# Ideas for Safey Coffin Bell Ringer



## bikerglen (Feb 1, 2017)

I'd like to build a safety coffin with a bell that rings periodically for Halloween next year. I like the looks of the prop in the upper left corner of this page (sorry for the link to pinterest):



__ https://www.pinterest.com/pin/610660030699998174/

I'd place it next to a tombstone. Anyway, I have a few ideas for how to make it work but I don't want to re-invent something if somebody here has already done it before. So...

Has anyone here built something like this before?

Anyone have a source for a similar bell?
Anyone have any ideas on how to link the ringer to a pneumatic cylinder or motor?

I was thinking a pneumatic cylinder could be embedded vertically inside the post then the rope tied to the end to strike the bell but I wonder if the bell and ringer would be heavy enough to pull the rope back out of the post after each cycle?

Thanks in advance.

-Glen


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## Cephus (Sep 10, 2018)

It should be very easy to do. Any motor should work. Just tie a line from the clapper to the end of a slowly rotating arm. It will pull the clapper to one side and then let go. Just use a prop controller to change the speed and duration.


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## corey872 (Jan 10, 2010)

If starting from scratch, as Cephus suggests, it would be much simpler to go with an electric motor. Just pop on an eccentric crank to yank the bell rope with each revolution and set up what ever trigger or random ringing you want.

if you go the air cylinder route, you not only need the cylinder (preferably double acting), but a couple solenoids, pipes, hoses, compressor, some sort of actuator, plus dealing with the "P-S-H-H-H-H-T-t" "P-S-H-H-H-H-H-T-T" each time the cylinder operates. Though if you already have many of those components, it could be made to work.

As far as finding a bell, ebay would probably be the 'go to' source. Might even find a real coffin bell on there.


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## bikerglen (Feb 1, 2017)

Thanks, all. I'll look into using an electric motor with an eccentric crank and start checking eBay for a suitable bell. I'd been looking at Amazon and Home Depot but didn't see anything too interesting.


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## Hippie Crane (Sep 17, 2019)

corey872 said:


> If starting from scratch, as Cephus suggests, it would be much simpler to go with an electric motor. Just pop on an eccentric crank to yank the bell rope with each revolution and set up what ever trigger or random ringing you want.
> 
> if you go the air cylinder route, you not only need the cylinder (preferably double acting), but a couple solenoids, pipes, hoses, compressor, some sort of actuator, plus dealing with the "P-S-H-H-H-H-T-t" "P-S-H-H-H-H-H-T-T" each time the cylinder operates. Though if you already have many of those components, it could be made to work.
> 
> As far as finding a bell, ebay would probably be the 'go to' source. Might even find a real coffin bell on there.


The PSHHHHHT PSHHHHHT is not very hard to deal with if you have technical background. You just have make a muffler out of a PVC chamber and some hobby foam.


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## bikerglen (Feb 1, 2017)

I have some of the exhausts that fit in the valve housings so I can try those, try Hippie Crane's suggestion, or possibly locate the valve and exhausts away from the bell and grave.


I also think I found a suitable bell on eBay. We shall see when it gets here.


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## fontgeek (Jul 24, 2006)

Almost any small electric motor with a wheel on it, and have a string fastened to a hole in the wheel offset from the center so that every rotation of that wheel tugs the string. The faster the wheel rotates, the faster it rings. It could be set on a timer or motion sensor to trigger it.


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## bikerglen (Feb 1, 2017)

It's almost two years later and I finally solved the problem and finished my prop! I used a small RC hobby servo to move a lever arm back and forth that's tied to the string connected to the clapper inside the bell. 

I made a video the prop in action followed by a quick explanation and video of how it works:






Happy Halloween!

-Glen


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## MBrennan (Sep 22, 2008)

Now I've got to make one of these!😆
I think I'll use Mikojay's Octo-banger, but use only one channel. Have the PIR trigger and use a door lock solenoid to randomly "pull" the string on the bell.
Also, maybe add some audio like the Haunted Mansion's "Coffin Occupant" saying "let me out of here."
I'd better get busy!


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## bikerglen (Feb 1, 2017)

MBrennan said:


> Now I've got to make one of these!😆
> I think I'll use Mikojay's Octo-banger, but use only one channel. Have the PIR trigger and use a door lock solenoid to randomly "pull" the string on the bell.
> Also, maybe add some audio like the Haunted Mansion's "Coffin Occupant" saying "let me out of here."
> I'd better get busy!


Audio sounds like a great addition to the project!


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## Allen_Haunts (Jul 26, 2021)

That is really awesome! 

Did you do the programming yourself or was there program code out there you could download? Can we get the program code?

It really is nice. How well does it do in the weather?


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## bikerglen (Feb 1, 2017)

Allen_Haunts said:


> That is really awesome!
> 
> Did you do the programming yourself or was there program code out there you could download? Can we get the program code?
> 
> It really is nice. How well does it do in the weather?


Thanks! It's not weatherproof or waterproof but I think if I put a piece of gaffer's tape over the seam in the roof, it might keep most of it dry in light rain. Going to need good weather or for it to be cold enough that the snow doesn't melt on contact.

The code and all the design files are available on github:









GitHub - bikerglen/halloween-grave-bell


Contribute to bikerglen/halloween-grave-bell development by creating an account on GitHub.




github.com





I created a project on hackaday.io that shows the wood construction details:









Safety Coffin Grave Bell


This is a safety coffin grave bell Halloween prop. When unsuspecting trick-or-treaters walk past its ultrasonic rangefinder trigger, the bell rings to alert them to get the grave keeper because the recently deceased might not be so deceased after all. https://www.youtube.com/watch?v=E7tYGaNCkb4




hackaday.io





-Glen


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## Allen_Haunts (Jul 26, 2021)

bikerglen said:


> Thanks! It's not weatherproof or waterproof but I think if I put a piece of gaffer's tape over the seam in the roof, it might keep most of it dry in light rain. Going to need good weather or for it to be cold enough that the snow doesn't melt on contact.
> 
> The code and all the design files are available on github:
> 
> ...


Fantastic! I will go check them out. Thanks.

-Bill


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## MBrennan (Sep 22, 2008)

Yep - Had to make one!
I used a Octobanger with a PIR trigger to control a 12vdc door lock solenoid, that pulls the bell string.
Added audio and a 12vdc operated LED flame lantern for good measure.


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## bikerglen (Feb 1, 2017)

That's great! Love the lantern and audio!


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## mikkojay (Sep 15, 2014)

Great design, very well done!


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## MBrennan (Sep 22, 2008)

mikkojay said:


> Great design, very well done!


Gotta give credit where credit is due. Without your work on the Octobanger, none of my props would have come to life!
Huge thanks for up-ing the game!


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