
Arduino programmable air, pneumatics kit - itronitron
https://blog.arduino.cc/2019/05/01/programmable-air-is-an-arduino-nano-based-pneumatics-kit/
======
contingencies
I've done a fair amount of MCU based pneumatics control. It's not difficult.
For small scale mechatronic applications the main components you want to use
are (1) valves (2) vacuum pumps (3) vacuum generators (4) filters (5) pressure
regulators

Apparently this kit only includes 1+2, but here's a few quick notes on each.

(1) Valves come in many types and are typically delimited by their orifice
type (size, connection/thread type) and pressure rating. There are
subcategories of multi-way valve, timed actuation, one way (passive) valves,
etc.

(2) Vacuum pumps replace the need for a shop air supply or small pneumatic
pressure generator with a pressure tank. However, they are drastically limited
in power and need to be mounted carefully to avoid noise and vibration
problems.

(3) These turn positive pressure from your supply side in to negative pressure
for suction applications.

(4) Filters are often used not only to remove particulate matter from air
supply side or dehumidify the supplied air, but also to introduce small amount
of lubricant oil to the circuit. Larger filter systems on shop air supplies
will use refrigeration to dehumidify more completely.

(5) Pressure regulators can be very expensive if digitally actuated. Manual
ones are quite cheap.

For larger applications you usually assume a shop air supply or otherwise
externally managed, stable pressure source.

The go to 'reference' vendor for catalogs is Airtak from Taiwan:
[http://www.airtak.com/](http://www.airtak.com/)

The world of pneumatics is actually a shadow of its former self in complexity
terms... before digital control dominated, there was broadly industrially
deployed world of nontrivial pneumatic computers which had memory, logic
gates, stacks and buffers implemented without any digital control. Apparently
the term to search is 'pneumatic logic':
[https://en.wikipedia.org/wiki/Pneumatics#Pneumatic_logic](https://en.wikipedia.org/wiki/Pneumatics#Pneumatic_logic)

~~~
grogenaut
If I wanted to learn by playing around with a home air compressor, an arduino,
and some some other devices what would you recommend starting with?

~~~
tinkrmind
Pneuduino and Soft Robotics Toolkit are both compatible with a home air
compressor, albeit running at a low pressure(<50PSI).

------
Animats
Interesting. No air cylinders, though. Precision pneumatic control is possible
if you have a proportional valve close to the cylinder and position feedback
from the cylinder. If you have a double-ended cylinder set up that way, you
have a spring with adjustable spring constant, which is very like a muscle.
That technology works fine but costs thousands of dollars in industrial grade
components. The demand is small and every application seems to need a custom
item. Like linear motors.

A gripper with little air cylinders, linear encoders, and proportional valves,
in desktop-robot size, would be fun to play with.

~~~
GlenTheMachine
This is a bit of a stretch. Proportional pneumatic actuators are highly
nonlinear. Their behavior varies dramatically with temperature, pressure, and
a host of other factors. Just having feedback and a linear control law is
generally not sufficient for, say, robotics applications. People are working
on nonlinear adaptive control laws but they are still very much in the
research domain.

Source: I do research in alternative robotics actuation and controls.

~~~
Animats
You have to get the valve very close to the cylinder for this to work at all
well, so you don't have the air in the hoses acting as an air spring. The
proportional valves have to be fast, which is usually expensive. That gets the
lag down to the point that the thing becomes stably controllable. [1]

There was an effort at CWRU to build legged robotics this way around 2008.
Site seems to be down.[2]

[1] [https://www.hydraulicspneumatics.com/technologies/other-
tech...](https://www.hydraulicspneumatics.com/technologies/other-
technologies/article/21882183/5-myths-of-pneumatic-motion-control)

[2]
[http://biorobots.case.edu/projects/onrprojects/robot3/](http://biorobots.case.edu/projects/onrprojects/robot3/)

------
Tomte
Pneumatics is fascinating.

Years ago I had a several-hour lesson in pneumatic circuits. What kinds of
valves there are, how you connect them in order to get some effect, how to
modify the pneumatic circuit, so you can replace a broken valve without the
whole apparatus moving some actor (this was a safety training, after all).

I don't remember much, I should probably look for the training material in my
basement and read it again. Not because I have any practical use, but because
it is a cool, specialized world that I haven't had any further contact with.

------
beznet
In the video at the bottom of that link, what is inside of that rubber balloon
that causes it to become firm once air is (presumably) removed?

~~~
the_gastropod
It reminds me of the Stretch Armstrong's nemesis toy, Vac Man:
([https://www.youtube.com/watch?v=xkj9ptYsjTg](https://www.youtube.com/watch?v=xkj9ptYsjTg))

It's probably small bits of foam or maybe even sand. When there's air in the
balloon, there's room for the sand to move freely, and it's "soft". When the
air is sucked out, the sand has to move past other sand, which is a lot of
friction to work against, so it's firm.

------
kawsper
It's a cool package for sure, perfect for one of the projects I have
envisioned, but $175 is a bit steep for my use, sadly.

------
ggambetta
Hmmm. For a long time I've been thinking of some sort of actuator that would
let me "feel" one bit (zero/one), without looking at it or hearing it, but
purely tactile. Maybe this is it - something pressing or not pressing against,
say, my arm. Any other ideas?

~~~
yummypaint
How about small cheap 5v relays? They can be had for a few dimes each and can
be cut into to reveal the moving parts. Even tiny ones have a surprising
amount of force. One might be able to connect to the innards to make an array
of binary actuators that could rest against skin. It would probably be hard to
beat the power efficiency.

~~~
ggambetta
Great idea, that might work. Thanks!

~~~
zrobotics
Look into braille peripherals, this is roughly how they work. A relay-sized
solenoid pushes a selected pin up so the user can read the letter by feel.

Obnoxiously overpriced, just like screen reader software, but there are Cots
products that do what you are looking for.

------
ratsbane
Only a few days ago I was playing with the little pump I took out of a broken
automatic blood pressure cuff. This is very neat, but really I think you could
buy a few such devices and scrap them for the parts for less money.

~~~
lonelappde
Arduino is expensive because they fund an Italian company and sales fund
software and website development and hardware design. Popular kit gets half
price junk-quality clones from China soonn after.

Edit: this is is not a Arduino company project, but similar issues apply.

------
analognoise
Are the model numbers for the various pneumatic parts available? I can't seem
to find them.

~~~
waiseristy
Looks like this is it?

[https://github.com/Programmable-
Air/PCB/tree/master/componen...](https://github.com/Programmable-
Air/PCB/tree/master/component%20datasheets)

~~~
tinkrmind
Here's a description of all the components-
[https://www.crowdsupply.com/img/1238/pa-parts_png_project-
bo...](https://www.crowdsupply.com/img/1238/pa-parts_png_project-body.jpg)

[https://github.com/tinkrmind/programmable-
air/blob/master/RE...](https://github.com/tinkrmind/programmable-
air/blob/master/README.md)

^ also has some other pneumatic components that didn't make it into the kit.

------
droithomme
So this is an ad for a crowd funded project, not yet shipping, which costs
$199.

I'll probably just wait for the aliexpress knockoffs that run $7.

~~~
tinkrmind
Hey, droithomme. I'm the creator of Programmable-Air. Happy to tell you that
the crowdfunding is fulfilled and extra kits are available for purchase.

The price is high, I agree. But that's mainly because the BOM cost is about
60$, the kit is large and expensive to ship, and it was fully assembled in New
York. I'm looking forward for someone to make a cheap knockoff as much as you
are!

