This file is one of the Wolfstone archives of the Halloween mailing lists. You can find out more, and reach the entire collection here: http://www.pobox.com/~wolfstone/_r/HalloweenArchive.html This is a copy of Don Bertino's archive from http://www.calweb.com/~bertino/halloween.html on the subject of "compressed air". Minor changes have been made, mostly removal of E-mail headers and signatures, but the germane content is unchanged. - - Date: Thu, 29 Jun 1995 15:10:35 -0700 (PDT) From: Don Bertino Subject: Compressed Air Howdy! I have been thinking of adding compressed air to my halloween display this year. Has anyone else perfected it yet?? Using it to blow in people's faces.. From the ground up... Shooting heads into the air from behind tomestones... (aka Haunted Mansion) I am still trying to figure where to put the compressor so you can't hear it. - - From: dbell at cup.portal.com Subject: Re: Compressed Air Date: Thu, 29 Jun 95 15:53:36 PDT Don Bertino posted: >I have been thinking of adding compressed air to my halloween display this >year. Has anyone else perfected it yet?? >Using it to blow in people's faces.. From the ground up... >Shooting heads into the air from behind tomestones... (aka Haunted Mansion) >I am still trying to figure where to put the compressor so you can't hear it. Me too! I have been using CO2 for Dragon's Breath for several years, and have considered using it for propellant, as well. A *large* CO2 bottle only costs something like $30 to fill, and a few dollars a month, to rent. When you get the tank, you can specify whether you want a liquid delivery or gas delivery model - in the liquid delivery version, a dip tube reaches to the bottom of the tank. This is great for roaring, icy breath... For propellant, you would probably want dry gas. Another option would be Nitrogen. I'm not sure about the relative volume of gas at STP between a (liquid under pressure) CO2 tank and an equal sized N2 tank. The N2 is at a much higher pressure, but liquid CO2 is pretty dense. Let's see - at a guess, a 20 pound CO2 bottle might be about a third of a cubic foot, maybe 9 liters. Now, 20 pounds of CO2 is 207 moles of gas, and expands to 4600 l. 9 liters of N2 at 3000 psi, or 200 atmospheres, expands to 1800 l. Yep, CO2 is still better. - - From: alt at ixstar.att.com Date: Fri, 30 Jun 95 07:38:16 CDT Subject: Re: Compressed Air I have a compressor and tank in the garage which I use for (see Chris' Theme) operating 4 different devices. The first was what we refer to as the "pop ghost." It consists of a wire, about 18 gauge, stretched from the eve edge to a small stake in the ground. On the wire is an inverted plastic dring cup; you know, the cheap throw-away kind. It easily slides up and down the wire. Attached around the cup is a piece of white cloth making a little 1 foot ghost. At the bottom, anchored to the stake is an air solenoid feeding a small nozzle. When the solenoid is opened, the air blasts the ghost up the wire. The sound and the sudden movement is perfectly great. People love to be scared out of their minds on Halloween. The air line runs to 3 other devices which are actually pistons. I made the pistons from PVC pipe; 3/4" stationary pipe and a thinner piece of pipe as the piston rod. I used CPVC for the rod because its outside diameter is closer to the inside diameter of the PVC stationary pipe. It takes a lot of glueing and sanding to make the thing work; after which it leaks quite a bit, but it does work well. We use 1 to open a 6 foot coffin standing vertical. A second unit pops a skull out of an old whiskey barrel, and the third pops an ugly mask from behind a grave stone. The four air devices are controlled by us inside the living room with 4 switches in a little mini-box. - - Date: Wed, 5 Jul 1995 09:54:19 -0700 (PDT) From: Don Bertino Subject: Re: Compressed Air On 30 Jun 1995, Roy LeBlanc wrote: Hi Roy! > On (29 Jun 95) bertino at netcom.com wrote to Roy LeBlanc... > b > I have been thinking of adding compressed air to my halloween display > b > this year. Has anyone else perfected it yet?? > > An interesting effect you might want to try involves the 'blower' end > of a vacuum cleaner. It seems a light, round object along the lines of > a beach ball or ping pong ball will be suspended by a stream of air > set at an angle. > > o <--- ball > > / / > / / <--- exhaust pipe > / / > > Perhaps an inflatable skull might work, but I believe the effect depends > upon the aerodynamic effect of a sphere. Hey... I like it! I set one up for my son, using a lawn/leaf blower. Besides the noise. - - From: dbell at