Need help / Question concerning pressure in inflatable toys

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Blacky
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Need help / Question concerning pressure in inflatable toys

Post by Blacky »

Hello everybody :hi:

Over the last few months I've been playing around with some Arduino based projects.
I am now close to having the knowledge I need to create a mobile setup that is supposed to contain an inflatable buttplug.
What I'd like to be able to do is to let that plug be inflated by a (preferrably small) pump that should be Arduino-controlled.

My problem now is, that I have absolutely no idea how much pressure will be needed to inflate the plug.
The second part of the problem is that I'd like to be sure that the pump will not create too much pressure, as I don't want to risk injury. :shock:

Can anybody here provide any reliable data concerning the minimum and maximum pressures that are going to be needed respectively should not be exceeded?

Thanks and kind regards,

Blacky
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Re: Need help / Question concerning pressure in inflatable t

Post by OrgasmAlley »

I don't exactly have an answer to your questions as asked, but I'm happy to share my solution to what you're trying to accomplish.

I started with a blood pressure monitor like this: https://www.amazon.com/Pressure-Portabl ... ssure+cuff

As you'll probably know, in measuring BP this device will inflate a bladder inside the wrist band, and after some measurement period, release that pressure. You will find three useful things inside: a very small air pump, a small solenoid air release valve, and a pressure measuring chip. The first two are quite easy to convert to an Arduino-driven inflatable inflator. The tubing in mine was the same size as some silicone RC fuel tubing I have around. Wiring is quite simple... these are 3V devices, and I wouldn't run one from the on-board regulator. Use a MOSFET for on/off for each one.

The pressure chip is a bit more challenging. Frankly, I have not gotten around to working on that piece just yet. In theory, one can get an extremely accurate measure of the device pressure... accurate enough to see the wearer's heartbeat, obviously. However, it requires a signal amplification circuit and some playing around that I haven't had time for. Right now, my setup uses only time. I set maximum inflation based on runtime of the pump from fully deflated. Coarse and dirty, but it works.

The pump works surprisingly quickly for such a tiny device. I do not have confidence that it has much of a duty cycle, and would suggest assuming 10% to be safe.
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Re: Need help / Question concerning pressure in inflatable t

Post by BornThisWay »

I'm speculating and can't back anything I'm saying with any fact, but if you want my 2 cents on the matter here is my humble educated guesses and suggestions.

Assuming you are using a butt plug such as the "swell guy" then it's not a matter of pressure, it's a matter of volume.
What I mean is, it's basically a latex cover over a butt plug. And it will act much in the same way a latex balloon acts when you try to blow it up with your mouth.
It takes a lot of pressure to get it started, but once you get over that initial threshold, it takes much less pressure to continue and it's relatively easy to blow it up.
If I were to tackle this problem, I would have a measured reservoir of air to draw from and once it's depleted, then no more air would be able to be transferred.
Maybe if you had a enema/hot water bottle "bladder" attached to the input of the pump, so the pump would draw air from the bladder into the butt plug, Once all the air was out of the bladder, the pump would not be able to inflate the butt plug any larger.
Your enemy of course would be leaks in the line, because if outside air leaks in, you're butt plug would get much bigger than you expected or may be able to handle.
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Re: Need help / Question concerning pressure in inflatable t

Post by Riddle »

May I suggest an experiment to find the minimum and maximum pressures? Connect a pressure gauge inline with your inflatable plug and watch the pressure as you inflate it. Probably start with a 30 psi gauge and see if you need a different gauge.

I would also be concerned with the volume of air going to the plug. When you find a pump, see how long it takes to inflate it and set a time limit on running the pump.

Please keep us informed of your progress.
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OrgasmAlley
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Re: Need help / Question concerning pressure in inflatable t

Post by OrgasmAlley »

A couple of things.

It certainly is a matter of pressure... for any device pressure creates volume in this application. Air is a highly compressible medium, and we're not talking about a toy in free air but inside a cavity surrounded by muscle. "Too much" will be defined by discomfort or actual damage to the surrounding tissues while being used. Obviously you don't want to blow out the toy, but any design worth a damn will eliminate that possibility in proper use.

The answer will be very toy and use specific. I have inflatable toys ranging from a Mr S gag to a plumber's test plug (used to plug a sewer line to pressure test a house)... the former will be on the order of 2-3 PSI, I think, while getting the latter to start inflating is somewhere around 40 PSI. I believe a typical rubber inflatable toy will be in the 3-5 PSI range, but that's a guess. You would have to test in situ.

