Compressed Air -Phantasmechanics
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1. http www phantasmechanics com air index html Haunting With Compressed Air Part 1 Updated 11 20 2007 Compressed air offers a number of advantages over electrical actuators for haunts and has accordingly been used for many decades in dark attractions The hiss of air accompanying a scare was a hallmark of the dark rides grew up with Utilizing compressed air is the most efficient method to produce sudden and startling kinetic effects It is safe to use on damp ground outdoors allows quick and powerful movements without the risk of blown fuses or overheating and allows for the relatively simple construction of devices that would be expensive or impossible to duplicate using other methods The amount of force generated at the output of an air actuator usually a piston and rod housed in a cylinder and connected to an object to be moved by even a modest amount of input pressure can be amazing If you ve never considered an air system because it seemed too daunting peruse this article and discover the basics It may be just what you re looking for The Basics The basics of compressed air power systems are not hard to understand A compressor feeds air into a holding tank much as a well pump feeds water into a reservoir Fortunately air is compressible unlike water and a lot of it can fit into a relatively small stout tank The tank is essential to the proper functioning of the system and the tank s pressure is always higher than the2. You can use the front threaded mounting point around the rod opening if you re push pulling a sliding object and the cylinder does not need to move to keep from binding Grainger carries a line of brackets and mounts for these Speedaire components just ask about them By the way the pivot mount for this cylinder is Grainger part 6W163 See the clevis not to be confused with Butt Head s best friend on the end of the rod This is one method of attaching the rod to the lever to be moved in the pivoting scenario It simply screws onto the threaded end of the rod Since the end of the rod is a standard sized thread you can easily construct your own custom bracket or clevis Just make sure it s sturdy enough for the task Remember you should not depend on the piston rod to carry a side load In other words dont hang a heavy object from the rod as if it were a fishing pole It s not designed for this and the bearing will eventually fail or the rod will bend I ve seen this rule violated in some expensive haunt props from big companies with the predictable result early failure Flow restrictors They restrict air flow in one direction only In other words air can flow freely in one direction but is restricted in the other On unidirectional units there is an arrow in the restricted direction so pay attention to it Note the directional arrows air flows _ the arrows but is restrictec ee Part 4A788 Part
3. watch the tank gauge and see how high the pressure rises before the motor shuts off If it starts getting uncomfortably close to the maximum rated pressure shut the unit down Does the relief valve act before the motor shuts off It should not If the motor does not shut off don t let the owner tell you that the relief valve will be sufficient you will need to replace the limit switch How much compressor power is enough for your haunt Unless you are running several complex animatronics or plan to have a large full motion dinosaur in your front yard a modest 1 2 to 1 horsepower compressor with a modest reservoir tank should be good enough An Alternative If you find that a compressor is out of your price range consider renting a large compressed air cylinder and regulator from a local compressed gasses company One should do you for Halloween if you have only a handful of effects that are fired infrequently it can last for days If you see the tank pressure falling off too quickly you can always cut down the frequency of effect activation and or rent another tank Your Setup Modest size cylinders draw very little air volume per firing Let s say your compressor s reservoir tank holds air at an average pressure of 80 P S I The regulator at its output could be set to 40 P S I and a small number downstream gadgets will happily sip from the reserve It is better in an aesthetic sense to fire effects separately and the price
4. 6ZC07 What are they used for Making an animatronic move at the proper speed for one thing Pop ups often reset as violently as they pop unless a flow restrictor is used on the exhaust cycle Sometimes one is needed on the activation as well Remember violent action is what kills props ahead of their time so here we have a means to avoid it Grainger has them as shown in the image above A lot of beginners confuse a restrictor with a regulator so let s look at the difference A regulator sets maximum pressure A flow restrictor allows the pressure to enter the line but more slowly than it would otherwise The line will eventually reach the full regulated pressure despite the presence of the restrictor Check valves Part 6D914 from Grainger is perfect for keeping full reservoirs from backfeeding that is losing pressure into the rest of the feeding system should it fail or fall low It has the same thread size as our 1 4 quickie connector but is male on both ends Use one on the inlet of any and all reservoir tanks you use As with flow restrictors be sure to look at the air flow direction on the case don t install it backwards Shut off valves ball type To begin with you may want one on your compressor just before the brass quick disconnect Also fit one or more with plastic QD s to provide yourself with a local shutoff for any given device Ball valves are positive washerless and tend not to fail They also require
