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Wind/Wedge

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#1 dragon86

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Posted 23 November 2012 - 11:44 AM

I have my Cpc1100 mounted on a wedge and the unit on a tri-pod
Would mounting it on a pier give me any more stability in the wind?

#2 MikeBOKC

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Posted 23 November 2012 - 01:17 PM

Is it on the stock CPC tripod? That is a pretty heavy and solid beast. I doubt moving it to a pier would give much more stability. In wind I find that vibtations usually impact the OTA most, whatever the base mounting is. I imagine the wedge also gives some stability. The great advantage to putting any scope in a pier, assuming it is a permanent pier, is that you can then build an observatory around it, aliminating wind for good.

#3 dragon86

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Posted 23 November 2012 - 02:18 PM

I have it mounted on the stock tri-pod. It is in a permanent dome but in as little as a 2 mph wind it vibrates so I can not use my video camera. The observatory is on a wooden deck(8" centers) and the scope is sitting on anti-vibration pads.

#4 astrovienna

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Posted 23 November 2012 - 11:47 PM

Which wedge are you using? The old "heavy duty" Celestron wedge was notoriously unsteady for a C11. The new HD Pro wedge is supposed to be much better. I have a Milburn, and it's a rock solid beast.

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#5 Sorny

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Posted 23 November 2012 - 11:51 PM

The deck is likely the problem. Things will be worse if you have the tripod legs extended (it'll be vastly more stable if the legs are as short as possible).

#6 oldstargazer

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Posted 24 November 2012 - 12:23 AM

The problem is the wedge. When I put mine on the wedge it is just as you describe. With it in the standard alt/az mode the wind isn't a problem until it is pretty strong. I was hoping that putting it into an observatory would make it better but it sounds like you have done that and still doesn't help. Sounds like I am either going to scrap the cpc part and use the ota on a gem or just plain get rid of it if that is the case.

#7 dragonslayer1

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Posted 24 November 2012 - 09:45 AM

Just input from someone with the H/D Celestron wedge; Mine is a CPC 9.25 and can say even though not the CPC 11, I seriously doubt the wedge is the issue. I have found if tri pod stabilizer bottom (plate) is not tightened up as far as it will go that the tri-pod legs can allow movement and vibration, but the wedge itself is rock solid.

#8 dragonslayer1

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Posted 24 November 2012 - 09:49 AM

That wedge being the new H/D Pro I am using, just to clarify

#9 Gastrol

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Posted 24 November 2012 - 12:51 PM

The tripod sitting on the deck is your problem. You need to isolate the tripod from the rest of the structure or build an isolated pier.

#10 dragon86

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Posted 24 November 2012 - 02:16 PM

I am using the Celestron HD PRO wedge. The legs are set to the lowest point and the tri-pod stabilizer is tight. I did not have low speed wind issues in alt/az. So the question still remains. Would it worth it to install a pier?

#11 Brian Risley

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Posted 24 November 2012 - 04:45 PM

From experience, any platform where the scope is not isolated will have vibration issues. The wedge changes the angle of the weight axis from straight down with alt/az to an angle with the wedge. You also have just a few points making contact between the wedge tilt plate and the base, which is where you lose any dampening effect caused by the mass of the base. Alt-Az will always be more stable with the forks. I agree that the new tripod is quite stable, but I still use dampening pads when setup on a hard surface as it appears to help with the wind too.
At one point I had a pier made out of sand filled concrete blocks 16x16 for a C-8. It was stable, but still with a wedge there was vibration issues when touching the tube, but they were considerably less than when it was on my Golden Pyramid tripod.
just my .02.
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#12 Koen Dierckens

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Posted 26 November 2012 - 06:52 AM

I recently installed a small pier and I see the same kind of vibration-characteristics as when mounted on the tripod. With the HD wedge, the setup is way more prone to vibrations. I'm trying to figure out if I can introduce some dampening/stabilisation system on the wedge, but I don't have concrete plans yet.

But to answer your question: I don't think that building a pier will give much improvement to the stability of your setup.

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#13 rboe

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Posted 26 November 2012 - 01:37 PM

If the deck is the source of the vibrations, a pier going into the ground and structurally isolated from the deck will cure the problem.

Anti-vibration pads should help a wee bit if the deck is at fault but I suspect just how helpful it will be.

Could you share a photo of your deck/observatory setup for us?

#14 Gastrol

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Posted 26 November 2012 - 01:41 PM

But to answer your question: I don't think that building a pier will give much improvement to the stability of your setup.


But as I believe the OP has his tripod on the decking, simply isolating the tripod or the new pier from the decking should at least make a noticeable difference. Isolating the setup from the decking would be the first variable I would look at.

#15 Koen Dierckens

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Posted 27 November 2012 - 06:06 AM

But as I believe the OP has his tripod on the decking, simply isolating the tripod or the new pier from the decking should at least make a noticeable difference. Isolating the setup from the decking would be the first variable I would look at.



Agreed, but the OP also mentions that he sees additional vibration when there is wind.
In my setup, I see identical behaviour, ie the setup starting to vibrate when there is wind.

These vibations are the same when I mount my scope to the original tripod, as when I mount it to the pier.

The "vibrating factor" in the setup -when nobody is standing near the scope- always is the wedge, as there hardly are noticeable vibrations when I mount the CPC without wedge on either setup and when wind is blowing.

Of course, placing your setup on some kind of deck should be avoided and will never improve stability.






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