cup.portal.com Subject: Re: Compressed Air Lines: 36 Date: Wed, 5 Jul 95 11:20:31 PDT Hi, Don! So far, after a couple of years, I'm still using a manual valve - the one on the tank, to be exact. I've had no luck in locating a *cheap*, high pressure cryogenic valve... The valve needs to be able to handle 2000 psi safely, since the CO2 bottle can get up there, if it sits in the sun and the temp rises above the critical temp for liquid under gas. Normally, it runs about 520 psi (gauge). I also need as large an orifice as possible, so I can get a large flow of liquid to the expansion nozzle(s). Yes, I have one large tank, that I keep and reuse. Actually, the refill process is almost always a tank exchange, but since I only rent the tank, I don't really care. I run a length (5 or 10 feet) of high pressure hose I picked up surplus from the tank fitting up through the dragon's neck, branch to two 1/4" OD copper lines, and terminate in the mask's nostrils. An operator hides behind the scenery and twists the tank valve open for a "roar". If the system is used every few minutes, the flex line chills down (I could improve the time with better insulation), and stays near the temp needed to keep liquid present in the line during the flow. It takes a while, maube 10 seconds, to chill the line down from ambient. If I had a solenoid operated valve in the head, the long feed would stay under tank pressure, and liquid would (nearly) always be present a few inches back of the jets... As for use, I have a large tank (60" plus tall), and get *many* minutes of icy breath. I certainly get more than a party night and Halloween itself out of one fill. A fill is on the order of $30, and I keep the tank for a few dollars a month. - - From: alt at ixstar.att.com Date: Thu, 6 Jul 95 11:52:09 CDT Subject: Re: Compressed Air > On Fri, 30 Jun 1995 alt at ixstar.att.com wrote: > >>>Some stuff deleted to cut down on net glut! <<< > > > I have a compressor and tank in the garage which I use for (see Chris' Theme) > > operating 4 different devices. The first was what we refer to as the "pop > > ghost." It consists of a wire, about 18 gauge, stretched from the eve edge to > > a small stake in the ground. On the wire is an inverted plastic dring cup; you > > know, the cheap throw-away kind. It easily slides up and down the wire. > > > I have a problem with visulization from text, could you post some > diagrams to help, also are the devices electricly controled or > mechanically controlled. > I will post something with more detail in the next few days. The problem is, how to 'picture' it in a way all will understand. I will try to draw some ascii diagrams, etc. - - Date: Fri, 7 Jul 95 09:24:10 EDT From: mrc at cadre.com (Mike Caron) Subject: Re: Compressed Air From: alt at ixstar.att.com Original-From: alt at ixhale.uucp Date: Thu, 6 Jul 95 11:52:09 CDT Original-From: alt at ixhale.att.com (Arthur Louis Todesco +1 708 979 1120) Sender: owner-halloween-l at netcom.com Precedence: list > On Fri, 30 Jun 1995 alt at ixstar.att.com wrote: > >>>Some stuff deleted to cut down on net glut! <<< > > > I have a compressor and tank in the garage which I use for (see Chris' Theme) > > operating 4 different devices. The first was what we refer to as the "pop > > ghost." It consists of a wire, about 18 gauge, stretched from the eve edge to > > a small stake in the ground. On the wire is an inverted plastic dring cup; you > > know, the cheap throw-away kind. It easily slides up and down the wire. > > > I have a problem with visulization from text, could you post some > diagrams to help, also are the devices electricly controled or > mechanically controlled. > I will post something with more detail in the next few days. The problem is, how to 'picture' it in a way all will understand. I will try to draw some ascii diagrams, etc. Good luck. I LOVE drawing circles in ASCII characters ;)>. I would hate for people to take on the extra burden of trying to draw as well as describe textually their ideas. I think this will diminish the exchange of ideas. I sympathize with the poster that sometimes it is difficult to understand things without a picture (a picture is worth a thousand words), however, until this medium can support sketches I think it is a great burden to expect people to provide more than textual descriptions. (BTW, this is my opinion and you know what they say about opinions) - - From: dbell at cup.portal.com Subject: Re: Compressed Air Lines: 36 Date: Wed, 5 Jul 95 11:20:31 PDT Hi, Don! So far, after a couple of years, I'm still using a manual valve - the one on the tank, to be