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Trever
Post Laureate


Reged: 08/18/03
Posts: 3144
Loc: North Alabama
Alt-Az mount for a large refractor?
      #3074924 - 04/29/09 12:53 PM

Does anyone know of an Alt-Az mount of some kind that is available for large refractors such as my Meade 152ed refractor? I was thinking of getting another CGEM with an extender in the near future but I wanted to check first.

I will say that these scopes are bigger than the standard F/8's offered by Synta so it would have to he hefty.

--------------------
Trever

------------------------------------------
Celestron C 9.25 on ASGT mount
Zhumell 12 inch Dobsonian Reflector
Vixen A70LF 70mm Refractor OTA
Nikon 8x42 Trailblazer Binos
Stellarvue M1 mount
------------------------------------------



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zjc26138
Loved By All


Reged: 02/24/05
Posts: 6961
Loc: Mingo Junction, Ohio
Re: Alt-Az mount for a large refractor? new [Re: Trever]
      #3074963 - 04/29/09 01:09 PM

I think a DM-6 will work.
here

or a APM Max-load Alt-Az mount.
here

--------------------
TMB130 SS (Currently out of service. )
Celestron Edge 8"
iEQ45m
Meade 102ED
Stellarvue 80/9D

9/11- Never Forget.


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Trever
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Reged: 08/18/03
Posts: 3144
Loc: North Alabama
Re: Alt-Az mount for a large refractor? new [Re: zjc26138]
      #3075151 - 04/29/09 02:26 PM

Good suggestions. I will check them out.

--------------------
Trever

------------------------------------------
Celestron C 9.25 on ASGT mount
Zhumell 12 inch Dobsonian Reflector
Vixen A70LF 70mm Refractor OTA
Nikon 8x42 Trailblazer Binos
Stellarvue M1 mount
------------------------------------------



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zjc26138
Loved By All


Reged: 02/24/05
Posts: 6961
Loc: Mingo Junction, Ohio
Re: Alt-Az mount for a large refractor? new [Re: Trever]
      #3075158 - 04/29/09 02:30 PM

I had a chance to play around with the Max mount at NEAF. Boy is it a beast, as well as a joy to use. Marcus(owner of apm) had a Meade 127 Triplet on it and on the other side a 8in f/8 Archo. I figure about 25 pounds for the Meade and close to 45 or more pounds for the Archo. Thats close to 70 pounds. I would recken that the mount probably could easily hold 50 or more pounds on one side, given you had a big enough tripod.

*I just remembered. I played around with a DM-6 also. It had a TEC140 on it and the motions were smooth as silk.

Edited by zjc26138 (04/29/09 02:31 PM)


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Herenomore
Carpal Tunnel


Reged: 11/29/04
Posts: 1833
Re: Alt-Az mount for a large refractor? new [Re: Trever]
      #3075345 - 04/29/09 04:03 PM

Trever:

The DiscMounts DM-6 will easily handle loads heavier than your Meade 152. For example, some of the scopes pictured here:

http://discmounts.com/gallerys/CUSTOMER/cust_gallery.htm

here:

http://discmounts.com/gallerys/CUSTOMER/published/galleryframe.html

and here:

http://www.discmounts.com/gallery3/DMG3_p1.html

Tom


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Trever
Post Laureate


Reged: 08/18/03
Posts: 3144
Loc: North Alabama
Re: Alt-Az mount for a large refractor? new [Re: Herenomore]
      #3075488 - 04/29/09 05:15 PM

Ive been looking through their site. Seems that is the way to go. Looks like it will also support a sky commander.

Seems to be a good quality mount.

--------------------
Trever

------------------------------------------
Celestron C 9.25 on ASGT mount
Zhumell 12 inch Dobsonian Reflector
Vixen A70LF 70mm Refractor OTA
Nikon 8x42 Trailblazer Binos
Stellarvue M1 mount
------------------------------------------



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zjc26138
Loved By All


Reged: 02/24/05
Posts: 6961
Loc: Mingo Junction, Ohio
Re: Alt-Az mount for a large refractor? new [Re: Trever]
      #3075491 - 04/29/09 05:17 PM

Quote:

Ive been looking through their site. Seems that is the way to go. Looks like it will also support a sky commander.

Seems to be a good quality mount.




There very nice, both the DM-4 and the DM-6. I got the feel for them the Friday of Neaf, when there weren't people around. I think you'll be very happy if you go with the DM-6.

--------------------
TMB130 SS (Currently out of service. )
Celestron Edge 8"
iEQ45m
Meade 102ED
Stellarvue 80/9D

9/11- Never Forget.


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Herenomore
Carpal Tunnel


Reged: 11/29/04
Posts: 1833
Re: Alt-Az mount for a large refractor? new [Re: Trever]
      #3075500 - 04/29/09 05:24 PM

Trever:

Although it can be used without them, Tom Peters designed the mount to be used with DSC's. Tom Trusock reviewed the DM-6 here when it debuted in '03:

http://www.cloudynights.com/item.php?item_id=611

(Not pictured in the review is the DiscMounts tray which is now available)

Tom


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JumboFlex
sage


Reged: 01/20/09
Posts: 373
Re: Alt-Az mount for a large refractor? new [Re: Herenomore]
      #3075601 - 04/29/09 06:18 PM

Last time I checked the DMs were considered the best altaz mounts around, you pay for that though, but numerous people feel that its worth it.

The DM6 can handle some big scopes.

--------------------
JF

Double undercuts... for safety!


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ad701xx
Pooh-Bah


Reged: 11/22/03
Posts: 1133
Loc: Oregon, USA
Re: Alt-Az mount for a large refractor? new [Re: JumboFlex]
      #3075692 - 04/29/09 07:11 PM Attachment (91 downloads)

The Giro III does great with my TEC 140 which weighs somewhere around 27 lbs all up.

Attachment

--------------------
Dave

2 scopes with 3 pieces of glass in the front, one has a little oil in it.
4 scopes with shiny glass at the bottom.
2 Cats
A few eyepieces.




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maknewtnut
Member


Reged: 10/08/06
Posts: 1333
Re: Alt-Az mount for a large refractor? new [Re: ad701xx]
      #3075727 - 04/29/09 07:28 PM

As others have mentioned, you may not need a monster a/a mount, just a good one. In the scheme of things, the Meade ED's aren't too hefty. The keys are not only a good mount, but a great tripod. This is often overlooked in the effort to remain as portable as possible. That can still be accomplished, but scrimping on the tripod, especially when used to support a scope with significant moment arm, will detract from the experience.

--------------------
Mark


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Trever
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Reged: 08/18/03
Posts: 3144
Loc: North Alabama
Re: Alt-Az mount for a large refractor? new [Re: maknewtnut]
      #3075978 - 04/29/09 10:11 PM

Would the ash tripod that they offer for the DM6 be sufficient or should a G11 tripod be recommended?

--------------------
Trever

------------------------------------------
Celestron C 9.25 on ASGT mount
Zhumell 12 inch Dobsonian Reflector
Vixen A70LF 70mm Refractor OTA
Nikon 8x42 Trailblazer Binos
Stellarvue M1 mount
------------------------------------------



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Jim7728
Postmaster


Reged: 04/10/05
Posts: 7284
Loc: Stoop Landing Observatory, NYC
Re: Alt-Az mount for a large refractor? new [Re: Trever]
      #3076091 - 04/29/09 11:09 PM

That G-11 tripod with riser column would be my choice for the 152ED.

http://discmounts.com/gallerys/CUSTOMER/images/discmount_cust89.jpg

--------------------
<Jim>15x70-Ultra~TV-85/SM-60~MN-66
Unistar Deluxe~Unimount Light~DM-6


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drshr
scholastic sledgehammer


Reged: 06/09/08
Posts: 959
Loc: Darwin, Australia
Re: Alt-Az mount for a large refractor? new [Re: Jim7728]
      #3076142 - 04/29/09 11:31 PM

I use the Orion AZ, also known as the skytee here in OZ. Rated at 50lb I thought I would test it out with my 8" and 6". The mount has handled them with ease. A pier would help.
2 scope setup also has its advantages.

--------------------

14" F5 DOB
APM 8" F6 Achromat
ISTAR 152mm F10 Perseus
APM 105mm F6.2 CF APO
Synta 150mm F5
Synta 120mm F8.8
Garrett 28x110
Oberwerk 25x100
Zeiss 20x60S



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darylf96
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Reged: 08/28/04
Posts: 1432
Loc: Danville, California
Re: Alt-Az mount for a large refractor? new [Re: Trever]
      #3076256 - 04/30/09 12:35 AM

If you want a great mount for visual observing, the DM-6 with Sky Commander DSCs on a HD tripod with an extension would be super. I have the DM-6 with the DSC unit on a HD Meade tripod (with leg spreader) and a Losmandy extension, and it handles my 6 inch refractor like a dream. It also handles my 10 inch SCT with ease.

Daryl

--------------------
Intes Micro MN66 - Meade 10" SCT
Orion EON 120mm ED f7.5 Apo
Skywatcher 150mm f8 Achro
G-11, CG5A-GT Mounts
DM-6 With Sky Commander DSC
Astro-Tech AT80 Refractor f6.9 APO
Stellarvue 20x85 binos - Unimount
Kunming United Optics 7x50 binocs
Canon Rebel XT, Canon 20D, Canon 7D, Canon SXi
SBIG ST-8XE




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Herenomore
Carpal Tunnel


Reged: 11/29/04
Posts: 1833
Re: Alt-Az mount for a large refractor? new [Re: Trever]
      #3076701 - 04/30/09 10:15 AM

Quote:

Would the ash tripod that they offer for the DM6 be sufficient or should a G11 tripod be recommended?



