bicycle pump actuator

[stempile]

My neighbor had a good setup for his Halloween display that used a bicycle pump for an actuator. Required a single action pump (only pumps on the down stroke (these are cheap)) hooked to an in landscape sprinkler valve ($5-10). The valve was hooked to his small garage compressor. I can't remember what the PSI was set at, maybe around 50. The actuator had enough force to quickly pop up a scary prop. The value was opened and closed via a switch between the power supply. This could easily be replaced with some kind of relay and control in concert with lights from Vixen. The valves are 12 or 24 volts and mostly standard.

[wjohn]

this would be an easy add on board for an Olsen 595 or a GRINCH. How many channels do you need?

[teberle]

I use Screen door closers with 110 volt 3 way pheumatic valves. The screen door closers are nice because they have a spring return and are easy to fabricate.

[lazz]

while screen door closers / bicycle pumps and the such do in fact work I can speak from experience they are dangerous...

in fact the very first air prop I build was with a bike pump .... it got stuck at 25 lbs of air pressure.. so I uped it to 50.... well it tore the lid off a large city trash can.... with such force it went sailing backwards in to my wifes car... well that dent wasnt one of the forgiven ones....


if anyone should want to try their hand at air powered stuff ebay is the place....
for under 25$ you can find a 110 soleniod and a small cylinder....


for example
http://cgi.ebay.com/Schrader-soleniod-valve-74304-8115_W0QQitemZ220116264130QQihZ012QQcategoryZ67011 QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

and
http://cgi.ebay.com/SET-OF-4-BIMBA-STAINLESS-D-35930-A-Air-Cylinder-magnet_W0QQitemZ290123113087QQihZ019QQcategoryZ109 498QQrdZ1QQcmdZViewItem




so folks while the other stuff is interesting... save your skin and use the real thing... it isnt all that expensive....

[teberle]

I agree. I only have one Halloween prop with a screen door closer but it is controlled with a pressure regulator. All of my other props are controlled by real pheumatic cylinders that I pick up from ebay.

[BuzzKill]

My set-up consists of 4 bike pumps. Dissasemble the pump and remove the check valve that keeps air going one-way to the hose. Each pump differs a little. So it make be a little different on each one.

I use only pumps with a built in gauge. Remove the gauge and use that screw fitting as the Air-In. Just grab a barbed fitting from the hardware store.

Cut the hose and attach a needle valve to a barbed fitting for the air to bleed off after actuation. So the air goes in the guage fitting, raises the handle and then the weight of the prop pushes the air back out the needle valve to reset itself. I also have micro switches and magnetic switches that I can use along the stroke to activate other parts of the prop. So as the air forces the handle up, it trips a micro switch to activate LED eye's and a voice chip connected to some speakers to say some spooky phrases.

I use lawn sprinker valves connected to a manifold made of schedule 40 PVC. 40 PSI is well under the PSI rating of Schedule 40 PVC pipe.
Off the valves is clear refrigerator ice water supply line, and press fit connectors for my props. This does a couple things for me. I can use low voltage. And it helps regulate the air flow from the main air tank so I don't get into a nasty over-pressure situation.

Pnuematics is not just pressure, but also supply. I can run 30 PSI through 20' of 1/4" hose and it will build slowly to raise the pump. By tweaking the needle bleed valve, I can make the handle rise quickly, or more slowly for the effect I need. Using 3/4" pipe right up to the pump and going to 30 PSI instantly, will just shoot the pump into orbit. We are building a prop, not a pumpkin chucker, or a potato gun. I want a handle that rises, not shoots a hole through my roof, or a visitor. It also leaks a lot of air so it sound creepy when it is all firing. I crank the regulator from my compressor down to about 30-40 PSI on a 7 gallon tank.

[ErnieHorning]

I can see using compressed air as a simple way to move an object. I can also see the potential danger.

Do you guys that use bicycle pumps use any safety assurance like screwing or welding the ends of the pump or maybe a safety chain? Air volume can be compressed a lot and expand very rapidly. I can see easily launching a light weight handle up over the neighbors house across the street, a bit like shooting an arrow straight up with the same potential result.

This is just a question and I don’t mean anything hostile. I’m just thinking of someone with little knowledge in this area, creating a serious situation out of something that started out as fun.