exact. I've had no luck in locating a *cheap*, high pressure cryogenic valve... The valve needs to be able to handle 2000 psi safely, since the CO2 bottle can get up there, if it sits in the sun and the temp rises above the critical temp for liquid under gas. Normally, it runs about 520 psi (gauge). I also need as large an orifice as possible, so I can get a large flow of liquid to the expansion nozzle(s). Yes, I have one large tank, that I keep and reuse. Actually, the refill process is almost always a tank exchange, but since I only rent the tank, I don't really care. I run a length (5 or 10 feet) of high pressure hose I picked up surplus from the tank fitting up through the dragon's neck, branch to two 1/4" OD copper lines, and terminate in the mask's nostrils. An operator hides behind the scenery and twists the tank valve open for a "roar". If the system is used every few minutes, the flex line chills down (I could improve the time with better insulation), and stays near the temp needed to keep liquid present in the line during the flow. It takes a while, maube 10 seconds, to chill the line down from ambient. If I had a solenoid operated valve in the head, the long feed would stay under tank pressure, and liquid would (nearly) always be present a few inches back of the jets... As for use, I have a large tank (60" plus tall), and get *many* minutes of icy breath. I certainly get more than a party night and Halloween itself out of one fill. A fill is on the order of $30, and I keep the tank for a few dollars a month. - - From: alt at ixstar.att.com Date: Wed, 19 Jul 95 15:33:07 CDT Subject: Using compressed air Ok, I have given this some thought and you're right it's difficult to explain in text. I use 4 air operated devices. Each device uses a 110 volt solenoid to turn on the air. Each solenoid is wired to a normal male 2-prong house plug. The control box is a homemade minibox with 4 miniature toggle switches. The cable from the control box is wired to a 4 outlet electrical box. There is also a line cord from the electrical box to get 110 volts. Each of the 4 switches turns on one of the 4 outlets. The outlet box is set outside and the control box wire is routed into the command center otherwise know as the livingroom. "Pay no attention to the man (or women) behing the curtains." See the ascii "schetch" at the end of this posting; it should complement the text. The simplest of the devices is what we refer to as the "pop ghost." It consists of an inverted "throw-away" plastic cup with an 1/8" hole in the bottom (now the top). A 16 gauge solid steel wire (bailing wire) goes from a stake in the ground to an eye hook in the eve overhang so that the wire is perpendicular to the ground. I also have a small turnbuckle near the top of the wire so that it can be pulled tight. The cup can easily slide up and down the wire. A piece of white cloth about 1' in diameter is over the cup; with the wire also passing through the center of the cloth. The cloth is glued to the flat bottom (now top) of the plastic cup. A 110 volt AC solenoid is positioned at the base stake to blow air into the cup. I found that a small hole for the air works best. I fabricated a nozzle using some small brass fittings; I soldered a small tube into the fitting to give a nozzle I.D. of about 1/16". The solenoid and nozzle are bailing wired to the ground stake and positioned to blow into the cup. I put a piece of foam rubber around the nozzle to prevent the cup from slamming down on the stake or nozzle. When the solenoid is opened, the cup (ghost) flies up the wire. Some steel wool or Scotch Bright makes the wire smoother so that the cup can slide easier. The flapping white cloth and the noise of the air is sure to scare everyone. We have moved it around from year to year so that repeat visitors can also be scared; kids love it, adults love it. As far as the other 3 air operated units, all were piston operated. I built the pistons from plastic pipe. They take a lot of fussing and fitting, sanding, etc. Below is a diagram of the pop-up skull. I use this same design to pop up anything, a bloody hand, a scarry head, and I even use this piston to open a large 6' upright coffin door. The piston rod is made from 1/2" CPVC pipe because it's O.D. is close to the I.D. of 3/4" PVC pipe. The "collars" shown are fabricated from regular 1/2" PVC pipe with their diameters custom sized to make tolerances "close" as possible. I used a sanding disk mounted to a 10" table saw to reduce the O.D. of the 1/2" PVC to make it fit snuggly into the 3/4" stationary column. The collar is then glued