5. Valve wae Exhaust Port Electrical connectors x2 Solenoid Out This is a good place to discuss the two basic valve types you will need The first is the valve mentioned and illustrated above Normally the valve connects the actuator to a small exhaust port in the valve that runs through the center of the solenoid When the valve is electrified via 24 Volts A C it connects the air supply to the actuator causing it to operate When off again the air is allowed to exhaust You can buy a connector socket for the solenoid part 2G505 if you wish It runs on either 12 V DC or 24 V AC The second basic type of valve is designed to operate a double acting pneumatic actuator These have inlets on both sides of the piston and thus they can be forced in both directions If you need to open and close a window or move a sliding panel for example this is what you need to use There s a separate exhaust port for each direction of travel on most of these too If you don t want to have air hissing in your scene you can pipe the exhaust outside the room with tubing See the image immediately below for an example The small red screw manually activates the valve when turned 1 4 turn clockwise Valve for controlling dual acting cylinders j This comes In very handy fo i Grainger 4XT32 This assembly comes set to operate at 24V DC or 48 V AC You need solenoid coil 4HN40 if you wish to operate it as 12V DC
6. acquire an electrically powered compressor Internal combustion motors are noisy and messy must be operated outdoors and will ruin the ambience of your haunt When you examine a used compressor give it a thorough going over How does it look Is it caked with gunk and garbage Is the intake filter attached to the pump black with residue Look for oil leaks at the pump assembly Does it look neglected or rusty If the tank has noticeable areas of rust on it forget buying that compressor A tank explosion is something you never want to experience outside of a movie Is there a user s manual detailing the maintenance and lubrication schedule Ask to see it If the owner has discarded the instructions this may be a sign of haphazard maintenance Is the electrical wiring in good shape Is insulation missing on any of the connecting wires or are any leads dangling Are there exposed connections or terminals You will need to correct any of these problems if you buy the unit Run the compressor and listen for rattles squeaks and other expensive noises Is it too loud for your taste Can you afford to install it so that it will not be heard throughout your haunt Stop the motor momentarily and listen Is there an excessive amount of hissing Are there leaks at the fittings on the tank itself Look for a label on the tank showing the rated pressure and make a note of it If this label is missing decline the purchase Re start the motor
7. of this is multiple solenoid electrical valves Consider adding an in line reservoir tank near each device just before the firing valves and you will not starve your effects for air You don t want to end up with a weakly presented startle effect Test all of your home brew devices with low pressures at first and gradually determine a safe working range Operate each effect such that it does not act violently enough to damage its own parts If one particular gadget is tearing itself apart add a small regulator to its input just before the valve Feed the device only as much air pressure as is required to produce the effect Door closers and bicycle pumps are not industrial parts and will wear out quickly if cycled constantly or with punishing force One correspondent admits to having produced a hole in his ceiling when an unfortunate bicycle tire pump blew apart under no load conditions while being tested for actuator use If you see water vapor squirting out of your actuators even with a filter present at the output of your compressor consider adding small filters near your effects and or consider locating the compressor in a low humidity air conditioned environment Problems with leakage are usually limited to noise and slight air loss causing compressors to have to cycle on more often I ve never been in a facility other than Disney s where compressed air devices were in use in which there wasn t at least a slight hissing pr