Because of the variability -- based on the toy, the cavity, the toy size, the subject's pain tolerance, and the desired effect -- I use an instance-specific approach. That is, part of the start-up procedure for the Arduino is to set the maximum inflation. Currently that's done by starting the pump, inflating to the maximum extend, and setting that amount of "on" time as the top end. I've found that one needs a pre-measurement cycle to get repeatable results... inflate some, deflate, then start inflation to maximum. Every setup will result in its own level of evacuation, and the resulting "0" level may not be the same as the toy has at first insertion.

Adding the pressure feedback circuit will allow much more precise changes, and especially partial deflation. Right now, the toy has to be fully deflated to count up from 0 to get a sense of percentage full. The pump has a little ramp up, and does leak a bit.
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Re: Need help / Question concerning pressure in inflatable t

Post by lj »

From a pneumatics point of view, the behaviour of air under pressure, like electricity, depends on a number of factors.

I suppose the air equivalent of voltage is pressure, that "drives" the air flow/current. Capacity of the storage tank would be equivalent to the battery capacity - ie the ability to supply a quantity.

Electricity is dangerous when the voltage and battery (more accurately the supply) capacity are high, the same for air. I remember working as a tyre fitter during student vacations - there was a photo of the white outline of a human body, like the police outlines of murder victims seen on old films. The catch was the outline was drawn on the workshop ceiling, where the man was blown by the exploding truck tyre he was leaning over. Capacity and pressure were both high. He died.

The human body is not designed to have air directed into it much above atmospheric pressure (which is equalised by the body pressures) so you need to exercise great caution using insertable air toys. Back to the tyre fitting days, we were warned never to use the airblow-off guns anywhere near your own or someone else's anus. Even without insertion, the air blast from a blow-off gun held inches away from the rear end has caused serious internal damage.

If you are going to trust your life to an Arduino, make sure you have a pressure relief valve that will cut out the pump, though how you will determine the safe pressure I have no idea. As a professional Electronics Engineer I wouldn't even contemplate doing this. Get a two-legged partner with experience of inflatable toys.
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Re: Need help / Question concerning pressure in inflatable t

Post by Keyless »

lj wrote: The human body is not designed to have air directed into it much above atmospheric pressure (which is equalised by the body pressures) so you need to exercise great caution using insertable air toys. Back to the tyre fitting days, we were warned never to use the airblow-off guns anywhere near your own or someone else's anus. Even without insertion, the air blast from a blow-off gun held inches away from the rear end has caused serious internal damage.
I say, listen to this. I too have seen an accident report about blowing an air line up someone's behind. It sounded as though the result was indeed very serious.
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Re: Need help / Question concerning pressure in inflatable t

Post by Gregovic »

If those warnings are not enough and you have strong stomach, google for pneumatic injection injuries. The fact there is a medical trauma term for it should provide some warning in itself.

This is one of those things that sound great in theory but the risk of just a small error resulting in grave injury us just too great imho.
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Re: Need help / Question concerning pressure in inflatable t

Post by BornThisWay »

I took a penny out of savings, I just wanted to clarify in case I was misunderstood so here's my three cents worth.

If the inflatable is latex, then you are not going to be able to have any consistency with pressure. The more you use it, the less pressure you will need to inflate it.
It's like a party balloon, Hard to blow up when its new, easier the second time.

Now if you add a condom on top of it, it's really unpredictable.

When I said "it's not about pressure, it's about volume" I wasn't trying to dismiss the dangers of too much pressure, I was trying to point out that the pressure is going to be unpredictable.

What CAN be controlled, however, is the amount of air available to be pumped. Once you determine how much volume is your limit, then only put that much in your reservoir.

When your reservoir is collapsed then no more air can go into the inflatable.

I suggested a hot water bottle as a reservoir because it's very durable and designed not to leak and comes with a nice hose.

**** And here's the best part of this idea, you can incorporate it with everyone else's idea of trying to determine air pressure. It can be a type of fail safe against a runaway pump.
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Re: Need help / Question concerning pressure in inflatable t

Post by OrgasmAlley »

Found this picture of the inside of the BP monitor on my phone. Rather remarkable little plastic pump, just 1.25" long. Shown are the pump in the upper right, solenoid on the left. They hook together at a fitting that connects to the bladder behind the case part shown, and also to the pressure sensor ( a chip with a tube coming up from it) on the board that goes over this area. I suspect that the blue fitting center-right is a pressure limit, as it also connects to the bladder and to nothing else.

Not only can a decent quality inflatable toy be expected to lose virtually no elasticity for many cycles, assuming it's not over-inflated, it will provide a far lower percentage of the inflation resistance than the cavity in which it is placed, unless it's something like a long dildo that will be hanging half out. Just my experience.

I have to suspect that those reading are adults, and able to make their own choices about their play. Arduino are, by the way, extremely reliable. Atmel microprocessors like and including the ATmega 328P used on most current boards run all manner of equipment.
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Blacky
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Re: Need help / Question concerning pressure in inflatable t

Post by Blacky »

Thanks a lot for all your input. I'll take every bit of it into account. :love:

Special thanks for the warnings, too. But I never intended to create pressures that could in any way be compared to those used for the inflation of tires! :shock:
I do appreciate the warnings though, as they will (possibly) keep others from trying to recreate my project and literally blow themselves up.


I'll most likely stick to the route outlined by OrgasmAlley.
It seems to be rather cheap, reliable and not oversized or overpowered.

Of course I'll test, re-test and then test some more before I'll expose myself to any such creation of mine.

And of course I'll keep you informed.

Once more, thanks a lot. This community is awesome! :love: :hi:
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Re: Need help / Question concerning pressure in inflatable t

Post by FatherOfFour »

Hi,
As someone playing with pneumatic mechanisms and all sort of cheap compressor solutions, I'll throw in and hope not to rain on Your wedding:
A. - First of all I would be afraid of leaks _inside_ the body. No one talked about embolism risk, and our rear end is almost an open interface to our bloodstream (see survivalists "drinking" dirty water thru enemas).
Please take into account I've never used such toys, but worked with all sorts of inflatables and, sooner or later, all leak. I guess a condom over it it's not enough...
B. - By using a pressure gauge - they are all sensitive enough (built one myself, but it was bulky...) - You could detect leaks, and stop the session at once.
C. - From a "Dom" point of view, I'd like to inflate my sub's toys as a "surprise", so I'd use a reservoir and regulator (2Lx80psi = 40Lx4psi), so no pump-noise would alert about what's going to happen, also You could inflate _very_ slowly (remember the frog in the hot water?)...

I'd like to know - from someone using inflatable toys - when squeezing the sphincter muscles (like kegel), does pressure rises? It could be read by the sensor and act upon it...

Have fun, pump slowly...
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Re: Need help / Question concerning pressure in inflatable t

Post by OrgasmAlley »

Introducing air to the colon does not, to my knowledge, present an embolism risk... not to be too explicit, but there's no fart-to-bloodstream risk, and none for room air either. Although there are a series of muscle gates along the way, the anus is essentially a direct vent to... the mouth.

Yes, pressure certainly rises when one clenches. In fact, this is one of the useful ways to attempt to electronically detect an orgasm.
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Re: Need help / Question concerning pressure in inflatable t

Post by lj »

OrgasmAlley wrote: I have to suspect that those reading are adults, and able to make their own choices about their play. Arduino are, by the way, extremely reliable. Atmel microprocessors like and including the ATmega 328P used on most current boards run all manner of equipment.
Having moderated this forum for several years, I would like to agree with you, but have to say that there have been several occasions when I have seriously doubted the sanity of a member, judging by the content of their posts. We regularly refer to not thinking with your hormones.

As an Electronics Engineer of over 35 years experience, including many years of writing microprocessor code and designing microprocessor systems, I agree that Arduino etc are perfectly OK as pieces of electronics, but like all electronics, can fail unpredictably. Programmes, whether firmware or software can be subject to bugs that may not be detected during initial testing, and random spikes can derail code, also unpredictably.

I see the role of moderator as bringing to people's notice possible risks, based upon personal experience and knowledge. What they do with it is up to them.
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Re: Need help / Question concerning pressure in inflatable t

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lj wrote:I see the role of moderator as bringing to people's notice possible risks, based upon personal experience and knowledge. What they do with it is up to them.
I agree. Moderators moderate what happens on the forum. We try to put a little inertia in what could be dangerous over-enthusiasm. However, what happens after a user logs off is entire up to them. We just want to hear from them when they next log on, not when they're featured in a newspaper, or worse, an obituary.

How?

WIth our experience, our knowledge, particular skills, etc. My own experience goes back to when Nixon was president - I'm sure lj's is of similar vintage. If we can share that with others, that's a plus.

Why?

Because we care.

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