Jump to content


Photo

iOptron ZEQ25GT Payload Test (AT10RC)

  • Please log in to reply
15 replies to this topic

#1 Astronewb

Astronewb

    Apollo

  • *****
  • Posts: 1294
  • Joined: 19 Sep 2011
  • Loc: Connecticut

Posted 04 March 2013 - 01:55 PM

Some users have asked about slews at the mount's rated capacity, so I rigged up the AT10RC on the mount to test it at 32 pounds.

Posted Image
AT10RC_ZEQ25GT by Astronewb2011, on Flickr

The little 10 pound mount didn't even break a sweat..here's a link to the YouTube video:

http://www.youtube.c...h?v=_cIOTROXEpQ

No, don't even think about putting this much weight on the ZEQ25GT in normal use...this is just a test....!

Cheers all,

Paul

#2 psandelle

psandelle

    Viking 1

  • -----
  • Posts: 661
  • Joined: 18 Jun 2008
  • Loc: Los Angeles

Posted 04 March 2013 - 02:36 PM

Paul - great stuff! Totally enjoying all your videos. I have my iEQ30...so won't spring for this, but when the replacement for the 45 comes out, that's probably what I'll go for (with encoders).

Keep 'em comin'!

Paul

#3 Ricky

Ricky

    Mercury-Atlas

  • *****
  • Posts: 2730
  • Joined: 09 Sep 2003
  • Loc: Nor Cal

Posted 04 March 2013 - 02:58 PM

Nice!!! I wonder if ioptron will offer a pier/pedestal option for this mount...

#4 zawijava

zawijava

    Viking 1

  • *****
  • Posts: 920
  • Joined: 06 Oct 2007
  • Loc: Wells, Maine 04090

Posted 04 March 2013 - 04:25 PM

Enjoying your videos Paul, thanks! Does this mount use belts in the drive system? If so, can you or others comment on the benefits and drawbacks of belt drives please :question:

thanks! -Tim

#5 Astronewb

Astronewb

    Apollo

  • *****
  • Posts: 1294
  • Joined: 19 Sep 2011
  • Loc: Connecticut

Posted 04 March 2013 - 04:36 PM

Enjoying your videos Paul, thanks! Does this mount use belts in the drive system? If so, can you or others comment on the benefits and drawbacks of belt drives please :question:thanks! -Tim


Hi Tim,

This mount uses cogged belt drives on each axis. In fact, the belt passes thru a reduced section of the mount casting, between pulleys, which serves to act as a belt tensioner of sorts.

The motors are planetary geared reduction DC servo motors. and as you can see in the video..they're pretty potent.

There is not a lot of excessive distance between the two cogged pullys, so the belt almost has to be forced over the pully to seat it...very nice setup.

One advantage to a cogged belt drive is no belt slippage, and a reduced drive harmonic due to the damping characteristics of the belt itself. A direct geared drive would have the dis-advantage of being susceptible to dirt, which would affect periodic error...?

Perhaps some engineering types can comment further?

Thanks for the nice comments,

Paul

#6 Astronewb

Astronewb

    Apollo

  • *****
  • Posts: 1294
  • Joined: 19 Sep 2011
  • Loc: Connecticut

Posted 04 March 2013 - 04:48 PM

Thanks Paul and Ricky.

@ Paul...if a "Z-Balanced" mount comes out, the same or similar capacity as the iEQ45 , with precision encoders...I'll be all over it like stink on you know what.

@ Ricky...there is an optional 2" tripod that will be available, but I haven't heard anything about a pier yet...though with the adjustable counterweight..a pier is just 'nice' to have instead of 'must' have for low latitude users.

And for the users in Alaska, at 62 degrees lat..this mount will go to 61.7 degrees max, measured with an inclinometer..so you might have to look elsewhere, or move where it's warmer...:) (Or lower two tripod legs for the extra few degrees)

Clear skies,

Paul

#7 Ricky

Ricky

    Mercury-Atlas

  • *****
  • Posts: 2730
  • Joined: 09 Sep 2003
  • Loc: Nor Cal

Posted 04 March 2013 - 05:30 PM

Thanks Paul,
If I decide to pu this mount I may just have a 4" adapter plate machined to fit on my ped30 pier...

#8 tjugo

tjugo

    Viking 1

  • -----
  • Posts: 966
  • Joined: 06 Nov 2007

Posted 04 March 2013 - 07:28 PM

Paul et al,

What's the difference (in performance) between this mount and the iEQ30? Feature and capacity-wise they look pretty close, but this mount is almos 40% cheaper.

I will pull the trigger soon on a new mount small mount, my candidates were:

-- Orion Sirius
-- Celestron AVX

And now I am interested in this new mount...

