EQ3-2 Mount Vibration

[Woolnut]

Hey SGL,

I have an SW EQ3-2 Mount with the manual controls, whilst i was observing on Saturday evening whenever i was moving the 'scope a little i would have to wait a few seconds in order for the 'scope to stop shaking so i could then take a look through the EP. I was being extremely delicate with the adjustments handles and it wasn't really making any difference! If i was to put something heavy on the shelf between the legs of the Tripod do you think this will help? Or if you have any other ideas of what it could be and some prevention methods that would be great! I think i will eventually upgrade to the GoTo version (fitting the motors myself) but for the time being i am stuck with the manual adjustments

Thanks in advance

[mikeyj1]

yes some extra weight should help.  I used to have the same setup, and it wasn't as bad as your's sounds:  is everything tightened properly, (esp the main clutches), and setup on firm ground?  keep the tripod legs on a shorter setting for rigidity, and make sure the legs are splayed and tight.  Slow motion controls - the long ones are better, you have those fitted i think?  Check the scope tube rings are reasonably tight, and the whole unit is 'almost' balanced - better to have a small positive force in one direction on both the RA and Dec axis with manual controls.

Motors can help, but you should find the vibration subsides after 1-1.5 secs max with that setup, its generally considered good, although the Aluminium legs of the tripod are a weak link.

Mike

[Woolnut]

1 hour ago, mikeyj1 said:

yes some extra weight should help.  I used to have the same setup, and it wasn't as bad as your's sounds:  is everything tightened properly, (esp the main clutches), and setup on firm ground?  keep the tripod legs on a shorter setting for rigidity, and make sure the legs are splayed and tight.  Slow motion controls - the long ones are better, you have those fitted i think?  Check the scope tube rings are reasonably tight, and the whole unit is 'almost' balanced - better to have a small positive force in one direction on both the RA and Dec axis with manual controls.

Motors can help, but you should find the vibration subsides after 1-1.5 secs max with that setup, its generally considered good, although the Aluminium legs of the tripod are a weak link.

Mike

Without a detailed check it all seemed to be good when i had moved the kit outside for the evening, was on flat ground but the legs were extended probably around 40% of their max (i don't want to be hunched over all night!) I plan to give my setup a good check this evening indoors so i can take a look at everything properly, it could well be a combination of the points you have mentioned! I seem to have a longer and a shorter one (not sure which way round now though). Thanks for the ideas, if all seems well i will resort to placing a spare weight in the tray!

[wookie1965]

Fill the legs with play sand keep tapping to compress it you can hang a weight not to heavy from the eyepiece tray this will make it steadier.

[Stub Mandrel]

Keeping the legs retracted and using some sort of clamp across the upper part of the legs helps too.

This idea will ruin your warranty, but you could fit large jubilee clips around each leg.

[Louis D]

Put Sorbothane pads under each foot to dampen vibrations to under a second.

[John]

If you can upgrade the tripod to a steel tubed one (the EQ5 / HEQ5 ones will fit) that would make a lot of difference. Otherwise some good suggestions above

[Astro Imp]

I had this set up until recently and always used it with the tripod fully retracted. 

To avoid hunching over I found sitting made for a much improved observing experience.

Good luck and enjoy.

[Woolnut]

So i have had a good look at my mount and OTA and everything seems okay on the screws and other bits part! Thinking about it now i was using a 2x Barlow with a 6mm EP when i was noticing the vibrations... I guess at that sort of magnifications i am going to notice almost anything even slightly knocking part of my setup. For the time being i will keep an eye on things to see if they get worse or if in fact they get better. It could have been so many different things which i am unable to check unless i put the 'scope in the exact same spot it was on Saturday (which wouldn't be hard... but i don't see the need)

Thanks again for all the suggestions, i am hoping that i can get the gear out again tonight to take another look at Jupiter as the weather down my way seems pretty good!

[Louis D]

Just a followup to my Sorbothane recommendation.  I was out last night using my new to me 127mm Mak on a heavy duty aluminum and steel photo tripod and alt-az mount.  Without Sorbothane pads, it was all but unusable due to jittery images that took seconds to settle.  Focusing was a bear because I couldn't tell if the image was sharp due to vibrations.  With Sorbothane pads, it became a pleasure to use.  Vibrations dampened out in about 1/2 a second, I could actually reach sharp focus and see the image clearly, and I could manually guide with a light touch on the mount handle with little vibration.  It was like putting shock absorbers on the mount without adding any rubbery bounce.

[Stub Mandrel]

A wet towel hanging on the eyepiece tray might act as a damper too, or a heavy weight on a short rope. What you want is a 'loosely coupled weight' that swings at a rather different frequency to the mount's natural vibration. there are more scientific approaches, used to help stop skyscrapers shaking themselves to pieces in an earthquake. Worth trying!

[Woolnut]

3 hours ago, Louis D said:

Just a followup to my Sorbothane recommendation.  I was out last night using my new to me 127mm Mak on a heavy duty aluminum and steel photo tripod and alt-az mount.  Without Sorbothane pads, it was all but unusable due to jittery images that took seconds to settle.  Focusing was a bear because I couldn't tell if the image was sharp due to vibrations.  With Sorbothane pads, it became a pleasure to use.  Vibrations dampened out in about 1/2 a second, I could actually reach sharp focus and see the image clearly, and I could manually guide with a light touch on the mount handle with little vibration.  It was like putting shock absorbers on the mount without adding any rubbery bounce.

 

1 hour ago, Stub Mandrel said:

A wet towel hanging on the eyepiece tray might act as a damper too, or a heavy weight on a short rope. What you want is a 'loosely coupled weight' that swings at a rather different frequency to the mount's natural vibration. there are more scientific approaches, used to help stop skyscrapers shaking themselves to pieces in an earthquake. Worth trying!

Thanks for the suggestions, i will take a look and see what i think suits me best! I was out the other night and i was on the grass and the shaking wasn't too bad thankfully... Maybe i should check the decking too

[Alan64]

On 3/27/2017 at 13:40, Woolnut said:

So i have had a good look at my mount and OTA and everything seems okay on the screws and other bits part! Thinking about it now i was using a 2x Barlow with a 6mm EP when i was noticing the vibrations... I guess at that sort of magnifications i am going to notice almost anything even slightly knocking part of my setup. For the time being i will keep an eye on things to see if they get worse or if in fact they get better. It could have been so many different things which i am unable to check unless i put the 'scope in the exact same spot it was on Saturday (which wouldn't be hard... but i don't see the need)

Thanks again for all the suggestions, i am hoping that i can get the gear out again tonight to take another look at Jupiter as the weather down my way seems pretty good!

How's the view at 250x?

At that high a power, any vibration will be magnified along with the image.

Be certain to tighten the bolts where the legs attach to the mount-base.  You may wish to consider adding a lock-washer to each leg-bolt, like this...

That may require replacing the bolts with ones that are slightly longer in order to accommodate the lock-washers, and as I did for my EQ-3 there.  All of the hardware should be of stainless-steel.

[rockinrome]

You could also consider trying to get hold of a Celestron CG4 tripod. This has tubular legs and is more solid. The CG4 head is the same as the EQ3-2.

Tripod and head shown here: https://www.firstlightoptics.com/celestron-mounts/celestron-omni-cg-4-mount.html

Regards

 

[Stub Mandrel]

I have an EQ-5 tripod for my EQ3, it's the same as a CG4 and works very well.