[BuzzKill]

Mine is in storage right now. Otherwise I would post a picture. I use an "L" bracket and a peice of aluminum rod to keep the handle from rotating. The rod slides up and down a small hollow tube that is attached to the outside of the pump. I have a safety wire that rides with the handle incase the top of the pump fails. But the pump can inflate a tire to 120 PSI. So I think my 35-40 PSI is just fine. Using the 1/4" tubing limits the "inrush" so I am not slamming the piston when it is actuated.

[BuzzKill]

Umm .. I missed the part about "creating a serious situation out of something fun" part of your post. I think the same thing when noobs come to this site and start messing with 120 volts on open boards stuffed under metal coffee cans in the snow. I don't think I have seen in all the photos ever posted a single NEMA rated, outdoor, weather, wet conditions, enclosure for the amount of current some of these displays use. I am amazed that nobody (to our knowledge) has been vaporized yet.

[Macrosill]

.....I think the same thing when noobs come to this site and start messing with 120 volts on open boards stuffed under metal coffee cans in the snow. I don't think I have seen in all the photos ever posted a single NEMA rated, outdoor, weather, wet conditions, enclosure for the amount of current some of these displays use. I am amazed that nobody (to our knowledge) has been vaporized yet.

Lets keep our fingers crossed!!!

[ErnieHorning]

Well, there is that one thing I wanted to add to my display…

http://img254.imageshack.us/img254/3730/tesla20coil1vm6.gif

[DynamoBen]

I guess you don't need extension cords anymore. ;)

[wjohn]

Well, there is that one thing I wanted to add to my display…

http://img254.imageshack.us/img254/3730/tesla20coil1vm6.gif

Holy Sh$T

[teberle]

I think that would look awesome in one of my Halloween displays!!!!!

[Greg in Canby]

I think that would look awesome in one of my Halloween displays!!!!!
Yea, I gotta get me one of those!

[TERBObob]

Building a JACOBS LADDER is easy ( that pic is just a modified version of that thingy that shoots jolts of electricty across two copper roads , like in the Frankenstein movies ...
Get yourself a starter from an oil burner ( ya know ... the kind that heats houses ) and simply use the output posts connected to two small copper ( solid ) wires angled at a V shape . ( spread out further upwards after the connections at the bottom )
Now , add the juice ( electricity ) to the transformer and wha-la ...
Now ... this next sentence is VERY important !
This CAN kill you if you touch it ! ! !
let me repeat ....
This CAN kill you , if you touch it !
I made two of these for my Halloween display and BOTH are in plexiglass enclosures and not within ANYBODYS reach . One , is located inside my house , in an upstairs window , viewable ONLY from the outside to the folks OUTSIDE .
The other is inside a shed that is also NOT acessable to the public , but is viewable to them via a 3'X3' window .
Now , about the bicycle pump ... first , there are MANY options that are NOT listed here .
First ... PVC is rated higher than your bicycle pump for pressure . And , I use and make my own ( that way , you can make the throw and long as you like , or as short , and also as thick for strength .
Next , your household washer machines have a solenoid in them for WATER control . To turn ON and OFF the water as needed . These are rated at 110 volts and are a VERY choice to use for turning on/off the air to your control .
I set my air compressor regulator at a max of 50 PSI and have NOT had a single problem . I have been doing animatronics Halloween displays for approx 10 years now and NEVER had ANY kind of situations as stated above .
When using this , I also utilize counter controls ... if the display I am appling air to lift is light , then I use an added spring t slow it down ( rather than add a regulator to each display ) and if its too heavy , I simply add a spring to add in the lift - just make sure it is not too strong , otherwise , the display will not return to its normal postion .
I air-power numerous items ...
A hand that is attached to a corpse that is lying down next to a headstone that reaches out to "getcha" . Another to raise and lower a coffin lid ( which also acitivates the fogger machine inside , which also turns on the UV lighting , and UV lighting on the FOG looks REALLY eeary ..
I also have on that activates a gruesome looking fellow who is sitting in a chair and "rises" to the occasion , when acitvated .
And a witch for stirring her pot/cauldron , a giant spider that is on the lawn .
And also utilze RC controls for numeorus items . I have Dracula standing at the entrance to my sidewalk ( from of house yard ) that is strickly RC controlled with a baby monitor enclosed so I can hear what floks say and use the RC servos to turn and lower Draculas head to adjust so he is looking right at a particular person and address them . I have a simple PA setup with a speaker enclosed inside his neck so I can verbally respond to the folks walking past . I have numeorus other animated displays for Halloween as well .
I am just getting into trying to utilize this for my Christmas items . ( not as easy . )

[DynamoBen]

I've seen numerous plans for PVC cylinders, how do you build yours?

