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The next logical step for this mount?

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#1 Jeff in Austin

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Posted 25 July 2009 - 10:44 PM

I've been using a CG-5 ASGT for 2 years now with ok results in astrophotograpy. Sometimes I can get 2-3 minute unguided subexposures without any problems, but now I'm starting to guide and I'm running into problems with the extra weight of a guide scope and camera. The total payload is 22 lbs. My understanding is I should be around 1/2 the rated load for AP, and that means I may be overweight by 7 lbs. if the mount is rated for 30 lbs. I'm also finding it hard to balance because the RA and DEC axes have extra "stick-shun" with all the weight on it.

So my question is, am I at the limit for AP with this mount? And if so, what's the next logical step up in mounts for AP? Or - should I just be looking for ways to lighten the load?

#2 Nebhunter

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Posted 26 July 2009 - 02:20 PM

I'm not an expert with this particular mount, but your symptoms are similar to what I experienced with the EQ6 once I began loading it up for AP.

I'm quite sure you have reached the point where the mount is over stressed for accurate AP. Seven pounds is a LOT of weight to try to loose. Where do you start. You can't skimp on the mounting brackets, as mass and solid connections ensure no flexure issues. You would either need to go back to unguided - or move up in mount size.

My EQ6 would easily handle your weight. What scope are you using for AP? If it's a longer refractor it could be a torque issue. I can offer you this suggestion. If you bet another mount, get the best mount you can afford - either used or new. My buddy out west and I thought the EQ6 was a good mount for the money, and there are other offerings out there now in this size range. However, if there is one thing we have learned from this hobby, especially during the first few years, that there are always many changes to the equipment as we develop and progress.

Just when you get settled with an ideal setup - we tend to upgrade. The mount is the limiting factor, and can make or break AP. Getting a larger mount allows for future changes without having to upgrade the mount - again. I got a great deal on a used G11, and my buddy got a used CGE. Both of us are very happy with our upgrades, and one look, and first light with the mounts showed us how much more superior they are over our previous models.

#3 Jeff in Austin

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Posted 27 July 2009 - 09:00 PM

I'm using a SV102ED for imaging at the moment...but as you pointed out, it's just "for now". I also have a C8 that I could use. Your suggestion to get the best one I can afford sounds like good advice. The Atlas seems possible but maybe a minor improvement, or maybe a used Losmandy. If I had an Observatory there would be no question on getting a massive beefy mount, but I'm in the driveway most of the time and I'll need to set up and tear down nightly. Right now I can lift the mount and OTA's with 22 lbs in counterweight and carry it 60 feet or so to my spot. But just barely, and I'm not getting any younger :)

I'm thinking a new rig would be considerably heavier, so a few trips would be needed. Not a big deal, though. I guess it's time to check the classifieds to see what's out there.

#4 Joe Aguiar

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Posted 28 July 2009 - 06:48 PM

that mount is a EQ5 i had it & also have the meade version LXD-75 very similar mounts. I am not sure who said it rated for 30 lbs but thats incorrect EQ5/CG5 mount even with 2" steel legs are rated for 20 to 22 lbs limit.

The HEQ5 is rated to 25 to 28 lbs & the EQ6/Atlas can do 30 to 33 lbs realistically.

Now maybe your eq5 can do a mx of 30 lbs but that only for visual & if the tripod is all the way done & hopefully there no wind.

Joe

#5 Luigi

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Posted 29 July 2009 - 09:18 AM

>>>CG5 mount even with 2" steel legs are rated for 20 to 22 lbs limit.<<<

Celestron upgraded the CG5 and upped the tripod to 2" legs when they started packaging it with a C11, which is essentially a 30 lb OTA. That suggests a manufacturer's limit of at least 30 lb. That's more than I would put on it for stability reasons, but at least it shouldn't collapse under the weight. Many do excellent guided AP with CG5s and loads </= 20 lb or so. Mine works great with my 15 lb OTAs.

#6 Joe Aguiar

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Posted 29 July 2009 - 04:03 PM

thats kinda what i was saying that mount is not rated for 30 lbs even tho they say it is even with the better legs maybe for visually it may be boarder line but not for AP.

Myself i would not load much more than 20 maybe up to 23 max.

Joe

#7 Jeff in Austin

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Posted 29 July 2009 - 08:19 PM

My CG5 doesn't seem like it can take more than the 22 lbs I have on it now, so you could be right, Joe. And forget about running it on a power tank with a 22 lb load, it needs AC power on long slews like a meridian flip.






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