I am working on automating my lens sled.

At work (Oil and Gas processing plant) we use air to control everyting. Louvers on fans, valves, etc. A pneumatic cylinder/actuator is cheap, fast, quiet and accurate.

Here's my thoughts: Run a supply air line from my garage air compressor to a 120V solinoid valve, then to the actuator/cylinder. I thought that if the solinoid is 120V I can simply power if from a light switch which I can control from my remote control, and shazam I should have it licked.

Has anyone here heard of anyone trying pneumatics for home theater control? The way I see it, it would be perfect for projector lifts, curtians, masking, basically everything. The only downside is the supply line. If my logic is wrong, let me know before I jump in with both feet.

Luke

Sounds like overkill to me, but, no I can't see why it won't work :)

Mark

Sounds like overkill to me as well. Linear actuators are fairly cheap and don't need air lines. For longer throw needs, a motor and a spool work well.

There are a few things to keep in mind when using pneumatics. First, the force required. I suggest using a double acting cylinder, as opposed to a spring return single acting device as you will then have near full rated power in each direction. Second, you must make sure that the cylinder does not fire too quickly as it will come to an ugly stop at the end of the run. With a double acting cylinder, a four way solenoid will be required. This will typically have 5 ports - 1 for the supply hose from the compressed air source, 2 output ports (one for each side of the cylinder),and two exhaust ports (again, one for each side of the cylinder). Use speed muffler controls on the exhaust ports to control the speed. These have a pin valve which you screw in and lock at the appropriate speed. An additional feature to order on the cylinder is internal rubber stops to dampen noise at the end of the run, and improve the lifespan of the cylinder. Check out www.stcvalve.com for supplies, or www.aircylindersidirect.com

Thanks for the comments byellin, What you have suggested is exactly what I am looking at. Different source. I have not seen the rubber stopper, but I was planning on mounting some sort of rubber stopper at each end of travel to stop it. I will let you all know how it goes.

Luke

You might also want to consider a very simple X-10 IR trigger for the 120V solenoid. They work from standard remote protocols. Then you won't need a switch on the wall, just use IR from your programmable remote. X-10 stuff is just a control box that plugs into an outlet, and a very simple IR receiver to send the code on your house wiring. ON/OFF is all you need. A light controller will do it.

I got the basic actuator working in my garage today. With the speed control, I can limit the travel speed to anyting I want and control the force from between 0 @ 0psi, up to 35lbs of force @ 100psi. I seems very smooth and slick. The only problem is the 4 way solinoid valve that I purchased is designed for hydraulic, and passes air slightly. It works well enough to function test, but I need to buy a fit for purpose pneumatic solinoid valve. I haven't looked into remote control of the solinoid yet, I am just plugging an old extention cord into the wall to test.

Luke