8. pressure required by any single device connected to it Attached to a fitting on the tank is a limit switch that shuts off the compressor when the tank has been filled to its highest safe pressure along with a spring loaded valve which releases excess pressure from the tank if the limit switch fails On the main outlet is an adjustable regulator which reduces the tank s pressure to that required by the connected system On this regulator are two gauges one reading tank pressure and the other showing output pressure The regulator setup may vary depending upon the size and cost of the equipment but it is essential to be able to read both tank pressure and the output pressure of the regulator The entire system we will describe is shown below SIMPLIFIED HAUNT AIR SYSTEM Manifold Compressor solenoid Local reservoir valves Main reservoir o9 Pirmary guages tank Air driven s ork animatronic Manifold block air horn etc op FORA ar blast nozzle t Solenoid valves og 4 a Pop up figure x Grave Jumper Local Pressure rated air hose regulator drier Air Filter and Trap Module The compressor s output line should be coupled with iret memes Exhaust a filter drier trap unit shown at right which is designed to remove oil and any foreign particles that 7 4 r may have been introduced by the compressor and is also intended to collect any water which condenses A Fiter out of the air a
9. sof e 20 2 bolt ae Lock washer just tight enough to apply firm force ee Ft ee Di B ae 70a Tight here If you ve built our Hitcher or CamDrive Floater kits you already know about these pivots A 1 4 coarse threaded bolt goes through the hole in the upright and is snugged down with a single nut and lockwasher as shown To make the pivoting element a flat washer is placed on each side of the arm that moves and is snugged down with a pair of nuts locked together In this device we ve added a lock washer to the pivot stack to apply some side thrust to eliminate as much wobble as possible Before assembling each pivot apply some automotive grease to the bolt and flat washers The top pivot shown here uses the single nut already secure on the upright as one stationary surface and a pair of locked nuts as the other surface To lock these nuts together snug down the first one until the arm can still pivot but is quite snug then while holding the first nut stationary with a wrench use a second wrench to lock the second against the first firmly When done the nuts should not move when you pivot the arm Be sure they are quite tight or they may work loose as the prop breaks itself in You should check for this as you test the prop before putting it in a display situation The lower joint formed on a 2 bolt as shown must allow the flat arm to clear the side of the pneumatic cylinder as shown Its pivot is locked wit
10. ed greater flexibility you can use Polyurethane tubing which can handle even more pressure 140 PSI Grainger has it it s 85 a roll in 1 4 4HL94 and 39 a roll in 1 8 4HL92 Stick with Nylon to save money on long straight runs Below are shown two sizes of inexpensive clear PVC hose that can be used if you don t need pressures higher than 45 PSI It comes in 100 rolls You will need 1 4 Grainger 4HL97 and 1 8 4HL96 AE Kuri Tec anantun om 1 8 cannot carry a large volume of air at once so it s better for slower moving gadgets 1 4 is better for faster heavier pop ups and for filling air cannon reservoirs that guzzle The Kit GAUGE FOR USE AT A PNEUMATIC _ e EFFECT _ FITTED FOR 1 8 LINES 1 4 QUICK CONNECT REGULATOR AND QUICKIE MANIFOLDS 1 8 QUICK CONNECT Let s start with a list of the rest of the parts needed for basic animatronic work Quick connect 1 4 on a metal quick connect fitting for connection to compressor This gets air to your first component and eventually the rest down the line 1 8 NPT can also be used but it will restrict your entire system The Grainger part numbers are 4HN10 1 8 and 4HN12 1 4 These two sizes should get you through your projects Larger sizes are available if you end up needing more volume The plastic quick disconnect fittings work like this you press down on the nylon ring around t
11. ent is connected to a branch the valve may be electrically activated for automation purposes A secondary regulator and in a large system a smaller filter trap may be required at this point Typically the actuator s feed pressure must be limited to a lower pressure than the higher feed pressure as this is usually higher than the actuator requires or can safely handle As described above actuators include cylinder piston assemblies but also include air turbines inflatable bladders and spray nozzles In the context of a haunted attraction you can move an object suddenly inflate a figure which materializes out of an enclosure in the blink of an eye cause an object or surface to vibrate or startle your guests with a blast of air When several closely proximal branches are required multiple tap connector blocks known as manifolds are employed These may optionally be equipped with manual or electric valves that control the flow of air to each output line individually Valved manifolds are useful for automating the movements of a device comprised of interacting actuators such as an animatronic figure When a manifold is used a main regulator may be placed at its input to control the overall pressure feeding the device along with other regulators at each actuator in the setup where necessary The master air storage tank at the compressor holds a surplus of air as a buffer Its pressure should not decrease significantly even if a numb
