Jump to content


Photo

After much consideration...

  • Please log in to reply
15 replies to this topic

#1 Doug76

Doug76

    Long Achro Junkie

  • *****
  • Posts: 10839
  • Joined: 05 Dec 2007
  • Loc: Refractor Heaven

Posted 25 February 2010 - 07:21 PM

I sprung for the Atlas over the CGEM. It's longer time on the market, it's reputation for long service without problems, and the fact that a very knowledgeable friend pointed me at it all conspired to make it my choice.
I must admit I would have liked the Celestron software, as I'm already familiar with it, but otherwise I am happy with my choice.

#2 Doug76

Doug76

    Long Achro Junkie

  • *****
  • Posts: 10839
  • Joined: 05 Dec 2007
  • Loc: Refractor Heaven

Posted 25 February 2010 - 07:25 PM

Mods, please move this to Mounts forum, posted it in the wrong place. Sorry.

#3 Yedgy

Yedgy

    Viking 1

  • *****
  • Posts: 700
  • Joined: 22 Jul 2008
  • Loc: Phoenix, AZ, USA

Posted 25 February 2010 - 08:34 PM

Doug, if you're getting into astrophotography, you're going to LOVE EQMOD. That's one of the Atlas' best "features."

Tony

#4 Doug76

Doug76

    Long Achro Junkie

  • *****
  • Posts: 10839
  • Joined: 05 Dec 2007
  • Loc: Refractor Heaven

Posted 25 February 2010 - 10:15 PM

Yep, so I've heard, and another reason I got it.

#5 John J

John J

    Viking 1

  • *****
  • Posts: 603
  • Joined: 05 Nov 2007
  • Loc: South East SD.

Posted 25 February 2010 - 10:25 PM

Here are some reasons I like the Atlas / EQ6.

I recently rebuilt a CG5 AGT for one of our club members. Celestron carries a lot of their engineering practices from one mount to the other. First off they use DC gear head servo motors. DC motors have brushes that will eventually wear out. The gear head inherently has lots of backlash. Gear heads with straight cut gears are noisy. They use the gear head to get the required torque from a relatively small DC motor. The servo system is a closed loop type that is always trying to move the mount to a specified encoder position. If the mount is unbalanced or encounters an obstruction the closed loop system will keep commanding the motors to match the encoder position required. It does this by increasing the amount of current to the motor. This can lead to armature burn out. The encoder is a 200 step per revolution type which equals 1.8 degrees per tic.

The EQ-6 uses stepper motors. Stepper motors have no brushes and have more torque. The motors are direct drive to the worm gear through 2 spur gears. Stepper motors are very quiet. Stepper motors move by advancing the windings and always see the same amount of current no matter what the load. If a stepper motor is over loaded or encounters and obstruction it will stall. The current remains the same and it will continue to advance the windings and the motor will chatter but there will be no damage. Stepper motors are 200 steps per revolution or 1.8 degrees per step. The synscan uses the motor steps as it's encoder. It takes for granted that it told the motor to step and it did. If the motor stalls it will require a re-alignment.

That is a review of the two systems that I am familiar with. It was meant for comparison of the motor drive systems and how they work. I like the EQ-6 system as it uses stepper motors that will practicably last forever and less electronics are involved in the control of the mount position. Less electronics = more reliability.

I own one of the earliest EQ-6 GTs (the old charcoal grey). It has operated flawlessly for well over 5 years now. When the CGEM came on the scene I seriously considered side stepping to that unit. With all the software offerings for the Atlas and EQ-6 type mounts though I just can't justify leaving such of a robust system behind. Not having to worry about motor burnout or brush wear is a plus for the EQ-6. The reduced complexity of the electronics is another plus for the EQ-6. Direct drive to the worm and no gear head is another plus. After market software another plus and on and on.

This is just my opinion but I find that the EQ-6 in the very long run, will be the most robust system of the two due to it's simplicity and rugged construction.

JJ

#6 vinnie

vinnie

    Minister of Misinformation . . . Oh Yes

  • *****
  • Posts: 8716
  • Joined: 05 Jan 2008
  • Loc: Queensland, Australia

Posted 27 February 2010 - 11:00 PM

Yeah good choice Doug.

