Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: guyfrom7up on July 26, 2007, 11:51:53 AM

Title: pneumatics
Post by: guyfrom7up on July 26, 2007, 11:51:53 AM
I'm going to build a pneumatic robot, but what I need are really cheap solenoid valves, I need almost 50 that can handle up to 50 PSI, each valve has to have 3 ports and can switch between 2, also I have 1 question, what's a manifold?
Title: Re: pneumatics
Post by: Robotboy86 on July 26, 2007, 03:10:06 PM
Manifold is a peice of something(typically metal, but can be plastic and such) whos sole job is to channel SOMETHING from point a to point b.  Such as your INTAKE manifold on your car:

It takess the air in at point A, and channels it through 4,5,6 or 8 holes.

Basically think of it as a divider, takes one source of air, and divides it among a set number of paths. 

As far as buying solenoids..  look around and buy GOOD solenoids.  Nothing is worse then building the system with 50 solenoids, and have 10 of them fail.
Title: Re: pneumatics
Post by: guyfrom7up on July 26, 2007, 08:25:24 PM
so in my application a manifold is pretty much as valve, so if 1 is an intake I can make it so that hole 2 opens, letting air out while hole 5 opens at the same time.

How can you tell if it's a good solenoid?  Arn't they just integrated in the design?  I've n ever really though of solenoids as failing, by failing do you mean by them just plain out breaking, or stalling?

Thanks for the reply!
Title: Re: pneumatics
Post by: Admin on July 30, 2007, 07:00:50 PM
Quote
How can you tell if it's a good solenoid?
Just like with el-cheapo motors, you got el-cheapo solenoids . . . Get yours from reputable name brands . . . also dont buy any from china . . .

A question you might not have considered yet . . . how do you plan to control 50 solenoids? A typical microcontroller wont let you control more than 20-ish solenoids (assuming you have a driver for every single one).
Title: Re: pneumatics
Post by: LES6772 on February 13, 2008, 10:28:43 AM
If anyone is still following this thread, a parallax propeller micro controller has 32 IO pins, but still short of controlling 50 solenoids. One thing to possibly remember, is that one solenoid, is all that is required per cylinder, provided that it has the correct number of ports, and positions, Some of this is also determinate, on whether the cylinder in single or double acting, so it may be that you can actually get by with less than 50. SMC makes a multitude of control solenoids, and can opperate at many different control voltages. you can check them out, at www.smcusa.com.

Hope this helps!