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
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.
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, 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’ McMaster has a pretty good selection
Thank you very much for the help!