12. er of low pressure devices all fire at once At each device that requires a strong sustained surge when acting a small in line tank or reservoir spherical or cylindrical is installed such that extra air does not need to travel a long distance through a restricted line to reach it Unlike electricity air is slowed significantly when it must travel through long narrow conductors Without reservoirs actuators may work more slowly and unpredictably especially if they are triggered often or if several devices are triggered at once What does all this mean to the phantasmechanic Here are some tips on setting up your system Buying a Compressor NOTE A new generation of affordable compressors features oil free operation and typifies the offerings available at suppliers like Home Depot The principle advantage of this design is that it allows inexpensive construction but with the sacrifice of relatively quiet operation and long term reliability Be sure to discover whether you can live with the noise produced by these units before you buy We recommend that you look into compressors featuring the traditional oil filled crankcase if you intend to use air power in a commercial haunt If you are just beginning to experiment with air power recommend that you consider a used compressor as new ones can be rather expensive Shop garage sales and watch the want ads Call rental equipment stores and ask about purchasing a used unit Be sure to
13. esent Nevertheless you should try to limit this to a minimum as it is distracting and can warn your guests that something is about to happen Precautions The only real dangers in any air system come from 1 a poorly maintained compressor with a faulty relief valve 2 devices operated at excessive pressures which may cause them to self destruct sending parts flying and 3 bad connections at fittings which might allow a hose to come loose and knock someone senseless A loose and flying air hose especially one with a metal fitting attached to it can really present a hazard even at moderate pressures and the only way to stop it is to close the valve at the source Don t try to grab it You should have a master shutoff valve at your compressor s tank just in case Compressed Air Made Simple Part 2 A Pneumatic Tinker Toy Set for the Home Imagineer Updated 11 20 07 Note In this article part numbers from Grainger are supplied Please note that cheaper parts may be found elsewhere One source we recommend is Evilusions com They have most of the air components you will read about in this article and the next and at very reasonable prices Be sure to have a look Most beginners dread pneumatics because of the bewildering array of devices connectors and parts that require wiring to a power source and switching equipment Indeed if you begin putting together an animatronic device without doing some homework first you ll be callin
14. et a Pre Delay that is a period after triggering during which nothing happens This can allow more patrons to be close to the pop up when it goes off The On Time setting allows us to tell the unit how long we want the pop up to be seen The Off Time lets us specify how long the timer will rest before once again allowing a trigger The trigger is either a simple switch closure or a special accessory infrared detector provided with a special hookup For automatically repeating firings you d simply short these switch trigger contacts with a piece of wire If we re dropping a prop down we wire to the normally closed contact which applies voltage to the solenoid to allow the air pressure to hold our prop up in the air When the relay fires the valve goes to exhaust mode turns off and our prop drops Simple really Here s a complete pneumatic hookup for moving a bi directional cylinder 4XT32 set up to operate a dual acting cylinder with flow restriction T if When valve s active air feeds this end x at Tia In both cases the inletis n turned into an exhaust for the Ske end of the cylinder that is not taking in air lt Once again CAUTION Be careful when testing a cylinder under no load Use flow restrictors in both directions so it doesn t get slammed at the end of its travel It can also hurt YOU by stabbing or pinching Since we had to use over 50 PSI to make this valve work properly part of the valve i
