Pneumatics
 

Are the pneumatic pumps & accessories strong enough to power a latch or a hook?

How much work are they to install and use in place of motors?

Thanks for any info.

--Ben Mitchell

Ben, the pneumatic cylinders are faster than just about any motor for opening claws and latches and the like, but you have to keep their range of motion under control. The pressure should be regulated to ~120psi, as per the pneumatic pump rules. If you need help, I'm a stone's throw away in Hackettstown, NJ. You can call me at (908) 850-3477 any day between 7pm and 10pm. Ask for Dan from Warren Tech; there's two Dan's here, so that will prevent confusion with you talking to my dad, which would not be helpful to you...

Basics of Pneumatics
 

Hi Ben,

Pneumatics are pretty simple to use, can be very fast and powerful, and can be used for hooks and latches as you suggested.

A bit of general info on pneumatics:

The force that a cylinder can exert is simply equal to the area of the piston x the pressure (which on the working side is regulated to 60psi). According to the rules, you cannot run cylinders on the supply side (at 120psi).

For example, a 2" dia cylinder has a bit more than 180lbs of force when extending (PI*r^2 * 60psi).

Note that a rod type cylinder has a bit less force when retracting (caused by a reduced area due to the piston rod).

The extending and retracting forces for the different diameter cylinders are listed in the back of the pneumatics.

Note that a cylinder receiving pressuried air will eventually get to the force as dicated by force x area, but there are factors which effect the speed at which they get there. The reaction time to fully extend a cylinder is typically on the order of magnitude of fractions of a second. Factors which can reduce speed are not having enough volume of air and/or having restictions in flow.

Some tips on maximizing the speed are:

1. To use as much reservoir as possible, both on the 120psi side, as well as on the working side (60 psi side).

2. To minimize the tubing lengths on the working side, and to use straight fittings (versus the 90 degree fittings) to improve flow.

3. To use a higher flow valve, to ensure the valve does not restrict flow. Note that a higher flow valve has been added to the kit this year (which was provided by my company, Festo). This will improve speed on larger bore cylinders as there is less restriction to flow.

I know this was probably well beyond your original question, but I got on a role!

Hope this helps.

Scott358
Festo Corporation
Corporate Sponser of Hauppauge High