Pneumatic Muscle Project

[bpulver43]

I am building a mechanical arm to replicate the human arm and need to figure out how to control the pneumatic muscles. I want a hand actuated valve that works so that when two muscles are connected to the valve, they operate as an antagonistic pair (think biceps and triceps). I think that a three way toggle or rotary valve will do this but I am not sure. Here is a link to the type of muscle I will be creating: http://www.instructables.com/id/Pneumatic-Muscles/

Any suggestions about what valve would work and where it could be purchased would great, thanks

[Mark McLeod]

It seems like any of the standard pneumatic solenoids we use in FRC would work fine for this purpose.

Each solenoid has two outputs.
Each pneumatic muscle has a single input.
Use one output per opposing muscle.
When Output A is pressurized, Output B is depressurized, and vice versa.

[bpulver43]

Thanks for the reply. So would a 3 port manual valve like these work as well
http://www.smcusa.com/top-navigation/cad-models.aspx/28743
http://www.automationdirect.com/adc/Shopping/Catalog/Pneumatic_Components/Pneumatic_Valves_-a-_Accessories/Manual_Air_Valves/CVR-437D2-HL

[CENTURION]

Yep, you're looking for a 5-2 valve. Solenoid-actuated 5-2's are commonly used in FRC because you're usually working with double-acting cylinders, which require two inputs.

It has 5 ports:

Pressure in
Pressure out A
Pressure out B
Exhaust A
Exhaust B


And two positions:

Port A pressurized, Port B exhausted.
Port B pressurized, Port A exhausted.


You could also get away with a 4-2 (the exhausts for A and B are combined instead of separate ports.)

The 5-2 might be more useful than the 4-2 though, as the individual exhaust ports allow you to add two needle valves (or needle-exhausts (http://www.mcmaster.com/#pneumatic-mufflers/=muu2mu), McMaster calls them "Flow Control Mufflers") so you can control how quickly (or slowly) each of the muscles actuates.

If you're looking for a hand-operated one, just add that to your search. Good ol' McMaste (http://www.mcmaster.com/#air-directional-control-valves/=muu1op)r has a pretty good selection

[bpulver43]

Thank you very much for the help!