View Full Version : Having trouble with pneumatic prop...

08-21-2008, 11:31 AM
I ordered the small-pop up from frightprops.com and bought a 17 gallon 150psi compressor at lowes last night. Started trying to hook it all up today and it didnt seem like it had enough power to go up, even when I set it to 145psi. Doug at frightprops said that 135psi would do just fine, but it didnt. I did have a mask and small foam torso on the prop when I tried this, but even when I took it off the bars only moved alittle bit.

Any Ideas?


08-21-2008, 12:17 PM
Is there a flow control valve somewhere in the line? If so it may need to be opened more.

The valve looks like this http://www.gearseds.com/curriculum/images/figures/flow_valve.jpg

08-21-2008, 12:48 PM
135 PSI! That's crazy. I have never built a prop that operates over 60, and my 8' animatronic http://evilusions.com/shop/product_info.php?cPath=22_181&products_id=1067 runs at 45 psi.

I agree, there should be flow controls either on the solenoid valve, or mounted on the cylinder, that will probably need adjusted out to allow the air to flow fast enough to move the cylinder. Once it moves at the speed desired, reduce the psi to the lowest setting you can, it will reduce wear and tear on your prop, and your air compressor.

Jim Warfield
08-21-2008, 01:48 PM
I built a prop to lift me (210 pounds) straight up at a high rate of speed and it only took about 60 pounds of air pressure to do this.
The piston might have had a 3 inch diameter, this was the trick. The unit was originally designed to lift the elderly up out of a bathtub using mere faucet water under pressure probably never exceeding 100 max.
Always more than one way to do something.

Matt Marich
08-21-2008, 02:33 PM
What diameter air line are you feeding the prop with? You need the largest you can get to avoid pressure loss, also, try adding a small air tank at the point of the prop if the compressor is far away from it.

08-21-2008, 03:29 PM
This hose is 1/4 inch. I finally got it working with the mask and torso at about 60 psi..