Cheers,

Jose

#9 Astronewb

Astronewb

    Apollo

  • *****
  • Posts: 1294
  • Joined: 19 Sep 2011
  • Loc: Connecticut

Posted 04 March 2013 - 11:05 PM

What's the difference (in performance) between this mount and the iEQ30? Feature and capacity-wise they look pretty close, but this mount is almos 40% cheaper.


Right Jose, they are close in performance. But the iEQ30 is the classic German EQ type..no real fulcrum point, just a couple of latitude locks placed anywhere it's convenient.

The Z Balanced Chinese Equatorial mount has a centrally located fulcrum pin, which allows for better weight transfer and balance..especially due to the 'Z' design.

And I presume the cost is driven down by the smaller casting needed for the mount, and a sharing of previously proven components whose initial R&D costs have been largely absorbed. Makes me wonder why Apple and MS prices continue to rise..? :)

The ZEQ25GT mechanically and from a design standpoint is excellent. The software routines I have still not fully explored due to lack of clear nights. I know the tracking and go-to's are spot on. Now to see how it images....

Best,

Paul

#10 timmbottoni

timmbottoni

    Surveyor 1

  • -----
  • Posts: 1727
  • Joined: 25 Aug 2005
  • Loc: W Chicago suburbs, IL USA

Posted 04 March 2013 - 11:18 PM

Wow - that's cool. I'm really looking at the iEQ45 for getting started with DSLR AP - thanks for your posts and videos

Timm

#11 EFT

EFT

    Vendor - Deep Space Products

  • *****
  • Vendors
  • Posts: 2545
  • Joined: 07 May 2007
  • Loc: Phoenix, AZ

Posted 05 March 2013 - 10:11 AM

One advantage to a cogged belt drive is no belt slippage, and a reduced drive harmonic due to the damping characteristics of the belt itself. A direct geared drive would have the dis-advantage of being susceptible to dirt, which would affect periodic error...?



A toothed belt drive is really not much different than a geared drive. It is suseptable to PE, dirt, etc. just like a geared drive. It may in fact be more difficult to keep tight controls on the quality of the belt used (an likely made by a different company) than on gears. They are really just different means to the same end.

#12 Jaime Riviere

Jaime Riviere

    Sputnik

  • -----
  • Posts: 36
  • Joined: 07 May 2009
  • Loc: Salamanca, Spain

Posted 09 March 2013 - 02:35 PM

Thanks for the videos, Paul. They are really informative ;) I am also thinking on this mount, although it is not the best moment pocket-wise...

#13 korborh

korborh

    Viking 1

  • *****
  • Posts: 802
  • Joined: 29 Jan 2011
  • Loc: Arizona

Posted 09 March 2013 - 04:38 PM

One advantage to a cogged belt drive is no belt slippage, and a reduced drive harmonic due to the damping characteristics of the belt itself. A direct geared drive would have the dis-advantage of being susceptible to dirt, which would affect periodic error...?



A toothed belt drive is really not much different than a geared drive. It is suseptable to PE, dirt, etc. just like a geared drive. It may in fact be more difficult to keep tight controls on the quality of the belt used (an likely made by a different company) than on gears. They are really just different means to the same end.


Right, AP mounts use many gears in its gearbox and have ultra-low PE.
Gears have advantages as they wont be susceptible to stretching/slippage, are more robust, longer life and provide more torque. I can imagine the precision ones costing much more than belts.

#14 Astronewb

Astronewb

    Apollo

  • *****
  • Posts: 1294
  • Joined: 19 Sep 2011
  • Loc: Connecticut

Posted 10 March 2013 - 12:28 AM

Gears have advantages as they wont be susceptible to stretching/slippage, are more robust, longer life and provide more torquert


True enough. But cogged tooth belts have 'zero' slippage. Every modern racing engine and sports car mfg uses mainly cogged tooth timing belts, subject to rpm's of 10,000 rpm per minute and up...with no issues.

How much torque is a cogged belt subject to driving up to 32 valves, and torsion springs at 8000-10,000 rpm?

I don't think a cogged belt on a servo motor running at sidereal speed is going to have any problem whatsoever. Just saying...:)

Cheers,

Paul

#15 herrointment

herrointment

    Aurora

  • *****
  • Posts: 4608
  • Joined: 12 Mar 2011
  • Loc: North of Hwy. 64

Posted 10 March 2013 - 02:29 AM

I once lusted for a comely LX80 but she was an illusion.

This siren sings a rapturous tune, I do reckon!.

#16 Senator48

Senator48

    Lift Off

  • -----
  • Posts: 15
  • Joined: 12 Mar 2012
  • Loc: New Jersey

Posted 11 March 2013 - 02:07 PM

Great video! Thanks for taking the time - and risk to you RC - to do this mount test. Have to add this to my short list of potential mounts.






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics