# Prop Idea...Not Sure How To Build



## MartyMoose (Nov 3, 2021)

New user to the forum and first time poster.
I'm looking to make a bedroom scene with a metal frame bed and a little girl sitting on the floor. I want to create arms coming out from under the bed and pulling her under the bed pretty fast. I would also need a way for this effect to reset itself in between guests. Any idea on how this can be done? The pull under the bed would have to be pretty quick, but the reset doesn't need to be. Has anyone tried this before? Thanks in advance.


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## corey872 (Jan 10, 2010)

Welcome to the forum. It does sound like a prop that could be quite intricate. I'll rattle off a few things that come to mind and let me know what your thoughts are there.

So to start off with you say you wan the pull under the bed to be fairly quick. That typically means either a compressed air cylinder or storing up energy in a spring... or a relatively big/powerful electric motor. Typically it would be based somewhat on what you already have either in the display or in spare parts laying around or what you're comfortable working with.

The next part is the 'reset'. I'm guessing that 'sitting' on the floor is sort of a general posture/position that is not compatible with 'pulled under the bed'? Meaning the girl may need to 'lay down' or 'flatten out' to fit under the bed? Not a problem for a 'one shot' deal, but may complicate things for the reset. A few different ways to attack that... first might just be to eliminate it. Any possibility the girl could be laying down/reading a book, so the laying down posture would just fit under the bed? Or possibly the girl could be made of foam/stuffing so the form would just squeeze down under the bed, but fluff back up once she came out? Another option might be some sort of inflatable in the size/shape you need. I could also see it done with a jointed armature which would just get knocked down when going under the bed, but then the reset might get complicated...how to repose the 'skeleton'? Small electric motors on board seems to get complicated really quickly. Possibly some sort of pull string - they way they have those dolls that clap/dance when you pull their string...maybe this one could sit up?

Finally on to control systems. What are you familiar with...arduino? octobanger? relays/timers? other? Seems like this will be a multi-step process with a fair amount of timing involved. The microprocessor control could help you get the timing 'ideal' or even vary it with some random intervals, though there is somewhat of a learning curve. Relays/timers would also work if you're more familiar with the electrical side vs programming.

Hope this helps.


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## MartyMoose (Nov 3, 2021)

corey872 said:


> Welcome to the forum. It does sound like a prop that could be quite intricate. I'll rattle off a few things that come to mind and let me know what your thoughts are there.
> 
> So to start off with you say you wan the pull under the bed to be fairly quick. That typically means either a compressed air cylinder or storing up energy in a spring... or a relatively big/powerful electric motor. Typically it would be based somewhat on what you already have either in the display or in spare parts laying around or what you're comfortable working with.
> 
> ...


Thanks for the quick reply.
I figured the reset would be the most difficult part. I may need to just lose that thought at this point and manually reset between guests. If we manually reset between guests, that also means that the room would likely need to be staffed the entire time, so everything could be manually triggered as well.
I would probably go with a pneumatic system to pull her under the bed.
My plan is to have her watching some type of video on the wall. Just after she gets pulled under the bed, the lights and video would blackout which would help cue the guests to move on.
I am not familiar with the listed control systems at this point. I've been working in the entertainment industry as a lighting director and programmer for 25+ years, so I am not afraid to try triggering via any sort of controller.
I will look into your suggestions. Thanks soo much for your insight. 
Long ago, for many years, I worked the technical side of Knott's Scary Farm. Since then, we have done some small, front yard haunts over the past few years, but now we want to expand into something more "elaborate."


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## corey872 (Jan 10, 2010)

No problem. Looking forward to seeing this develop more. Like I said, a lot of it is working with what you are familiar with, what you have access to and what you have laying around already. If you have more experience with control equipment on the pro side of things, then that might be something to explore. If you're more familiar with electrical/electronics vs air, then motors might be the way to go.

One thought I had - if the girl were kneeling, it might be possible that one motor at the knees could reset the pose. She could flatten out 'face first' when grabbed and slid under the bed, then when resetting the motor would move the thighs back up and the back joint could 'catch' at about a 90 degree angle. (if all that makes sense...if not, I could probably sketch it out, though that might be more scary than the actual prop! lol )


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## MartyMoose (Nov 3, 2021)

corey872 said:


> No problem. Looking forward to seeing this develop more. Like I said, a lot of it is working with what you are familiar with, what you have access to and what you have laying around already. If you have more experience with control equipment on the pro side of things, then that might be something to explore. If you're more familiar with electrical/electronics vs air, then motors might be the way to go.
> 
> One thought I had - if the girl were kneeling, it might be possible that one motor at the knees could reset the pose. She could flatten out 'face first' when grabbed and slid under the bed, then when resetting the motor would move the thighs back up and the back joint could 'catch' at about a 90 degree angle. (if all that makes sense...if not, I could probably sketch it out, though that might be more scary than the actual prop! lol )


That definitely makes sense about the kneeling girl. A lot of it will come down to cost vs functionality. I don't want this one prop to eat up all the budget. I would rather keep it more on the simple side and spend money all around...then make it more"advanced" over time.
I think if I go pneumatic I may be able to play with the speeds a little better. A quick pull under the bed, but also a slow reset of the motor...which could be two hands coming out from under the bed to grab her. So the reset of the motor could actually play into the scene. But I would still need to manually reset the doll in her position.
Have a great Thanksgiving.