15. g and driving all over the place wasting time and money Instead we offer you a method of selecting and connecting air components that is simple This chapter will cover the basics of these components and the upcoming chapters will go into detail about specific applications CAUTION You must develop a respect for the power of pneumatic actuators cylinders etc Even a low air pressure on a device can make it powerful enough to injure you When experimenting with air don t hook up to your main supply unless you are clear of the device and everything is safely positioned away from you Be sure your connectors are snugly fastened and will not fly apart Do not activate your electrical supply until everything is safely secured Stay by your shutoff valve just in case You have officially been warned now don t hurt yourself by being too eager Let s assume you ve bought a compressor and have tested it The output of your compressor should have a quick disconnect fitting attached to it It s a metal usually brass gadget that is universal for air tools Let s look for a moment at a typical oil sump compressor Fring ja author s rebuilt compressor running on a 3H P Harbor Freight PA Pressure d A A amp Valve za a R D inoue 2 Pressure Rh 9 y Switch nee i l heck Valv Unloader ron i wal ie This is my current setup rather underwhelming but it has all the parts it needs to be useful Let s s
16. gh 120 V valves are available A small one Grainger 3TZ67 about 8 9 will fire a few of these valves adequately For large numbers of valves get a larger unit Timers or show controllers More on this in an upcoming chapter but for now to set off a device you need a means of either detecting a passing guest or making the prop cycle repeatedly Both http www evilusions com and http nauntmasterproducts com have timers with and without passive infrared motion detectors just for this purpose To make a timer cycle endlessly you just hard wire the trigger input closed and adjust the knobs as show in the instructions Why not just a PIR Passive InfraRed detector or switch mat Because the effect needs to stay up long enough to be seen and it needs to be buffered from constant re triggering Timers provide this capability Here s a simple example circuit for those who want to try their hand at a finished pop up controller 24 V A C Transformer Solenoid Valve 110 V A C in Trigger Example Triggering a Pre Delay On Time Off Time simple pop up Inside the timer is a circuit controlling a relay which is nothing more than a switched switch Normally open means that until the timer is activated the switch is open or off When the timer activates the relay closes turns on and provides a completed circuit to the solenoid on the valve which then opens and the pop up jumps On this particular timer we can s
17. h a double pair of nuts as the photo makes clear Once again apply grease before assembling The opposite end with its 13 riser arm is completed exactly as this end The riser is tall enough for you to mount a wig stand on it over which a Halloween mask or other custom face may be placed There is also room for a pair of wire shoulder forms as with the shoulders of an FCG marionette and the 22 inch throw will allow for the average head and shoulders about 18 high to be completely hidden behind a tombstone Now it s time to talk about applying air to the device and triggering it We described the components shown below in part two so they should be familiar to you Transformer required Grainger 3TZ67 Pneumatic chain Grainger rains TANIS 20485 REAA Restrictor for pop up Grainger for Inlet vp fMAA7ES reset ds 1 i l Regulator VEIE DO NOT OMIT THESE Assemble your chain as shown in the images Tubing length may vary as needed but try to keep your flow restrictors as close to the pneumatic cylinder as possible while still leaving room for tube flexing and adjustment of the restrictors Note that the restrictors are arranged with their flow arrows in reverse to each other The one with the arrow pointing to the cylinder controls ascent and the other restricts speed of descent As mentioned in part two they don t regulate pressure but only control speed of flow Once you have your air chain assembled you
18. he tube and hold it then pull out the tubing It takes one or two tries to get the technique but once it s mastered quick disconnect air plumbing becomes much easier than wiring electricity Slide sleeve back to make or release coupling me _ am ea Manifolds one branch for each air effect you need to feed Fit all with appropriate quick disconnects The input to the manifold should always be as big as or preferably larger than the outlets Here s a good place to go from 1 4 to 1 8 as you begin to branch to your devices Notice the use of Teflon tape to seal metal to metal contact For you new air users Teflon tape is non sticky very thin white plastic that comes in rolls Home Depot Grainger wrap the tape about 5 6 times around the threads on the male part but you can use more The easiest method is to hold the part and turn it in the direction in which you would tighten it As you turn It feed the tape onto the threads Now screw the taped male thread into the threaded opening and use a pipe wrench to tighten it Please Note We no longer recommend the use of PVC plumbing pipe elements in compressed air setups If you have been using PVC please discontinue using it Although we have been using it in our shop for years without incident we have reliable reports that it becomes brittle with age when used with compressed air and may shatter under pressure We are converting the manifolds in our shop to black metal p
