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Skywatcher HDAZ-Mount

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#1 edl

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Posted 01 June 2009 - 09:44 PM

Hello All,
I recently purchased one of these mounts (same as the Orion SkyView AZ I believe) to use with my MN56. The Mak Newt is pretty heavy for a 5" scope,and I find that balance does shift quite a bit depending on the altitude I am pointing to. Also,the nudging is not as smooth as I would like at powers above 100X, but that could just be me getting used to the thing.
Anybody else use this mount and have the same issues? Am I expecting too much? I like the light weight of unit with tripod and it is solidly built, but I understand some early Orion models may have had clutch and balance problems.

Any and all comments appreciated!

Many Thanks,
Ed L.

#2 Luigi

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Posted 02 June 2009 - 07:04 AM

I have the Orion AZ and use it with one or two 15 lb OTAs on it, an IM715 and/or the 120Eon. I'm quite satisfied with it's performance. The lower you set the friction, the smoother the movement. The alt axis passes through the center of the OTA so if your OTA is symmetric top to bottom there would be no "balance shift". In the case of the MN, you have the focuser/EP and finder making the OTA a bit top heavy which probably is responsible for the "balance shift". Counter wieghts or shifting the axis of the tube downard wrt the alt axis are the cures.

#3 edl

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Posted 02 June 2009 - 08:34 AM

Hi Luigi,

Thanks for the reply.
Shifting the axis of the tube will help for a particular orientation, but moving in altitude will also make the scope top heavy or bottom heavy. If I balance with the tube horizontal, anything above a 40 degree or so orienation will make the tube bottom heavy. A balance at 45 degrees make the tube top heavy at less that 20 degrees or so, bottom heavy above 65. I can tighten down moderately to keep balance, but then I find the movements a bit too stiff. Last night I observed the moon at magnifications up to 250x and found the mount "workable". Maybe I'm just too used to slow motion controls and need more practice.
I appreciate your suggestion about a counterweight system. I have a sliding unit on my CPC925 that I find is pretty effective switching back and forth between my Denks and mono viewing.

Best,
Ed L.

#4 edl

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Posted 03 June 2009 - 10:26 AM

I would also be curious as to the maximum magnification observers are using with this type of mount. I know it will vary depending on person, scope, eyepiece, etc. In my case, with the MN56, a 7mm Nagler with Antares 1.6 barlow (175x) seems to be the limit before my pushing and pulling causes too much over shooting of the target, while still keeping acceptable tension and balance.

Best,
Ed L.

#5 Luigi

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Posted 03 June 2009 - 11:19 AM

I don't think I was very clear in my explanation. You need to balance the tube in two orientations. Position it vertically and add weight opposite the focuser and finder to balance. Position it horizontally and move it back and forth to balance. Recheck horizontal and vertical balance. After this, balance will be independent of alt.

#6 edl

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Posted 03 June 2009 - 01:08 PM

Thanks again Luigi.
I will try adding weights opposite the focuser and re-balancing as per your suggestion.

Best,
Ed L.

#7 Starlighter

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Posted 03 June 2009 - 01:47 PM

Just curious. What do you use for weights opposite the focuser and finder to obtain proper balance?

#8 Luigi

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Posted 03 June 2009 - 01:54 PM

Whatever works. BTW, you can shift the tube perpendicular its axis and the alt axis rather than add weights. That isn't sliding the tube in the rings but moving the dovetail off center of the rings. That's what I'd do. If it can't be arranged using the existing dovetail and rings, a small aluminum plate could be fabricated to achieve the same result.

#9 edl

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Posted 06 June 2009 - 03:26 PM

A quick update-
I had my dealer checkout the mount motions and he came to the conclusion that the movements were stiff and not as smooth as they should have been (with or without OTA). He replaced the unit right away with another from stock, and the new one is MUCH better. Last night there were no problems hand tracking a balanced MN56 at powers up 240x.
Next clear night I'll atttach my Orion ED80 and try observing in dual telescope mode. Only thing left to buy right now is a pier extension.

Best,
Ed L.

#10 deezdrama

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Posted 06 June 2009 - 03:37 PM

my my eztouch handles 300x with orthos just fine, balance is the key, glad to hear your new mount is without issues.
I bought the skyview pro 16" extension and although its a bit heavy- I really enjoy it!






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