The EQ6 in a no frills mount to be sure. Its heavy and rather blunt, but its proven its reliability. Mine is one from the first shipment to hit Aus (Mid 2002). No Goto option then, just standard dual axis drives. Later I fitted it with a Goto conversion kit. Mine has really been worked hard with no dramas at all. I should say that about 6 months ago I stripped it down, re-greased and adjusted the worm to crown engagements, but hey after nearly 8 years operation I would put that down to an expected and necessary servicing, much in the same way that any piece of machinery will need some grease or oil and adjustments at some times in its life span.

#7 Phil Cowell

Phil Cowell

    Surveyor 1

  • *****
  • Posts: 1565
  • Joined: 24 May 2007
  • Loc: Southern Tier NY

Posted 28 February 2010 - 02:16 PM

Hi Doug,
Your AT90EDT will work well on the Atlas. I enjoy using mine.
Phil

#8 Darron Spohn

Darron Spohn

    Viking 1

  • *****
  • Posts: 520
  • Joined: 20 Feb 2008
  • Loc: Castle Rock, CO

Posted 28 February 2010 - 10:01 PM

Good choice Doug. I was considering a CGEM until two of our club members had to send theirs back to Celestron for service. One was gone for several months, and this was a new mount. I then joined the CGEM Yahoo Group and read more horror stories about QC issues.

I value reliability above all else.

#9 Avi

Avi

    Viking 1

  • *****
  • Posts: 608
  • Joined: 19 Dec 2009
  • Loc: San Tan Valley, Arizona

Posted 01 March 2010 - 12:30 AM

I've been on the bubble between a CG-5 , or stepping up to a CGEM or Atlas.

The temptation is high to grab a CG-5 since they can be had for around $500. versus almost $1400 for the Atlas.

However, I think I'd rather image with my ST80 on an Atlas,
than an 8" dob on a CG5. I can save up for the 8" dob. ;-)

#10 jrbarnett

jrbarnett

    Eyepiece Hooligan

  • *****
  • Posts: 19727
  • Joined: 28 Feb 2006
  • Loc: Petaluma, CA

Posted 01 March 2010 - 06:39 PM

The Atlas is now $1399 rather than the old price of $1499. Big help, ain't I? :grin:

- Jim

#11 waassaabee

waassaabee

    Fly Me to the Moon

  • *****
  • Posts: 5116
  • Joined: 26 Nov 2007
  • Loc: Central California Coast

Posted 01 March 2010 - 11:58 PM

And I'm seeing the CGEM for $999. (Ouch... wish I'd have waited.)

#12 Starhawk

Starhawk

    Space Ranger

  • *****
  • Posts: 5489
  • Joined: 16 Sep 2008
  • Loc: Tucson, Arizona

Posted 02 March 2010 - 01:02 AM

What's the difference between the Orion EQ-6 and the Skywatcher EQ-6 besides the white paint?

-Rich

#13 JockOnTheRock

JockOnTheRock

    Lift Off

  • -----
  • Posts: 11
  • Joined: 26 Jan 2008
  • Loc: Vancouver, British Columbia

Posted 02 March 2010 - 03:02 AM

The badge is the only other difference.

#14 Starhawk

Starhawk

    Space Ranger

  • *****
  • Posts: 5489
  • Joined: 16 Sep 2008
  • Loc: Tucson, Arizona

Posted 02 March 2010 - 08:42 AM

Looks like availability is the other! They have disappeared from Astronomics and the SkyWatcher site, along with all of their computer guided scopes, SCTs, and the Equinox refractors. Some sort of realignment must be going on at Synta.

-Rich

#15 Darenwh

Darenwh

    Mercury-Atlas

  • -----
  • Posts: 2823
  • Joined: 11 May 2006
  • Loc: Covington, GA

Posted 02 March 2010 - 10:16 AM

And I'm seeing the CGEM for $999. (Ouch... wish I'd have waited.)


Ok, I'll bite... Where did you see that price? Everywhere I look it is at $1399.

#16 attckbvr

attckbvr

    Surveyor 1

  • -----
  • Posts: 1668
  • Joined: 11 Nov 2008
  • Loc: British Columbia, Canada

Posted 02 March 2010 - 10:27 AM

Woodland hills has a demo for $999.00, I phoned yesterday and its still available :)






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics