How do you calculate force of a pneumatic clamp

Is there a way to calculate the force of a pneumatic clamp? like a formula? We are trying to find out if we use our back 2 bar or our pneumatic clamp for auton, and the pneumatic clamp is preferred but we don’t know how strong it’s clamp is. Our pneumatic clamp looks smt like thisimage
The red is the piston we use (we fill it to 100 psi right before auton), the yellow is the clamping part

Based on Vex’s pneumatics page, the maximum force a piston can output (at 100psi) is 12lb.

When you have a pivot point, like in this situation, such a problem can typically be solved using torques. Torque is the distance from the pivot point, times the force perpendicular to the pivot point. Here, 12lbf * x, where x is your distance from the pivot point, is the torque (assuming your piston is perpendicular, or close to it, at the target clamping position).

The sum of torques has to be zero since there are no other torques around the pivot point. The force there can be calculated using 𝜏 = -12lbf * x + F_output * x2. x2 is the distance from the pivot point to the clamp. It’s negative because it’s clockwise.

Then you can solve the equation by inputting the distances between your pivot point - piston and pivot point - clamp.

𝜏 = - 12lbf * x + F_output * x2
𝜏 = 0 (since no acceleration)
Learn more

This info is all from my AP Physics 1 class, so such a course would be a good place to learn more (not just for OP but anyone who wants to solve similar problems).

5 Likes

Here is a great resource that you can use to calculate the force (depends on the angle and force applied)

Use this as force

3 Likes

Despite this physics-y post above, I can personally attest that a pneumatic clamp, if mostly perpendicular and all, works perfectly fine even at lower pressures. As I found out in recent tournaments, it can stand up to a huge fight against a motor clamp at higher pressures.

The fight I'm talking about

https://youtu.be/VpaUIVsU8H0?t=31524
In the tug of war blue is pneumatic (my team), red is a motor clamp

3 Likes

will the pneumatic clamp last for a whole 2 mins by this I mean have a good amount of pressure when using the clamp over a period of time?

If you have no leaks, the air cylinder will give constant force. Air cylinders only consume air when they are extended or retracted. (Single-acting cylinders do not consume air when they retract). If you have a small leak, you’ll get constant force until the air pressure drops below your regulator pressure setting, then the cylinder force will drop as the air pressure runs out.

7 Likes

It work like water work you nned to know the math for it to work and try to use diffent numbers