Sound proof materials?

Hi

So I'm trying to build a robotic arm a small project for local school kids and I came up to use cheap materials like SG90 servos, regulator and arduino something like the bellow pick

The only problem is that the SG90 do a lot of noise and it will be annoying to hear.

I'm planing to put all the servos in the Base cylinder box and use strings to control the hand, it's not a serious project just for kids to see and play with it.

Anyone got any idea how to make that cylinder box sound proof? What kind of materials I can use? Something that can absorbe the vibration/sound of the servos.

I’m planing to put all the servos in the Base cylinder box

I’m not quite following that, but thick-dense substances “block” sound. On a larger scale, bank vaults are virtually soundproof and recording studios are often built with thick concrete or brick walls (and often double-walls).

Unless the whole thing is sealed in the box with no way for the sound to get out, you’re not going to completely eliminate the sound. I assume you’re trying to get some noise reduction rather than complete “soundproofing”?

Soft-fluffy things tend to absorb sound. Acoustic ceiling tiles have holes & slits to “trap” the sound, and fiberglass tends to trap the sound in a similar way. (But you can’t have fiberglass around kids.) It has to be big & thick to trap & absorb low frequencies (bass) but a servo isn’t generating much low-frequency noise.

It will also help to isolate the motor from the enclosure so that motor vibrations don’t cause the enclosure to vibrate and “generate” sound of it’s own.

As shown in the photo the “box” is an amplifier of any noise created so get rid of the box.
It’s essentially a “drum”.

Fill it with non-conductive oil?

Hi, You can get sound deadening flexible tiles for the automotive trade, but not sure how thick they are. Depending on the servo, just check that you don't overheat them if you box them in.

I would have thought the noise would have been fine from those low load servos, mine don't make much noise.

Tom.... :)

I suspect that any effective sound-absorbing material will be too bulky to be practical.

Reducing paths for the transmission of sound is probably the only practical course - such as mounting the servos with resilient pads (grommets are often used) and maybe mounting the whole thing on a resilient base - a layer of foam, for example.

And, as @bluejets said, avoiding parts that cause resonance.

There was a Thread a while back in which someone was looking for a silent DC motor with gearing to drive a camera focus or zoom as an alternative to a very expensive Sony (?) part. I don't think there was any solution - which probably explains the cost of the official part.

...R

As said, the car sound deadening bitumen based pads are very effective at preventing the drumming effect.

To reduce noise, plaster board is very dense / effective if your box is big enough to use it.

Whatever you build, large rubber or foam type feet will further isolate things.

I would have thought the noise would have been fine from those low load servos, mine don't make much noise.

Then I put the servo touching a plastic material ..etc the vibrations/sound is getting absorbed by the material and the sound/noise is getting amplified. The noise is coming from the gears of the servo.

Whatever you build, large rubber or foam type feet will further isolate things.

So would be a spray foam good option?

|500x375

Putting all the parts inside, cover the sensitive / moving areas and spray the foam above and on the sides and bellow them if possible.

But.... I used in the past servos on foam and the foam transfer a lot the sound. well not sure about spray foam.

AFAIK spray foam is a hard or stiff material. You need a resilient foam. This is the sort of stuff I was thinking of as a base on which to mount things so the sound would not transfer.

Thinsulate by 3M is also very good for sound absorbtion and very light. I have it in a boat engine compartment. But is about 25mm thick.

...R

hmm

So I need a foam which will be dense, light, soft which will be able to absorbe the noise
and not transfer it to other materials.

Will this do?

That looks like it would be worth experimenting with.

...R