with the standard PVC cement inside the top end of the 3/4" stationary tube. The inside diameter of 1/2" PVC is carved away with a rotary file in an electric drill to allow the piston (1/2" CPVC) to slide smoothly inside. Similarly, another collar is fabricated and glued to the bottom end of the piston. This time the I.D. of the collar is snuggly fitted and glued to the bottom of the piston and the O.D. of the collar is reduced to allow it to smoothly slide inside of the stationary column. You then install the piston from the bottom of the stationary column before gluing the stationary column to the T. The piston should slide up and down easily; you can use some silicon spray and/or powdered graphite to help. I mounted a ring of felt at the point where the two collars come together to cut down on noise and soften the blow to the parts. The solenoid can be a very small, low volume unit. A clamp on the air hose between the solenoid to the T is used to regulate the air flow, and thus the speed of the piston; to much air and the whole thing would probably blow apart. On my "skull in the wooden barrel" the flow is fairly high to make him jump up pretty fast. On another unit, a stuffed mask slowly rises from behing a grave stone. I realize that this piston units leak quite a bit, however, they are cheap and they really do work. POP-GHOST: ______________________ | O Screw-in eye-hook in eve | { } { } Turnbuckle { } | --- / | \ Cup (ghost material not shown) / | \ half way up guide wire | nozzle^ | __|_|_ solenoid| | | Stake in ground | | | --------------------------- POP-UP SKULL IN BARREL (barrel not shown): /////////// __________ / \ 6| O O |9 | 7 | scarry head or | | something of the like \ mmmm / \______/ | | glued-in collar || || | | 1/2" CPVC plastic pipe as sanded to fit | | | | long as required CPVC piston | | | | | | | | 3/4" PVC | | | | stationary | | | | column as | | || || glued-on collar sanded to long as | | || || fit snuggly into 3/4" stationary required | | column at left. | | |______| pinch clamp on hose | | to regulate flow ___| |___ | ____________ ---| |____v________________| 110 volt |_____ air plug | | std 3/4" PVC T |_____________________| solenoid |_____ source ---|________________| ^ plastic hose |____________| - - From: alt at ixstar.att.com Date: Fri, 21 Jul 95 07:30:04 CDT Subject: Re: Using compressed air >>also a line cord from the electrical box to get 110 volts. Each of the 4 >>switches turns on one of the 4 outlets. The outlet box is set outside and the > >This is great! I love the pop-ghost idea. I'm new to this so I hope you don't >mind if I ask a few questions. First, where did you get the solenoid to control >air and how much should I expect to pay? Second, do you use a common air >compressor for the air? If so I can probably figure out the electric hook-up and >I have an air compressor, all I need is a solenoid! (Well... and a wire, plastic >cup, and white cloth!) > >Have you ever tried to make the switch 'pressure sensitive'? So that the ghost >'pops' when someone steps on a switch plate? Just curious. > >Good Winds, >Bobby R. Originally I wanted to control all this stuff with sensors, either IR or pressure, however, it is fun to do manually. Also, you get to know exactly when is the best time for the best possible scare. One funny thing, the ghost used to be in a place right near a wide crack in the sidewalk; a perfect place to run wires and cover them with duct tape. Well, a lot of kid thought that the 6" wide duct tape was a switch, so they would, after knowing that the ghost was there, press the duct tape with their foot. Of course, I wouldn't pop it up. When they finally stated walking away, I would pop it, sometimes giving an extra surprise. Automatic sensors could not do that. - - From: alt at ixstar.att.com Date: Mon, 24 Jul 95 07:25:03 CDT Subject: Re: Using compressed air > Where the heck do you find a solenoid to control air? I checked around with out > much luck. Also how much does one cost. I'd love to do this! > Bobby R. I used an old dishwasher water solenoid for one. I bought on for about $16 for another. These worked real good on 60 or 70 PSI air pressure. Look on garbage night for people dumping old dishwashers and cloths washers; the water solenoids should work and the price is right. Also, American Science and Surplus here is Illinois has a little unit that I am told works well. It is rated at a low voltage DC, however, in order to open on 60 PSI you must "overdrive" it on the voltage. Because you don't leave it open for very long periods of time, this is OK and it won't overheat. - -