Jump to content


Photo

Using a mount manually as well as goto?

  • Please log in to reply
12 replies to this topic

#1 Mantis707

Mantis707

    Explorer 1

  • -----
  • Posts: 75
  • Joined: 14 Aug 2012

Posted 18 September 2012 - 09:36 PM

Hey folks,

I am trying to make up my mind of which mount to purchase....mostly I seem to be stuck between the G-11 and the CGEM / DX , and the Orion Atlas..... or basically any of the mounts under about 4000$ as that is probably my absolute limit right now for just the mount.

I read somewhere that some of the mounts you can push them around manually (to point at things, find objects, etc..) and then when you get to the object or star in question, you can simply engage the tracking and all will be well.....and in some other cases you cannot do this, as it will interfere with the 'goto' or the tracking.....

So can any of these mounts be 'pushed' manually then easily put back into tracking/goto mode or do you have to do some type of re-alignment if you want to push your scope manually....

Call me old school, but the thought of being tied to a hand controller is odd...

#2 waso29

waso29

    Messenger

  • *****
  • Posts: 498
  • Joined: 12 May 2010
  • Loc: Chi-Town, USA, mother earth

Posted 18 September 2012 - 10:44 PM

Most goto gem mounts will continue to track but will lose alignment once you loosen the drive clutches to move manually.

Maybe instead of goto, consider digital setting circles for "push-to".

I am aware of Orion's SVP gem with intelliscope option allowing one to manually move and still have the encoders aligned for "push-to".
It is only available used since Orion has discontinued the intelliscope option for SVP.

#3 orlyandico

orlyandico

    Fly Me to the Moon

  • *****
  • Posts: 5719
  • Joined: 10 Aug 2009
  • Loc: Singapore

Posted 18 September 2012 - 11:57 PM

If you get a G11 with the optional axis encoders, and you have a Gemini or Gemini 2, I believe you can declutch and move manually without losing alignment.

The Atlas, CGEM, etc. don't have encoder option so this is not possible with them.

Old AP QMD mounts also had axis encoders but had no GoTo. Unless converted with a controller that supports the encoders.

#4 simpleisbetter

simpleisbetter

    Surveyor 1

  • *****
  • Posts: 1848
  • Joined: 18 Apr 2011

Posted 19 September 2012 - 12:41 AM

Can't answer about the G11, but for Celestron, if perform a "Quick Align", all it does is engage and turn on the RA drive, making it a good old fashioned manual mount with dual axis drive controller, no go-to. Or you can do a full alignment for go-to, but no manual unlocking and moving. I believe the Atlas and Synscan software is similar last I looked at one.

Also you can just take the mount out, unlock both axes, and nudge the thing around all night without power for true manual use.

#5 EFT

EFT

    Vendor - Deep Space Products

  • *****
  • Vendors
  • Posts: 2564
  • Joined: 07 May 2007
  • Loc: Phoenix, AZ

Posted 19 September 2012 - 11:29 AM

Such a system would require axis encoders which those three mounts do not have. I'm not familiar with any that do at this point but there may be some. The G11 was able to do this with added encoders but I thought that the limited to the older, non-goto models. Most goto mounts in this range use either steppers with no encoders or servos with encoders on the motor rather than the axis. While these mounts may coninue to track, they will not longer have a goto alignment after manually moving them. If you slew using the hand controller buttons only, they will retain their alignment.

#6 orlyandico

orlyandico

    Fly Me to the Moon

  • *****
  • Posts: 5719
  • Joined: 10 Aug 2009
  • Loc: Singapore

Posted 19 September 2012 - 12:04 PM

The Gemini G53f, AP1600GTO (optional), Planewave Ascension are modern mounts with axis encoders.

#7 michael hester

michael hester

    Viking 1

  • -----
  • Posts: 640
  • Joined: 28 Nov 2008

Posted 19 September 2012 - 01:29 PM

On most of the GOTOs you should be able to Sync on a star if you manually adjust the mount. They also all have a way to engage the tracking motor without calibrating the computer.