19. in the test with your current settings If necessary begin by adding slightly more regulator pressure not by opening the rising action restrictor Remember do not exceed 40 PSI Watch that weight A pressure between 20 and 30 PSI should work If the speed is still too slow then open the restrictor very slightly By all means avoid slamming the arm on the upstroke You will probably also need to further restrict the fall as well Keep testing until you get consistent safe action Now some advice on safety f you put this prop in a public area the public must not be allowed close to it or worse allowed to tamper with it What this means practically is that you must rope off the display and have a staffer on duty to observe crowd behavior As this is an unusual sight in a home haunt curiosity may draw the older visitors to snoop the mechanism so be on the lookout The best method of triggering a pop up is to do it yourself watching for the best opportunity for a scare This allows for the ultimate control of safety If you must use a passive IR switch some event timers we know of offer this option then make sure the prop is out of harm s way and that the Off Time knob has at least 10 or so seconds set on it to keep your prop from constantly bashing itself like a tire pump in action This also keeps the effect from becoming a bore and failing to scare anyone Have fun building and using your Grave Popper
20. ipe of the kind used in natural gas applications This is safe for use and we heartily recommend it The plastic quick disconnects we show are safe and this warning does not apply to them Regulators with 1 4 or 1 8 as needed NPT quick connects on in and out You will also need a filter trap module at the regulator on your compressor as mentioned above It keeps water and particles out of the other regulators and the actuators they feed Be sure to use gauges they re inexpensive on your regulators so you know what pressure you re feeding One example of a modular regulator is pictured near the beginning of this chapter Remember each device in a group of varied animatronics will most likely need a different pressure to operate properly so figure on one per device Complex animatronic devices will often need two or more of these so start small The regulator on your compressor should be used to regulate the maximum pressure required by the air hungriest effect Unless you re only running one effect avoid using the compressor regulator as a setting for the whole show Shop for price the best prices are at Harbor Freight followed by Home Depot Valves electric solenoid type fitted with 1 8 quick disconnects This little guy is fine for anything but an air cannon or monster pop up one that will return itself by weight to the starting position It has a small throat so it can t manage massive airflow 2G485 Single Acting
21. nd it will wear out prematurely Listen regularly for odd noises and stop the unit immediately if a loud and irregular noise occurs Keep kids away from the compressor and operating devices DO NOT run a compressor driven setup without someone home to supervise it Using Plastic Tubing for Pneumatics By using nylon pneumatic tubing and quick connectors to hook up your devices you will have a set of components that plug together as quickly as Tinker Toys This tubing can be cut with a razor knife to any length desired just be sure to make your cut clean and straight Remember the measurement given for this tubing is the inside dimension not the jacket and that is also true of the fittings and adaptors discussed below This is often confusing to first time air users but you ll soon get used to it For our purposes the easiest to find supplier for short lengths of this nylon tubing is Home Depot This tubing can safely handle up to 100 PSI more than you ll ever need for a haunt prop It s stiff and somewhat pricey about 4 for 25 of 1 4 but you ll need it The 1 8 seems only to be available in this ice maker plumbing kit which goes for about 5 50 6 00 it s about 43 cents a foot at Grainger and must be bought in 100 rolls 4HM08 That doesn t keep you from looking for it on the internet of course Nylon tubing is rather stiff and must not be bent too severely or it can kink and damage itself If you ne
22. need to install the event timer as shown at the right Make sure it is operating and that the valve is cycling before you apply air to the Popper More about the chain The regulator is the first active component The Popper will operate properly with 40 pounds of air or less so don t go beyond that pressure We ll come back to this in a bit but it s good to know it in advance 24 V A C Transformer Solenoid Valve 110 V A C in Normally Open Timer m O O O mang Triggering a simple pop up Pre Delay On Time Off Time Pay attention to the flow arrows on the regulator when hooking it up The arrow s should point toward the pneumatic cylinder on the Popper To begin testing adjust your regulator before connecting it to your compressor s master regulator to make sure that no air will flow initially Turn the adjusting knob counterclockwise until it stops This shuts it off The solenoid valve is also directional On the aluminum block with the fittings are some numbers 1 2 and 3 The inlet which connects to your regulator is 1 3 is the outlet which is normally closed when power is off and goes to the first flow restrictor For the record 2 refers to the tiny hole in the top of the solenoid assembly black case which exhausts the air when the valve turns off Begin your testing with no load on the Popper You ll add weight and repeat the test with your final working load later First go to your flow
