# Help making pop up Spitting prop with window washer



## whitehotdog (Jul 16, 2011)

Hi
I'm wanting to make a prop that raises a barrel and spits a jet of water .
I live in uk so too expensive to buy this in us and ship what with import duty ect .so going for d.i.y
I'm using a wiper motor to lift the head and that works fine but don't know how to get it to spit only when it pops up.ive ordered a wiper washer motor as suggested .but so far I'm stumped !
Ii know people use phuematics but have never used them so prefer the washer motor method .. 
Any help please guys.
Thanks


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## tstraub (Feb 26, 2012)

What are you using to run the wiper motor? Are you triggering the prop in some way or does it run constantly? do you have any pictures of the setup you have so far?


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## whitehotdog (Jul 16, 2011)

Hi 
Thanks for reply .i built the grave popper using instructions found on here .i think they are all basically the same principle .i wiper motor moves a long bar up and down thats connected to the prop head and the bar is supported by a wooden frame to keep head straight .i run this using a old laptop ac adaptor .i have in my mind some kind on switch that that the bar can catch on the way up to spray a few seconds and switch off when it catches on way down again .i don't know if this is possible but that's the general idea.


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## corey872 (Jan 10, 2010)

That would be my thought, too. Either have the raising motion trigger a momentary limit switch, so you get a bit of 'spit' at the top of the stroke. Or if you want to go really basic, just have a couple of metal tabs (copper, brass, steel, etc) which touch together at the appropriate point of the stroke. That would make a spit, then when the prop retracts, the metal bits pull apart and stop spitting.


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## ScaryLane (Jun 3, 2013)

I added Spitting to a jumping spider prop by taking a part a motorize supper soaker water gun. It had about the right amount of spit and work well if you very clean water. (No dirt.) It lasted most of the night on one gallon of water.


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## whitehotdog (Jul 16, 2011)

Thanks or the ideas guys a motion trigger should do the job.


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## mkozik1 (Sep 6, 2010)

Use one of tstraub's 4-channel programmable controller and record the movements from there. Hold down the 1 button to allow the wiper motor to move to the highest point of rotation and then let go, press the 2 button a few times for the spitting action, press and hold 1 button moving the motor to the very bottom position of rotation thus having the prop at it's lowest position. 

Nice thing is this has an MP3 player built on board and allows for ambient sounds as well as triggered sounds for when the prop moves. Nice board, take a look.


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## Otaku (Dec 3, 2004)

mkozik1 said:


> Use one of tstraub's 4-channel programmable controller and record the movements from there. Hold down the 1 button to allow the wiper motor to move to the highest point of rotation and then let go, press the 2 button a few times for the spitting action, press and hold 1 button moving the motor to the very bottom position of rotation thus having the prop at it's lowest position.


The only issue I can see with this method is that the board doesn't really know what position the motor is in, it just knows how long to apply power to it. Wiper motors are notorious for over- and under-running on timed rotations, sooner or later you get out of sync. You really need index switches to locate the high and low positions. I don't know if the above-mentioned board can accept switch-closure feedback or not, but if it can you can mount microswitches in the prop and send a high or low signal back to the board to start or stop the rotation.


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