Thread: Shorten an air cannon blast?

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Okay, so I procrastinated too long. I have an air cannon I built that is triggered with a hacked motion sensor. Unfortunately the motion sensor on test keeps the air on for about 8 seconds...way too long. With only 3 days until Halloween is there something I can get locally that will shorten the blast to a second or less?

Whats your air solenoid run on? AC or DC? How are you powering it?

This is a common problem, a lot of people want to do that with a hacked PIR. I sold 5 air cannons to pro haunts this year (all with manual triggers) and a first year haunt assumed these would have motion sensor triggers (not at THAT price I told them!). The problem with having a motion sensored trigger would be that now you have to have a controller of some sort to prevent a massive loss of air. One way to get around this is to use a QEV (quick exhaust valve), or also commonly referred to as a dump-valve. A QEV valve will allow an air tank to fill until the pressure coming in is removed. So basically you install your valve on the input side (it stays open) until the trigger goes off, which shuts the valve, and closes off the input, which allows the QEV valve to vent the air tank to the outside world. The difference here is that when your hacked PIR is activated, it CLOSES the valve on the input side (rather than the output side) and allows the dump-valve to activate. it actually creates a fairly nice buffer between scares...

Lordmax, it's ac powered with a hacked pir sensor. Skeletalremains, thanks for the info. That sounds like exactly what I'm looking for. Now the big question...where to find them locally? Obviously with 3 days until Halloween shipping is out of the question. Thanks again for the help!

Yes but he wants to get this done in 3 days. Thats all well and good but its not feasable for a 3 day job.

If you're ok with electronics you can try hacking the motion sensor board. Basically, whats happening is the sensor sees motion, and then turns on a relay for 8 seconds. Thats controlled by a timer. If you can find the resistor and capacitor controlling it you can shorten the time.

I'm guessing you're not an electronics whiz since you're asking what to do here, so, that being said... um... I can think of some electronic stuff to buy and build but thats not going to be easy... or cheap most likely...

The more I think about it, for a 3 day fix and being affordable I cant think of anything.