23. only a quarter turn to open or shut and the handle shows the condition of the valve If the handle is in line with the tubing it s open If it s at a right angle to the flow it s shut See Harbor Freight or Home Depot for these at better prices Reservoir tanks these keep a large volume of air close to a hungry effect such as an air cannon You ll need to fit a check valve on the inlet so it won t back feed If it s going to be used to make an air cannon you ll need one with an opening of 1 2 to 1 diameter and a large throat valve to fit it We ll talk more about this in the next chapter Where does one get reservoirs Burned out oil less compressor tanks show up from time to time in household garbage and are often in good shape the user merely burned up the pump and ditched the tank as junk Make sure the drain valve on the bottom operates and that an ocean of rusty water doesn t come out when you open it Examine the outside of the tank for rust carefully and keep the working pressure down to about 45 PSI if you re uncertain of its interior condition Now it s a useful reservoir at least to you with as many as 3 or 4 inlets and or outlets You can also get small tanks intended to carry air for filling tires at Home Depot or Wal Mart and these can be refitted for use with a bit of plumbing work Low voltage 24 Volts A C transformer for valve solenoids For safety we recommend firing effects with low voltage althou
24. or 24 V AC Solenoid air valves aren t cheap this one costs about 62 plus a 12 lower voltage coil if you need it Note This particular valve requires a minimum of 50 PSI to operate Get one valve for every device or movement in your animatronic stable They also come in blocks A block is basically a manifold with valves on the outlets and they come in all varieties more in a later chapter If you want to do some homework on your own see the Grainger com catalog or website Pneumatic actuators cylinders These come in single and double acting varieties Singles have one inlet that pushes the piston and rod out the area above the piston is exhausted continually Double acting versions have been mentioned above You can obviously use a double as a single with the added advantage of being able to push the piston back to the bottom of the cylinder raising a prop that hangs down from above The prop will drop when the air is exhausted See the article on our Coordinate Ghost System CGS in the main index to view two such droppers A double acting example from Grainger is shown below with part number and suggested uses Grainger carries an assortment of piston diameters and rod lengths up to about 12 Apply air here to extend piston rod and here to retract it Front mounting threads Mounting these depends entirely on how they re used You can use the rear pivot if the entire cylinder must pivot to move a lever
25. restrictors and screw them fully clockwise Position the Popper so that it will not hit you or anything else so no one gets hurt and nothing gets damaged Remember using air under pressure is serious business Adjust your compressor s master regulator to deliver about 45 PSI Now connect your Popper regulator and after making sure that the timer is not firing dial up about 20 PSI by turning it clockwise slowly Now set the timer to give you about 5 seconds of on time and trigger it While it is triggered slowly open the Pop up flow restrictor just until the arm begins to rise Do not let it slam upward When the valve shuts carefully open the reset restrictor so that the arm falls slowly back down Again don t let it flop down hard Repeat your test until you are satisfied with the results If it is still too violent screw the restrictors down some If it s too slow do the reverse The Popper should rise to its full height in about 1 2 second or longer Much faster than this and wear becomes an issue over a long period It should fall back to rest even more slowly allow 3 or so seconds for a full reset If you ve even been in Haunted Mansion Orlando you know that the attic pop ups take their own good time in popping and resetting with good reason If your pop up rises within 1 second you still get the startle without undue wear on your pneumatic device Now it s time to add your prop head and shoulders for a full working test Beg