[tommy]

I made a Jacobs's Ladder over 30 years ago when I was in college. I used a neon transformer to generate the high voltage necessary. The secondary of the transformer was 15,000 volts, so it would throw a pretty good spark. I only got zapped a few times, but the shock wasn't any worse than what you would get from walking on carpet and then touching a doorknob. I'd bet that I still have that Jacobs Ladder around here someplace.

tommy

[awhaley]

Hey all, I was browsing outside my usual spots on the forum today and read through this thread... I know it's generally bad form to respond to things months later, but since this is still the most recent thread in the section, forgive me!

I just wanted to weigh in what I know about the (interestingly off-topic... I'm breaking two rules of etiquette at once!) high voltage electric gizmos that were being discussed, in case any of you really ARE thinking about putting them in the displays this haloween....

What Ernie posted a picture of isn't a jacob's ladder at all, it's a tesla coil. A tesla coil is a sort of two stage high voltage transformer that operates at a very high frequency... I'll explain:

The first stage is often a neon sign transformer, or other over the counter transformer designed to take 120V AC and give you something in the range of 15,000V at low current.

The output of this transformer is fed into a large homemade capacitor (a lasagna made up of layers of glass and foil, with a motor oil sauce poured liberally over it is the recipe I remember...).

The Capacitor discharges across a spark gap. This is just what it sounds like, a gap which the electricity arcs across when the charge on the capacitor reaches a certain point. Usually this gap is adjustable, so you can regulate how frequently and with how much charge the cap discharges... This cap discharges something like 2000 times per second, if memory serves correctly, which means the output sends around 16 pulses per half wave of the AC cycle, so it's actually giving the secondary transformer a sorta pulse DC that happens to change polarity 60 times per second....

The second stage transformer is a homewound contraption in the 1:1000 range, which takes the high voltage, high frequency pulses and spits out INCREDIBLY HIGH VOLTAGE (in the MILLIONS of volts range) electricity, which displays as a big ball of lightning at the top of the second stage transformer.

Safety wise, there are plenty of ways to kill yourself with the contraption, between the 110Vs you're plugged into, the 15kv at the end of the first stage, the big cap, the flamable fluid IN the big cap, the spark gap, etc... but the actual lighting storm is of such a quality that it's not all THAT deadly.... its a voltage and frequency combination that I'm told passes on the surface of the skin, so it doesn't have the strong chance of stopping your heart that a cross the body shock does at 110v... The arc is still super HOT though, so it can burn if it arcs directly to you. But I saw a man attract the lightning to himself using a metal rod, and he claimed he felt nothing. He also used it to light flourescent tubes from several feet away, and to shoot down paper airplanes and balloons.

A jacob's ladder is just two bare wires in a sort of rabbit ears arrangement over a 10000-20000V transformer, where they almost touch at one point then diverge as they go up. The arc starts at the narrow part, then climbs up until it breaks at the top, at which point the arc restarts at the bottom. The transformer for this is often the 15000V neon sign transformer that provides the first stage of a tesla coil, but this is the only real relation between the devices (other than the fact that they're both ways to make an open-air visible arc.) This transformer is plenty dangerous, and the electrodes are usually located at the end of cute ceramic insulators that make great handles to pick it up, and to latch onto if you start to pick it up and find it wasn't disconnected from power first... and this shock WILL travel through the body, not across the surface... so be warned.

All of this is vague for two reasons - it's been years since I've played with either device, and I don't want you building one just from my discussion... but go read up on it if you're interested. I just figured there are enough mad scientists here that someone might enjoy a little crazy electrical theory!

Merry Christmas everyone!

Art

[Greg Young]

Art, you must have built the same Tesla coil I did back in the late 1960's from plans in Popular Science was it??
A 48 inch secondary coil, 4 inches in diameter wound with bell wire (I forget the gauge). The caps were 18 inch square window glass, 4 in total with 14 inch square aluminum foil on each side.
It was certainly not pretty, but it worked!
It was not used much as it blanked TV and radio reception down a good part of my block, which made me not too popular with folks (those were the days of rabbit ears, etc.... that was pre-cable/satellite for you younger folks!;))
I still remember the smell of ozone due to the primary gap...
Greg

[awhaley]

Lol... I believe those WERE the plans I was given. :) They are amazing inventions. Tesla really had to be the coolest guy in the world, if you could get him drunk at a barbecue and gave him a ball of wire and a couple of hairpins....

Art