Achieving The Pneumatics Bshoooo
 

So one thing has been perplexing me for a while now and I figured I may as well open it up to the community here to find answers.

Some teams have pneumatics that make a beautiful "bshooo" sound when fired. Assuming it was simply a specific solenoid I went around at champs and asked some questions. As in any great mystery the noise could not be replicated. Several teams who made the noise had different solenoids and really couldn't explain why it happened.

Does your robot make this glorious noise? If so what is the secret? I will not sleep until this is resolved.

The magnificent solenoid call can be heard in the video below between 4 and 8 seconds in, as well as various other times.

https://www.youtube.com/watch?v=PtRewwr59d8

Thanks
~DK

Re: Achieving The Pneumatics Bshoooo
 

Hhm, my guess would be that it is a certain bore cylinder combined with a certain flow rate. Our 2" bore cylinders did not make the bwoosh sound that you are talking about, they did more of a "ksshhhchung!"

Re: Achieving The Pneumatics Bshoooo
 

Might it be due to flow restrictors installed on the cylinder's exhaust? They can easily turn a "PSSHUNK" into a "FSSSSH" sound.

Re: Achieving The Pneumatics Bshoooo
 

I usually hear this with very small bore cylinders with no flow restrictors. In other words, I think it has to do with the velocity of the cylinder rod.

But I could be totally wrong.

Re: Achieving The Pneumatics Bshoooo
 

It seems like the noise comes from a small bore, short stroke cylinder supplied with high pressure (60psi)

Re: Achieving The Pneumatics Bshoooo
 

I have noticed different solenoids and manifolds make unique sounds when they exhaust.

Re: Achieving The Pneumatics Bshoooo
 

Re: Achieving The Pneumatics Bshoooo
 

We use this for our brake on our Tote Lift (not used at champs). It makes that same distinct sound when extending. Not sure if all pancake cylinders do that.

Re: Achieving The Pneumatics Bshoooo
 

^This

Re: Achieving The Pneumatics Bshoooo
 

Our pneumatics always seem to make a lot of noise, the prime example being 2013 when you could hear our pneumatics actuate from just about anywhere in the arena.

Midwest Regional QF 3-1

We're the corner climber... not exactly sure what caused that, but those were 1.5" bored 2.5 foot stroke that year. (We were and are slightly crazy)

We use the SMC base stations and double action solenoids through Vex.

Re: Achieving The Pneumatics Bshoooo
 

This thread has given me an amazing idea. Now to convince the team to use it for next year

Re: Achieving The Pneumatics Bshoooo
 

we did a whistle for our pneumatic actuated claw... We could hear it from the 3rd floor at the Edward Jones dome...
the whistle was made of tubing with an angle cut in it, in the solenoid exhaust, and weights only a few grams.
You can here it here when our claw opens - http://www.thebluealliance.com/match/2015qcmo_qf1m4

Edit: it does not make 118's Bshooo sound, but more of a Tchoo/Tchuiii

Re: Achieving The Pneumatics Bshoooo
 

Especially in the high frequencies, the primary sound you will hear from a pneumatics cylinder is the exhaust, as sound from air flow within the system will be attenuated twice, once as it goes from air to plastic or metal, and again as it goes back to air.

I suspect that the major part of the sound in most cases is during the initial decompression of the compressed air, before the piston has moved very far. For a given exhaust port size, a larger volume piston will create a longer sound with a more gradual reduction in pitch, a smaller piston a shorter, sharper sound. Sound duration is determined by volume.

Just as with a brass or woodwind instrument, The pitch of the radiated sound will depend primarily on the length of the run from the exhaust port to the end of the tubing; a shorter tube will produce a fundamental frequency with a higher pitch.

As you look at robots that make the sound you desire, focus on the exhaust end first, from the exhaust orifice outward to get the pitch, then on the cylinder size to get the duration/decay rate.

Re: Achieving The Pneumatics Bshoooo
 

Are we really getting to the point where the sound of the robot is an indication of build quality?

Coming in 2016 on a Scouting Form Near You

Re: Achieving The Pneumatics Bshoooo
 

Designing for sound makes exactly as much sense as designing a pretty robot. We can count on 1114 to not design for sound just as much as they don't design for pretty, and for the same reasons. Think about all of the distinctive, even identifying, machine noises you've heard:

• A Harley's pa-thut pa-thut in idle.
• A classic VW Beetle's trilled purr (copied by George Jetson's space car about an octave up)
• The throaty roar of a classic Mustang
• The solid thunk of a steel car door
• The heartbeat of a grandfather clock
• Practically every machine in the Star Wars universe