26. s actually moved by air pressure the reaction of an unloaded actuator can be quite violent Start with the restrictors screwed shut then open them cautiously until you get safe motion Remember though it s moving slowly now it still moves with considerable force and your hand cannot stop it We ll talk more about a specific application in the next chapter To Part 3 Building a finished Pop Up The Grave Popper Building a Pneumatic Pop Up Device The Grave Popper Shown below is the completed pop up with all the parts and sizes shown As usual with our props the material is 1 8 thick aluminum in flat and 90 degree angled 1 width It cuts with a hacksaw and drills easily with a hand drill If you ve ever shopped for a completed prop like this one you know that most examples are made of welded steel and are not at all inexpensive So how can we get away with using light weight aluminum By controlling the violence of the action using flow restrictors You will need two as you will see below or you will damage it and or yourself We re not kidding f you re still with us on this let s continue 1 4 hole leave 1 16 border between hole and the edge of the arm Grainger Mount cylender so that it is 6W163 perpendicular to base 1 thick base make it as large pn E rocks LA Sea as is practical for stability Cz In the above photo We ve identified the key parts you ll need from Grainger and will do
27. s it passes through As the pressure and temperature of the air drops when passing into this larger enclosure water vapor naturally passes Condensed Water into its liquid state Zz Water and debris including tiny metal particles shed by the compressor s mechanism contribute to rust corrosion and wear while oil causes deterioration in rubber parts and seals Thus a filter is very important for reliable system operation These devices consist of a perforated cylindrical part covered with a fine membrane housed inside a glass or plastic cup which is often covered with a mesh or cage to prevent injury to the operator in the event of shattering At the bottom of the glass is a tap valve which may be opened during operation to expel water and oil S Drain Valve The trap filter must capable of handling the highest pressure required by any device downstream They are typically rated for pressures between 100 and 200 P S I For our purposes this is more than adequate The unit should be checked regularly and the excess water must be bled off before it reaches the level of the filter In humid climates this can occur frequently if the trap is small As air lines run to multiple applications they branch by means of T connectors and valves on the main line The valves allow any single application to be shut off as needed allowing the system to continue operating If a single actuator a device converting air pressure to kinetic movem
28. so whenever the need arises in following illustrations The Stanley brackets shown come from Home Depot Begin by cutting the frame parts as shown and deilling the holes for the hardware The holes should be in the center of the face of the aluminum stock in other words the hole centers are 1 2 in from the edge All holes are 1 4 diameter The holes for the corner brackets are most easily drilled by clamping the brackets in place with a C clamp and then drilling right through the holes you can t miss this way Note that there are all sorts of extra holes in the pieces used but just ignore the empties We re used stock from previous experiments That hole for the pneumatic cylinder s clevis end is drilled within 1 16 of the edge of the arm so be careful with this one Note that when you install the pin through the clevis you ll need to insert the included cotter pin and expand it to secure the device in place Also when you isntall the cylinder arrange the pivot brackets on the base so that the cylinder stands perpendicular to the base it will tilt a bit as it moves the arm but not much The pivot brackets are separate one for each side of the pivot o e Tor a Detail of Base a Here s how the completed base should look with the upright and corner brackets installed You can see the pivot brackets screwed to the base in the left photo ve thel loose enough to pivot Lock tightly but together
29. tart at the pump and look at the unloader check valve This keeps the air in the tank from pushing its way back into the pump after it stops It also bleeds unloads the brass tube between it and the pump so that the pump can start easily There are basically two types of unloader this dual duty version and another that is fired by the pressure switch when the compressor shuts off the kind seen most often My rig was in pieces and rust powdered when got it so instead of going to the expense of adding a switch fired unloader got the combo version from Grainger On top of the unloader fitting is the pressure relief valve see tips below believe mine blows at 150 PSI Note the typical gauge pair tank pressure my pump stops at 120 PSI and regulator filter trap with gauge for settting the working pressure Note the water draincock at the bottom of the filter Out of sight under the belly of the tank is another water draincock All compressor rigs should have these parts in some form Compressor tips Drain the tank after each session of use Change the oil every few months of light use and immediately before and after October s show Use synthetic oil it s worth the extra cost and will keep your pump clean inside Check the pressure relief valve regularly just pull on the brass ring Push it back down to stop the loud exhaust Keep the belt modestly tightened It should flop just a bit while running Too tight a
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