Flow Valves

[Hadi379]

Originally Posted by tr6scott

As GeeTwo stated the force is the same, but you may have some unexpected motion. If you have the cylinders moving independent mechanisms, you may see that one mechanism moves first, then the second mechanism will move.

Depends on static friction, hose distance from each cylinder to valve, mechanical differences.

There are times when it pays to save the money on the second valve, and times when it pays to have the second valve. Depends on quickness, and control needed.

If the hoses are cut to the same exact lengths, the two cylinders' motion should be in sync.

[tr6scott]

Originally Posted by Hadi379

If the hoses are cut to the same exact lengths, the two cylinders' motion should be in sync.

Hose length is only one of the variables. Load, Static Friction, Internal friction of the cylinders, flow control settings for each cylinder, mechanical mounting of each cylinder (variance give one cylinder a mechanical advantage than the other), fittings used on both sides, etc.

Once one cylinder over comes static friction, it will finish it's stroke first. With flow controls you can typically force the cylinders to break away relatively balanced in a FRC application, but at the expense of speed.

http://hydraulicspneumatics.com/othe...inder-movement

Much of the info on the page they talk about hydraulic and pneumatic in the same instance, but the with the compressablility of air, syncing pneumatic circuits are much harder than hydraulic.

The simplest circuit uses only flow controls to build resistance to hold the fast cylinder back. The accuracy of flow-control synchronizing is only fair to poor.