Trever:

DM's ash tripod is furniture quality and very solid but without knowing the weight/length of the 152ed, I can't say whether it would be sufficient. Your best bet would be to contact Tom Peters @ DiscMounts and ask him (if it's not sufficient, he'll tell you) and/or ask the members of the DiscMounts yahoo group:

http://tech.groups.yahoo.com/group/discmounts/

Tom


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Trever
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Reged: 08/18/03
Posts: 3144
Loc: North Alabama
Re: Alt-Az mount for a large refractor? new [Re: Herenomore]
      #3076757 - 04/30/09 10:50 AM

At least there are other options such as the G11 or Meade Giant tripod. Also maybe a CGE tripod. I will see what I can afford and then talk to Tom Peters to see what he suggests. I would like to get the whole shebang along with the sky commander. I have never used one but I assume it is a more accurate version of Orion's?

--------------------
Trever

------------------------------------------
Celestron C 9.25 on ASGT mount
Zhumell 12 inch Dobsonian Reflector
Vixen A70LF 70mm Refractor OTA
Nikon 8x42 Trailblazer Binos
Stellarvue M1 mount
------------------------------------------



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Herenomore
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Reged: 11/29/04
Posts: 1833
Re: Alt-Az mount for a large refractor? new [Re: Trever]
      #3076952 - 04/30/09 12:35 PM

Trever:

The Orion (I've never used one...are you referring to the IntelliScope?) like the Sky Commander, Argo Navis, SkyTour, etc., are computers reading what the mount tells them. "Accuracy" is really dependent upon the orthogonality of the mount (how close the alt and az axes are to making a perfect 90-degree angle) and the quality and resolution of the encoders.

As for orthogonality, Tom Peters told me that the alt axis and az axis of my DM-4 are within 1/50 of the diameter of a human hair of being perfectly 90-degrees to each other. I don't know what that computes to in hundredths of a degree but it is, for all intents and purposes, perfectly orthogonal. You can also read Tom Trusock's review of the DM-4 in which he said:

Quote:

The accuracy of the DSC pointing depends heavily on the construction of the mount. In short, it requires that the mounts axis be perfectly perpendicular to each other – orthogonal – for best results. To make a long story short, the DM-4 is orthogonal. Period. DSC pointing accuracy was everything one could want. It easily allowed me to center objects at high power.




As for encoders, the Sky Commander will handle up to ~26K-tic encoders (the higher number of tics, the greater the resolution and pointing accuracy). Although Tom will install higher tic encoders if you request them, he recommends and uses 2" diameter 4000-tic encoders for the DM (which, btw, were the encoders installed in the DM-4 in Tom Trusock's review). Simply put, the 4K-tic encoders will give you as much resolution and accuracy as you'll ever need to bring objects to dead-center of your FOV while at the same time not taxing the Sky Commander's internal 9v power supply (the higher the number of tics, the greater the power requirement).

For more on DSC's generally, Tom Trusock has written an excellent primer:

http://www.cloudynights.com/documents/dscintro.pdf

Tom


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Tamiji Homma
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Reged: 02/24/07
Posts: 2568
Loc: California, USA
Re: Alt-Az mount for a large refractor? new [Re: Trever]
      #3076961 - 04/30/09 12:40 PM

Quote:

At least there are other options such as the G11 or Meade Giant tripod. Also maybe a CGE tripod. I will see what I can afford and then talk to Tom Peters to see what he suggests. I would like to get the whole shebang along with the sky commander. I have never used one but I assume it is a more accurate version of Orion's?




I don't know about Orion's but SkyCommander is pretty accurate with DM-6 and it makes you lazy, not looking at sky map after you are done with 2 star alignment.
If you already know what stars to choose for alignment, alignment takes less than 2 minutes, probably one minute.

Regarding DM-6 and G11 tripod, I feel the combo is solid Alt/Az solution for 6 inch f/8 scope. Here is my setup (FHD tripod, Foldable HD tripod) and DM-6. I also use Vixen VMC260L with DM-6/FHD.

Scope weight is about 20Kg (WO FLT 152 f/8, dovetail plate/rings, binoviewer, SV 60mm finder)
DM-6 and FHD tripod weight is about 32Kg.
The photo shows the lowest 47 inch high to center of dovetail. The highest is 62 inch high when tripod legs are fully extended.




Good luck in your choice and enjoy 6 incher

Tammy


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Herenomore
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Reged: 11/29/04
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Re: Alt-Az mount for a large refractor? new [Re: Tamiji Homma]
      #3076978 - 04/30/09 12:54 PM

Beautiful set-up, Tammy Looking at it, the G11 would probably be the best bet for Trever's 152ed.

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