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EQ mount for 45lbs cassegrain OTA?

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#1 stanislas-jean

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Posted 06 May 2011 - 12:42 PM

This is in the title.
For the momment I own a M12 OTA installed on a modified EQ6 (bearing replaced and small gears too).
This is decent visually, tracking is hold well with a out balance of say just a kg. Stability in small winds remains problematic.
Which EQ mount can be selected in order to get say a step above for stability, tracking and out of balance ability?
Thanks for your experience and observations about.
I found possible the IEQ45, the CGEM-DX and the G11.
Not actually convinced by the G11 with the aluminium geared wheel.
Jean

#2 skybsd

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Posted 06 May 2011 - 12:45 PM

1] What purpose? Visual? Photography?

2] What FL is your OTA?

3] Is that 45lbs description the bare OTA or total including accessories per [1]?

4] If a dew shield is required, how long is that?

Regards,

skybsd

#3 Bowmoreman

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Posted 06 May 2011 - 02:20 PM

This is in the title.
For the momment I own a M12 OTA installed on a modified EQ6 (bearing replaced and small gears too).
This is decent visually, tracking is hold well with a out balance of say just a kg. Stability in small winds remains problematic.
Which EQ mount can be selected in order to get say a step above for stability, tracking and out of balance ability?
Thanks for your experience and observations about.
I found possible the IEQ45, the CGEM-DX and the G11.
Not actually convinced by the G11 with the aluminium geared wheel.
Jean


Jean, if you are not convinced by the G11, then you can FORGET about the CGEM and IOPTRON...

For Visual, the G11 should be more than sufficient; for AP, it might be dicey, unless you are doing a lot of focal reduction, etc...

Same thing with a CGE (used) - visual - OK, AP - dicey/maybe

I'm afraid that if you want something MORE substantial than the G11, you are into the next "class" of mounts:

AP Mach1GTO (visual; would be tough for AP)
AP 900
Losmandy Titan
MI-250 (used)
Tak NJP (used), or maybe EM-400 (EM 500 easy!)
CGE Pro, etc...

Why specifically are you "not convinced" by G11?

#4 stanislas-jean

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Posted 06 May 2011 - 03:56 PM

Same overall size with regards to an EQ6 which works decently to-day already.
OTA is a M12 SCT.
What I note better is the size of the worm gears (143mm) and the elevation adjustment device more designed for stability.
Think the M12 fork (lx200) should be better globally, but have not here.
Jean

#5 stanislas-jean

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Posted 06 May 2011 - 04:05 PM

The scope is a M12 sct for visual and planetary ccd up to 30s set.
You may add a due shield protection as well a camera and a small spectro.
I donot want to modify constinuously the balancing of the mount (to-day the eq6 can absorb a small out of balance up to 1kg) making also continuous re-collimation (M12 keeps its) or re-center object into the field of view (eq6 not too bad on this point).
Here is the situation to improve, being just at the limit with the eq6.
Jean

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#6 stanislas-jean

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Posted 06 May 2011 - 04:12 PM

About the CGEM, I was thinking about the CGEM-DX version that according celestron can bear a C14, so 45lbs.
This could be investigated.
Jean

#7 skybsd

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Posted 06 May 2011 - 05:23 PM

Hello Jean,

The scope is a M12 sct for visual and planetary ccd up to 30s set.
You may add a due shield protection as well a camera and a small spectro.
I donot want to modify constinuously the balancing of the mount (to-day the eq6 can absorb a small out of balance up to 1kg) making also continuous re-collimation (M12 keeps its) or re-center object into the field of view (eq6 not too bad on this point).
Here is the situation to improve, being just at the limit with the eq6.


Thanks for that background information..,

I've no easy news for you, unfortunately.

At your current payload, you're not only above the stated capacity of your current mount, but at the threshold of the G11 (the next capacity jump up) as well - most certainly for field-based photography. Note that this is catering for the fact that the G11's HD-Tripod is arguably the most rugged and stablest tripod-based platform - anywhere.

Note that permanently mounting in an observatory, protected from the wind does give you a fighting option here - but again, only at a substantially reduced FL for photography.

From a price point of view, your next would be in the CGE-Pro range, but even with this option, I'd still be tempted to install the CGE-Pro head and pillar onto the Losmandy HD-Tripod for field photography.

I'll pause here - let you review what I've posted here and continue thereafter..,

Hope this helps somewhat..,

Regards,

skybsd

#8 jrcrilly

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Posted 06 May 2011 - 08:29 PM

I donot want to modify constinuously the balancing of the mount (to-day the eq6 can absorb a small out of balance up to 1kg)


If you want the mount to tolerate an out-of-balance condition you may not love the G-11 clutches; they can't be locked and are intended to slip easily.

If the EQ-6 (an EM-200 knockoff) nearly does the job then a real EM-200 would probably make you very happy. A used EM-200 would cost a little more than a used G-11/Gemini or about the same as a new one.

#9 stanislas-jean

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Posted 07 May 2011 - 02:10 AM

Thanks gentlemen for your feelings and experience reported here.
In a certain way this is confirming my expectations about.
Thanks again.
I will see an alter D6 mount that some UK retailers are proposing a little more expensive but rugged for 100lbs with no goto.
Jean

#10 skybsd

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Posted 07 May 2011 - 02:16 AM

I will see an alter D6 mount that some UK retailers are proposing a little more expensive but rugged for 100lbs with no goto.


Jean, where are you located, and what is your budget?

Please ensure you research that D6 before committing to buy.

Regards,

skybsd

#11 stanislas-jean

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Posted 07 May 2011 - 05:32 AM

For visiting a UK retailer, I have just to cross the channel and to to go to Widescreen in London, they have one at the store>
Personnally I own a TAL mount, this is rugged sharp and efficient> Easy to perform a maintenance> I replaced the synchronous motor in AD axis with one more powerful of 5watts>
This is a kind of truck now>
Said like this, effectively this shall be examined carefully with 3000£ investment.
I am located near Paris.
Faithfully.
Jean

#12 skybsd

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Posted 07 May 2011 - 05:52 AM

Hello Jean,
Good to hear from you..,

For visiting a UK retailer, I have just to cross the channel and to to go to Widescreen in London, they have one at the store>
Personnally I own a TAL mount, this is rugged sharp and efficient> Easy to perform a maintenance> I replaced the synchronous motor in AD axis with one more powerful of 5watts>
This is a kind of truck now>
Said like this, effectively this shall be examined carefully with 3000£ investment.
I am located near Paris.


I know that shop and I remember seeing that mount about two years ago when I was last in Widescreen. The mount's been advertised on their website for years now.

You'd want to make sure to request an in-store demo and about exactly what else is needed in order to start using the D6 that is in the shop.

If its of any help, you may want to consider alternatives like this in Ireland.., or giving Markus at APM a ring to talk about that used NJP on his website..,

Best wishes, Jean..,

Regards,

skysbd

#13 jrcrilly

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Posted 08 May 2011 - 11:12 AM

Here's a suggestion: There's a Tak NJP/Temma in the CN Classifieds for about the price of a new G-11. That'll carry a Meade 12" easily (capacity is a very conservative 65 pounds; no derating necessary) - and will have the tracking performance to work really well at that focal length.






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