Anti-vibration pads

[BinocularSky]

Anti-vibration pads sit between the feet of the tripod and the ground. Their purpose is to damp the vibration that occurs whenever the telescope, mount or tripod is touched. In practice they halve its duration and decrease its amplitude.

They are also expensive (around £45 for a set of 3). This leads people to seek cheaper alternatives. The question of the use of anti-vibration pads sold for washing machines often arises, as these are significantly less expensive.

The answer is that these are not equivalent. They serve different purposes. The purpose of the washing machine ones is to reduce transmission of continuous vibration to the floor, not to actually damp the vibration of the washing machine. They are generally a hard (-ish) rubber compound) -- the rates of deformation and recovery are approximately equal. That said, they will absorb some of the vibration from a scope/mount/tripod.

The purpose of the "astronomy versions" is to damp the short-duration vibrations of what sits on top. The construction is a sandwich of sorbothane between two hard plastic pieces. Sorbothane is quick to deform, but slow to recover, hence its damping properties.

If you want to do shock-absorbing pads on the cheap, you might have better luck with sorbothane inner-soles such as are used by runners.

Alternatively, there are cheap and simple (if inelegant) mechanical ways to reduce vibrations, such as hanging a weight from the mount or hanging a chain from the telescope. Some pictures of this near the bottom of this page.

[John]

I use a set of the Meade AV pads all the time and they are very effective. The vibration damping time on my mounts is reduced by around 2/3rds so you can get on with viewing much more quickly after touching the scope.

I got mine in a sale but even at £45 I think I'd consider buying them now that I've had a chance to use some.

[BinocularSky]

John,

I agree -- I used to have the Celestron ones (no longer use them, as they don't work with my surveyor tripod, which I spike into the ground). Perhaps I could have been clearer: my comment about the expense was not that they are not worth it, but that it tends to propel people into seeking cheaper, but unsuitable, alternatives.

[Fenriz]

£45 seems to be quite expensive I have found at set at a company called Astrodevelopments. SEE HERE

Am considering getting a set, especially if you think they are really worth it.

[BinocularSky]

@ Mark: If you read the blurb here, their initial intended purpose was not anti-vibration. They are a GRP-type composition, so will not -- and cannot -- have the same vibration-damping properties as a sorbothane sandwich.

[Fenriz]

Thanks for clarifying that, can now see why the difference in price.

[Darren B]

Is £45 for a bit of kit that really does make a difference is that expensive. folks are quite happy to pay a premium price (hundreds) for eyepieces just to echt out that extra little bit of detail, but begrudge paying out for a set of VSP's that will make any mount even steadier that can do the same thing.

[John]

Is £45 for a bit of kit that really does make a difference is that expensive. folks are quite happy to pay a premium price (hundreds) for eyepieces just to echt out that extra little bit of detail, but begrudge paying out for a set of VSP's that will make any mount even steadier that can do the same thing.

Having tried them, thats my take on it as well.

The "proper" VSP's are quite a clever design with each pad comprising 3 componants. The tripod legs sit in a cup which is resting in a gel which is the vibration suppressant - they are not just 1-piece plastic or rubber pads.

[BinocularSky]

Is £45 for a bit of kit that really does make a difference is that expensive.

They do make a considerable difference, yes, and they are less expensive than upgrading a tripod and mount to a similar reduced-vibrational quality. Yes, I've used them and yes, if I had the same kit as I had then, I'd use them again.

OTOH, there does seem to be an element of "if its astro-kit, push the price up" -- reminiscent of my 12V hair-dryer, which was bought for £3.42 as a "camping hair dryer" whilst exactly the same kit was sold as a "dew gun" for prices ranging from £8.99 to £12.99! When I look at the cost of sorbothane in-soles or sorbothane sheet, and other rigid plastic mouldings, I still reckon £15+ for a piece of sorbothane sandwiched between two rigid plastic mouldings is a tad steep. I think the fact that so many people try to substitute cheaper, but entirely inappropriate, pads (which was the point of the OP) is sufficient indication that others too deem them expensive.

[simon955]

When you mentioned the material that is made of shoe-liners I imagined 3 shoes, one under each tripod leg, hehehe.

Might even work!

[Darren B]

Just seen a cheap alternative on another thread..........Tennis Balls.

The thread is in equipment discussions titled APO grab & go.

Scroll down till you see a picture of a Portamount.

http://stargazerslounge.com/equipment-help/140549-apo-grab-go.html

[BinocularSky]

Tennis Balls.

I feel an experiment coming on...

[scogyrd]

I know it's not the same but DJs have been using tennis balls to stop their records from jumping for years, they chop them in half and attach them to the feet of their turntables to absorb the vibrations from the dance floor: so, if it can stop records jumping, it might well work on scopes.

And, IIRC, squash balls are meant to be even better than tennis balls.

[jollymark]

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