#8 mistyridge

mistyridge

    Gemini

  • *****
  • Posts: 3036
  • Joined: 28 Oct 2005
  • Loc: Loomis, CA

Posted 19 September 2012 - 06:38 PM

The G11 has slip clutches on both the RA and DEC so you can push it around and it will continue to track whatever object you aim at. You can star hop without using the goto. Celestron mounts donot have this ability they have positive locks.

#9 SteveInNZ

SteveInNZ

    Sputnik

  • -----
  • Posts: 46
  • Joined: 07 Oct 2007

Posted 19 September 2012 - 06:50 PM

You can star hop a Celestron mount by loosening the clutches and/or using the arrow keys on the hand control. It continues to track and you can still autoguide. It just doesn't know where it is in terms of RA & Dec. Personally, I don't find that to be a problem. In fact, I find it more enjoyable. To each their own.

#10 Lorence

Lorence

    Viking 1

  • -----
  • Posts: 854
  • Joined: 15 Sep 2008

Posted 19 September 2012 - 06:56 PM

Call me old school, but the thought of being tied to a hand controller is odd...


Does having a remote control tie you to your TV? You pick it up, change the channel then set it down until you need it again.

It's no different with a goto controller. Pick an object then set the controller down until you need it again.

The idea is to spend as much time as you can observing not spend as much time as you can searching.

I had an old manual mount before I bought a goto. I found a use for the old mount in my observatory. If I hadn't the old mount would have ended up as scrap metal and firewood.

#11 Startraffic

Startraffic

    Viking 1

  • *****
  • Posts: 802
  • Joined: 12 Feb 2006
  • Loc: Lat. 39.143345, Long. -77.174802

Posted 20 September 2012 - 11:46 AM

Mantis,
I have a G11 & you can push-to & track. However, Once you put Goto on you lose that ability unless you have a set of encoders used with DSCs'. The encoders for Gemini are in the motors, not on the RA/Dec shafts. The optional encoders are installed on the RA/Dec shafts & connected to a port on Gemini. These encoders read the number of "ticks" that each of the axis' make during a move, Slew or push-to. This data is interpolated by the Goto (Gemini) to determine the new position & update the position in the Goto. Sounds weird but it does work.
Finding the original Losmandy encoders is not going to be easy. They haven't been made in at least 5 years.
My G11 has been a series of upgrades from the original Digital Drive System. DDS, Polar Scope, DSCs' & Sky Commander-4, Cassidy Saddle, finally Gemini-2.
I have a set of encoders & they are invaluable during outreach sessions. Folx invariably put their hands on the OTA & move it around, or they'll kick the tripod. I can't track a tripod kick, but I can an OTA push.
All that being said, if you paid $$$ have Goto, why not use it? That is why it's there.

Clear Dark Skies
Startraffic
39.138274 -77.168898

#12 simpleisbetter

simpleisbetter

    Surveyor 1

  • *****
  • Posts: 1848
  • Joined: 18 Apr 2011

Posted 20 September 2012 - 12:09 PM

On most of the GOTOs you should be able to Sync on a star if you manually adjust the mount. They also all have a way to engage the tracking motor without calibrating the computer.


Exactly. Just wish manufacturers said that a little more clearly in their instructions.

#13 Mantis707

Mantis707

    Explorer 1

  • -----
  • Posts: 75
  • Joined: 14 Aug 2012

Posted 20 September 2012 - 05:54 PM

Thanks , all of you, for taking the time to respond to my question. I think I may end up with a G-11, even though they don't make the encoders any longer....I guess If I wanted to I could always put after market encoders on, but it seems like sync'ing to one star isnt such a huge issue.

Thanks again, gents, your advice is VERY much appreciated....CN is just such a great resource...

Mantis






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics