# Need number help buddies

How much force can be produced by one 3/4 inch piston and how fast does it go in meters per second. Would really appreciate the help.

First of all, how much PSI are you running to it? I’m assuming 60psi, so I’ll calculate it as such.
60*.75*3.14 = 141.372
You will produce approximately 141.372 Newtons of force. Using some kinematics equations, you can find the speed.

Uh, it looks to me like you multiplied pressure in pounds per square inch by piston circumference in inches, and reported the result as force in Newtons. It doesn’t work that way.

The correct calculation is 60 lbf/in^2 x pi()*(0.75^2)/4 in^2 = 26.5 lbf.

That force could also be expressed as 118 Newtons.

My mistake. Thanks for the correction, Richard.

OK, well wouldn’t another important question be:
Over how much time does this piston extend, as that is the main factor in how useful this force is.

wow you guys are prompt and very helpful. the piston to my knowledge extends in about 1/4 -1/2 second, but the force was my really needed information , so thank you all so much.

does anyone know what the force needed to fire the ball over or at least the equation to find it.

Our last prototype, which was pretty crude and not very efficient, used 135 ft-lbs. to launch the ball 8" vertically. We invested in a 250 ft-lbs. gas spring and are creating a complex lever system to add some extra oomph, but I wouldn’t invest much time in attempting to use pneumatics to fire a ball.

What if you fire off 3 3/4 inch pistons to break the balls needed initial velocity then 1/2 second later fire off 5 more with longer shafts. at 26.5 ftlbs each it should work and the increase shaft size will direct it and add a kick. now does this work math wise or am i mistaken.

The exact speed at which a cylinder fires will depend on the stroke length, inner diameter of the tubing, which solenoids you’re using, and your accumulator configuration. Generally speaking, however, cylinders fired without flow controls will extend in well under a second.

What if you fire off 3 3/4 inch pistons to break the balls needed initial velocity then 1/2 second later fire off 5 more with longer shafts. at 26.5 ftlbs each it should work and the increase shaft size will direct it and add a kick. now does this work math wise or am i mistaken.

If you have a mechanism to guide the ball at the fire point, this technique could work. With four tanks you’ll have plenty of air to fire it, and it seems to check out mathematically. You’ll need to make sure that each set of cylinders is firing perfectly in sync so they all contact the ball at the same time. I would recommend doing lots of testing with that design.

Ok, i’m the head of pneumatics for my first year team, what is the best configuration for a single piston at a 45 degree angle? can you please explain how everything work together?

Then you run out of air :D.