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CEM60 Mount

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#26 Astronewb

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Posted 11 August 2014 - 10:31 AM

Sort of but not really. I actually need the tip to tip distance. http://www.jimsmobil....htm#Tip-to-Tip

Oh, sorry.  The tip to tip distance from centerline of the leveler pad to centerline of the leveler pad on the 42" pier is 37.75"

 

Cheers...Paul



#27 hrgreen

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Posted 12 August 2014 - 03:45 AM

Appreciate your answer, Uncle Rod, but read it shortly after I had found and ordered a pier.   Both approaches seem to get favorable comment, and the total hardware weight and cost are similar.

 

I didn't have the Ioptron tripod extended much during testing, but when I set it up to my best viewing height, near full extension, I wasn't happy.

 

Hal

 



#28 deSitter

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Posted 12 August 2014 - 04:04 AM

Everyone should keep in mind that every setup will be essentially unique in terms of vibrations. If your weight is distributed in such a way that you are near one of the vibratory modes of your system - and everything from a feather bed to a Saturn V has excitable modes - then you will have a scope that seems flimsily mounted. The first thing to try is to redistribute the weight - if you have two counterweights, move one closer to the tube and one farther away by small increments, maintaining balance while altering the distribution of modes. The principle is very much like finding the sweet spot on a golf club or baseball bat. Curiously, *adding* weight to the system can change the modes in a good way. You cannot conclude that a mount is flimsly because you happened upon one of its vibratory modes.

 

-drl


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#29 hrgreen

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Posted 24 August 2014 - 06:57 PM

I received the 48" pier, and at 5'7", found it too high for me to feel safe placing the C9.25 alone. So exchanged it for the 42"; about right.

Have been able to try it only on a lawn so far, where I still saw vibration that takes seconds to dampen, but seemingly not as much or as long. It seems extremely rigid on my tile floor in the house, and a definite improvement over the tripod. Next: get some pads.

However, the pier is somewhat annoying to set up because the center bolt won't couple the base to the tube to aid in assembly and further stabilize things. A longer bolt was suggested somewhere, but I lost the reference.

And more annoying to take down, because one or more turnbuckle rod(s) usually won't come out of the main tube without excessive tinkering. Anchor points could be better designed.

Hal

#30 Astronewb

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Posted 24 August 2014 - 10:22 PM

However, the pier is somewhat annoying to set up because the center bolt won't couple the base to the tube to aid in assembly and further stabilize things

 

 

Hi Hal, that would be a big help, but the center bolt is only designed to hold the legs inside the tube when they are folded for transport.  One thing that you can do to increase stability is to increase the torque on the lower and upper cap screws.  

 

This is best done by removing all the panhead cap screws and replacing them with socket cap screws the same size.  The socket cap screws will have a larger allen socket and allow you to apply more tightening torque on the screws.   Caution, tight is tight...too tight is broke..:)

 

I have the 42" pier too, and that's what I did to eliminate the slight looseness in the tube.  I also put a 12v 9ah battery inside the upper tube, but that's another story.

 

Regards....Paul



#31 hrgreen

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Posted 25 August 2014 - 12:41 AM

Thanks for suggestions, Paul. This tube doesn't seem loose, but I'll probably know more when I can view from a hard surface.

Since I have to use the yard for most observing, I hope to put three small pads in, maybe buried cinder blocks or step stones.

Hal
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#32 WebFoot

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Posted 01 September 2014 - 11:18 AM

I'm curious if anyone has solved the long settling time on the CEM60.

 

In my case, it has nothing to do with the tripod; you can see the whole rig act like a pendulum around the RA gears.  No amount of tightening/loosening the RA gears makes much difference.



#33 BKBrown

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Posted 01 September 2014 - 11:42 AM

I have been following the CEM60 threads because I am considering it for field imaging with my C11 Edge and TEC 140. Sounds to me like 95% of the problems are due to the 2" tripod which is, IMHO, absolute rubbish on any mount with imaging payloads of over 20-25 pounds. My solution for the Atlas was to put it on a Losmandy HD tripod, this is a rock solid configuration and easily allowed 8-10 minute guided subs with my C11. If you pick one of these tripods up (they are often available on the secondary market) and get a local outfit to make an adapter I suspect the CEM60 would feel like a very different mount. I will be watching as the mount matures and we get more folks providing feedback on their field solutions, for now I think I will hold off on getting one myself. Good luck!

 

Clear Skies,

Brian

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#34 WebFoot

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Posted 01 September 2014 - 06:21 PM

I have been following the CEM60 threads because I am considering it for field imaging with my C11 Edge and TEC 140. Sounds to me like 95% of the problems are due to the 2" tripod which is, IMHO, absolute rubbish on any mount with imaging payloads of over 20-25 pounds. My solution for the Atlas was to put it on a Losmandy HD tripod, this is a rock solid configuration and easily allowed 8-10 minute guided subs with my C11. If you pick one of these tripods up (they are often available on the secondary market) and get a local outfit to make an adapter I suspect the CEM60 would feel like a very different mount. I will be watching as the mount matures and we get more folks providing feedback on their field solutions, for now I think I will hold off on getting one myself. Good luck!

 

Clear Skies,

Brian

Thanks, but I do understand what would be due to a flimsy tripod and what isn't.  This particular mount could be bolted to the Rock of Gibraltar, and I still would be having exactly the same issue; it's play in the RA gears, not rocking of the tripod.



#35 tazer

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Posted 01 September 2014 - 06:28 PM

This particular mount could be bolted to the Rock of Gibraltar, and I still would be having exactly the same issue; it's play in the RA gears, not rocking of the tripod.

 

 

Yep. That was my issue. 20lb Mak-Newt on the CEM60 and it would "flex" in RA with a light press. Same 20lb Mak-Newt on a CG5 wouldn't budge a bit in RA. Both were on nearly identical 2" tripods.

 

Webfoot, has iOptron gotten back to you on it yet?

 

Edit: Nevermind, I just saw your post in the other thread. Hopefully iOptron takes care of the issue promptly.


Edited by tazer, 01 September 2014 - 06:29 PM.


#36 BKBrown

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Posted 01 September 2014 - 09:57 PM

 

I have been following the CEM60 threads because I am considering it for field imaging with my C11 Edge and TEC 140. Sounds to me like 95% of the problems are due to the 2" tripod which is, IMHO, absolute rubbish on any mount with imaging payloads of over 20-25 pounds. My solution for the Atlas was to put it on a Losmandy HD tripod, this is a rock solid configuration and easily allowed 8-10 minute guided subs with my C11. If you pick one of these tripods up (they are often available on the secondary market) and get a local outfit to make an adapter I suspect the CEM60 would feel like a very different mount. I will be watching as the mount matures and we get more folks providing feedback on their field solutions, for now I think I will hold off on getting one myself. Good luck!

 

Clear Skies,

Brian

Thanks, but I do understand what would be due to a flimsy tripod and what isn't.  This particular mount could be bolted to the Rock of Gibraltar, and I still would be having exactly the same issue; it's play in the RA gears, not rocking of the tripod.

 

 

Fair enough, but several respondents complained about long settle down times and they didn't seem to have the same issue as you. If the problem is in the head assembly, it's iOptron's bad and they need to make it right. Good luck!

 

Clear Skies,

Brian







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