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## Atticus Finch (Aug 16, 2021)

One thought on the reset. Say you have the girl hinged at the waist with a wire or something from her head attached to the bed. When you pull her under, the wire would go slack so she could lay flat but when you push her back out for the reset, the wire would go taut and lift her torso up to sitting position. You'd be relying on gravity to make her go flat so you would probably want the head to be weighted properly. If it happens fast enough, the force of hitting the bed might do it too but you have to make sure she's sturdy enough to take that.

Also, depending on the angle she'll be seen by your visitors, you could make the back of her very flat so that when she folds down there's more clearance. Just spitballing. Good luck!


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## MartyMoose (Nov 3, 2021)

Atticus Finch said:


> One thought on the reset. Say you have the girl hinged at the waist with a wire or something from her head attached to the bed. When you pull her under, the wire would go slack so she could lay flat but when you push her back out for the reset, the wire would go taut and lift her torso up to sitting position. You'd be relying on gravity to make her go flat so you would probably want the head to be weighted properly. If it happens fast enough, the force of hitting the bed might do it too but you have to make sure she's sturdy enough to take that.
> 
> Also, depending on the angle she'll be seen by your visitors, you could make the back of her very flat so that when she folds down there's more clearance. Just spitballing. Good luck!


That’s a good idea. Thanks for the advice. I will see how I can make this whole thing work.
I had someone tell me we could use a real girl and pull her under the bed. LOL. No way this could work out well for her doing this all night long.


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## DarkOne (Oct 16, 2012)

Will the hands come out from under the bed and grab her, or will they already be out when the visitors enter the room? 

If the hands come out and "grab" her, I think she would need to be on a track for reset. It could be built into a rug or carpet that she is sitting on. It will definitely be a challenge to design a doll that will go from sitting to lying with a reset. I think she'd need to be sitting with her thighs resting on her calves to make it "easier". As she is yanked back by the ankles I imagine the upper body falling forward with a joint at the hips that goes from a 80ish degree to a 180 degree "layed out" position. Hopefully she would fall flat before going under the bed. For reset, I think an attachment at the knees to push or pull her back out and then the cable idea attached at the lower back may reset her to the seated position.

This would be a fun project to even do a small model of. Can't wait to see what you come up with.


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## rottenorchardart (Dec 13, 2021)

sounds like a linear actuator. maybe even a pneumatic one pushes out real fast 


Amazon.com : high speed actuator


maybe these will help


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## fontgeek (Jul 24, 2006)

To kind of echo an earlier question or point, a lot depends upon how she would be sitting, and the angle guests would see her from.
If she was sitting cross legged facing a doorway (through which guests would see her), having her hinged at the waist with spring steel or actual springs at her waist so that she could be on a track, and simply getting pulled back under the bed would fold her in half as she's pulled under the bed. With a smooth surface above her, it would mean that there's nothing for her to catch on or get hung up on when she's pulled under or pushed back out for the next showing. Adding a simple strobe to help add the drama would be a nice touch too. You could use a simple piston to push and pull the girl from under the bed. Her torso can be built using spring steel hoops or arches that would give some depth that's flexible and super light weight. The spring steel is easy to find in new or old automotive sunshades (those springy hoops with nylon or polyester cloth covers that fold up to something the size of a frisbee).


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## Daphne (Oct 18, 2006)

Welcome to our merry little band of haunters! Very creative idea, I’ve never seen or heard of that being done but I like it! I’m having flashbacks of the Monsters Inc movie which I adored and being terrified of stuff under my bed as a kid! Why I thought hiding under the covers was going to protect me I will never know, but I digress. 

I knew folks would have great ideas to share, they always do!  I may be saying essentially the same as Atticus Finch but I was thinking that you could have a cable from the head attached to a pulley in a tree or frame above the scene. It would be slack to allow the doll to get yanked under the bed. To reset, a motor would tighten the slack to pull her back up into a seated position. My only concern is how do you release that cable to allow her to get yanked under again without her falling over from the slack? Could she be propped against a pillow backrest so the cable pulls her back up leaning against it? That would solve the falling over but how you you make the motor release the slack? I’m confident our gurus will continue to have slick suggestions. Can’t wait to see how you do this!


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