lunt was attractively priced. 

 

Ken



#88 Jim1804

Jim1804

    Ranger 4

  • -----
  • Posts: 364
  • Joined: 26 May 2011
  • Loc: Raleigh-Durham NC, USA

Posted 17 February 2019 - 08:41 AM

I should add that the Lunt version does not come with a 1.25" adapter - it is a straight 2". You would still have to buy the adapter if you don't have it plus Lunt charges shipping. I had the one from my GSO SCT focuser so it was not an additional purchase for me. Which was why the Lunt was attractively priced.

Ken


Good to know - sounds like a great alternative, especially if you already have the adapter. Thanks for pointing this out!


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