Thread: Beginner's Guide to Props and Pneumatics

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Awesome job on the tutorial explaining the air switches. Wish I'd seen it about 2 weeks ago, would have saved a LOT of other reading for bits here and pieces there. Thank you.

Connexion Developments LTD had a great listing of the schematic symbols for this kind of hardware. Very useful if trying to shop for things you don't know the industry term or name for. Or used to create standard schematic diagram for your idea that could be understood and built by someone else.
Note: I'm not suggesting your's was hard to read or understand.

No worries Bobby! Yeah I used to do a lot of 'techy' drawings using symbols, etc (and still do to some extent).... but I just figured that some people might appreciate the simpler approach to the diagram.

Soon I am really hoping to get a couple more good tutorials out there. A new haunt in the Dallas area just asked me to build them some air cannons, and I have been promising that tutorial for ages. Hopefully I can get a good how-to out of that and post it up here! I might try to make a video this time, giving more insight into how it works... making it easier for people to see how exactly it goes together.

To SkeletalRemains - Nicely done!

To YardHauntJunkie - You are correct in your assessment of the EZ-8 controller. I have used both the EZ-8 and the PicoBoo, and as you surmise, they are meant for different things. I used the PicoBoo for a TCT prop in conjunction with a Cowlacious sound board and it worked perfectly for that prop. I needed greater flexibility and power in a MIB prop that pushed 5 solenoids, a fog machine, a strobe light as well as sound. EFX-TEC also sells a sound board called the AP-16+. This board has twin, built-in 20 watt amps and plays WAV files from your SD card. It will also play a background track like the PicoBoo http://www.efx-tek.com/topics/ap-16.html

Is there anyway you could email me this so I can save it to my computer? taysmache@hotmail.com

This is awsome. Would you send me a copy also? met42@aol.com

The PDF's of this are in this thread a few pages back...top of page 3 I believe.

Hallow all and WOW!! I just love how timeless this thread (started in 2009) remains. Thanks for posting all the updates and encouraging us to re-visit the info. Helps us all get through these cold winter days and greases the mental wheels for more creepy plans in 2011! BOO!

Originally Posted by SkeletalRemains

The PDF's of this are in this thread a few pages back...top of page 3 I believe.

Thank you SkeletalRemains for shedding so much light on the mysteries of pneumatics. Your tutorial is excellent!

I`ve been using wiper motors and Shiatsu massagers in my home haunt for the past few years but there comes a time when ya just gotta step up to pneumatics and I`ve decided this is the year.

My main concern, at this point, is how to determine what cylinder length is needed for the job at hand.

For example : To bring a prop from the horizontal position to a 90 degrees vertical position (like a coffin jumper) what "stroke" length would be required of the cylinder? (I wish now I had not slept through those boring physics classes in school)

Just wondering if there`s a formula or a chart or something to help eliminate some trial and error.

Thanks again and keep up the good work!!

Hey FeelNecro,

You are not alone if you are experiencing that "lost" feeling sometimes when it comes to things like determining cylinder length, what PSI to use, how to attach the cylinder, how to orient, swivel, etc, on your props. This is a huge detractor for a lot of people, but don't let it discourage you! There are a lot of different ways to design a prop and make it work effectively.

You do kinda have to go back and revisit a few basic physics principles, but for the most part it is easy to figure it all out. Do a little research on first-class and third-class levers on the net, those are the most commonly used levers in haunt pneumatics.

A first-class-lever situates the fulcrum (pivot point) between the effort (cylinder action) and the resistance (prop). A good example of this is a see-saw. If you apply pressure to one end of the see-saw, and the fulcrum is in the middle, you will get equal reverse action on the opposite end of the see-saw (same force and distance travelled). If you move the fulcrum closer to the resistance, you have to move the see-saw much further on your end to get the opposite side to move a little bit. The difference here is that now you are creating much more force because you have traded distance for force (leverage). Now let's reverse that, move the fulcrum back closer to your side, and you only have to move your side of the see-saw a little bit, but with great force, and you get a lot more travel out of the opposite side (reversing the leverage).

Since pneumatic cylinders have all that nice power in a small package, using a fulcrum allows you to exchange some of that force for distance. If you play with the lever length and fulcrum location a bit, you can usually find that sweet spot that gives you the action you want (on the prop end), and also allows you use virtually any reasonable cylinder length.

A third-class-lever situates the effort between the fulcrum (pivot point) and the resistance (prop). This allows force in the middle of the lever to nearly double the distance at the resistance end. The closer you move the force to the fulcrum, the more travel you get on the resistance end, again trading force for distance (reversing leverage). Leverage makes all things easier as we know, but most haunt pneumatics rely on reversing leverage to take advantage of the massive force exerted by a cylinder.

I would love to include some drawings or photos but I just don't have time to make any right now. I might be able to come back later and illustrate this better. I hope this helps though!

If anyone has questions or needs to correct anything I have said please feel free to post!

Thanks,

Hey FeelNecro, let me grab a video I have floating around somewhere that illustrates just what you are asking. I will post it up here as soon as I find it. The prop lies down and sits up straight with arms extended when it comes up...