# Controlling/timing Tombstone Head Popper



## marsh28 (Dec 2, 2010)

Next year I plan on buying some 3 axis skulls for an animated show. At certain times, I would like each of the skulls to pop up behind a tombstone and begin talking. When they are finished, I'd like the skulls to retract.

I know that the grave popper could be easily done with a wiper motor. However, I don't think a wiper motor would work here because it would be difficult to synchronize. Instead, I'm guessing I'd have to go with some type of pneumatic control. Does anyone have any suggestions?

Thanks ahead of time. And yes, I know its ridiculous to already be thinking about 2012 but I have a Halloween "problem."


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## Lunatic (Oct 3, 2006)

Hmmm, I'm not a pro using motors but I use several wiper motors running continuously. A wiper motor has a park feature that stops after one revolution but you would need a half a revolution. A step motor might work. There are some very knowledgeable members that will steer you in the right direction. Good luck!


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## Otaku (Dec 3, 2004)

What you need is a way to have the wiper motor rotate 180°. pause while the skull has his say, then rotate back to home position. There is a circuit available that can do this. I've been using one to open a coffin lid, pause while the corpse in the coffin screams, then close the lid. Let me know if I can help with this project.


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## marsh28 (Dec 2, 2010)

Otaku, what you're describing is exactly what I'm looking for. Do you have any more information on parts etc. for building the circuit you are talking about?


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## Otaku (Dec 3, 2004)

The board is available from Simple Circuit Boards, but I haven't sent Jeff (the owner) the latest mods. The changes are pretty easy to do - cut a couple of traces, solder in a few jumper wires. When you're done you have a board that will control the wiper motor and trigger an off-board audio device (ISD-type, like a Cow player board, or MP3 player). There are a few goodies that are needed to index and power the wiper motor (a 10A relay, a snap switch and some wiring and mounting hardware). The circuit runs on 12VDC.
You'd need one board for each of your skulls, and a way to sequentially trigger them. This can be done with a BS2, PicAxe other micro-controller. Triggering the motor controller board is via a relay that switches a 12VDC signal to the timer, this is the same 12VDC that is powering the board. A separate power supply is needed for the wiper motor, unless you plan to use 12VDC for the motor(s).

Here's video of the motor in action:
Wipermotordemo.mp4 video by Otaku1031 - Photobucket


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## halstaff (Nov 18, 2009)

This is a great solution. I built one of these last year and it has run perfectly for 6 nights, never missing a beat.


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## Otaku (Dec 3, 2004)

Good question, madmax. Since the lid swings almost horizontally the weight is probably less than 2 lbs. I have noticed that even with that low weight there is no overrun when the motor stops. I'm using a 5VDC, 5A supply on the motor, set at low speed. If you use a 12VDC wart, at either speed, you'll get much better power from the motor.


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## mroct31 (Nov 10, 2007)

Does the wiper motor, when running in park mode regularly, move 180° then stop or does it do a complete 360°?


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## Otaku (Dec 3, 2004)

I believe the way the park function works is that when enabled i.e. wipers are shut off, the motor will rotate from whatever position its in to the "home" location. This makes sense, given that the motor could be in any position when that happens. If the motor is already in the home location, it should do a 360° rotation and then shut off. Good for a quick up-down or out-in movement.


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## halstaff (Nov 18, 2009)

I'm just using a 5V power supply set on the low setting as well. You can see mine in action at about 45 seconds into my haunt video - http://www.youtube.com/user/halstaff?feature=mhee#p/u


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## Otaku (Dec 3, 2004)

Pretty much. Which version of the board are you looking at? I don't have the parts lists on this machine, but can get it to you on Monday. Best guess on the cost is around $20.


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## marsh28 (Dec 2, 2010)

Otaku, I think what you've described is what I'm looking for. However, the prop won't be on a timer and instead will be triggered by one of my LOR controllers. Would this change the set up at all?


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## Otaku (Dec 3, 2004)

Good question - I don't know how LOR triggers work. What is needed to trigger the board is a simple relay or other switch closure for about one second. However, that switch needs to be able to handle 12VDC. The board is designed to use its 12VDC source as the power that is used to charge the master RC timer. If LOR has the capability of switching hot contacts (AC or DC) then you should be OK.


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## danolan (Nov 30, 2011)

We did the head pop-up thing this year with a pneumatic cylinder. We used a 110V solenoid valve plugged into a DMX dimmer box and controlled it with DMX software. It doesn't talk but the effect was good.


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## Bascombe (May 18, 2010)

heck, I'm already thinking about 2014


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