# help making doll's heads turn



## Ryan Wern (Dec 3, 2009)

We recently moved from CA to Nebraska. I didn't plan on doing anything for Halloween this year but of course I just HAD to do SOMETHING. I am very limited on supplies because I had to leave most of my wood and other parts behind due to limited space in the U-Haul. Anyway, I know it's short notice, but I need help. I have 4 plastic dolls that I painted and placed on a shelf. I want the heads to turn about 1/4 turn and then reset to looking forward (or neutral). I have the dolls sitting on the shelf and have wooden dowells running down through the body and the shelf so that there is about 3'' of dowell is sticking out the bottom of the shelf. The dolls heads are screwed to the top of the dowell, allowing the heads to turn smoothly. Follow me? So I had the idea to attach eyelets to the bottom of the dowells and another dowell with eyelets that runs parallell to the ground hooked on to the dowells that run through the dolls. The idea was to create a push-pull linkage. This thing is powered by a Christmas deer motor. I hope I illustrated this enough. The problem is that the linkage I made binds up on the middle 2 dolls. I have tried about 3 different configurations of linkages and nothing works. I have to get a push/pull motion with a deer motor but (probably because I'm rushing and don't have JACK to work with) I can't figure out a good system to make these things work. Again, all I am trying to do is make the heads turn 1/4 turn (toward the ToT's) and then turn back to neutral. I have a motion sensor that sets them off. PLEASE HELP if you have done this or have any ideas! Thanks and happy Halloween


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## Indyandy (Sep 7, 2005)

I don't know if this will help or not, I did something similar to this motion and the motor wouldn't push the prop back. So I did away with the push/pull rod and put a crank arm on the motor. Then put an eyeloop perpendicular to the verticle rod. Take a string and tie it to the eyeloop and the crank arm. Put a spring on the eyeloop and fasten it to pull the rod back into position. You could tie each verticle rod together in series with a spring on the last one. You will have to play with spring tension. Hope this helps.


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## Otaku (Dec 3, 2004)

I think I may know whats up here. Is there a chance that the two middle links are a slightly different length than the two on the ends? That would cause the center portion of the long dowel to be either pulled toward the dolls or pushed away during each cycle.


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## hedg12 (Jul 6, 2008)

So if I'm understanding this correctly, you have 4 vertical dowels with eyelets coming off the bottom perpendicular to the axis of the dowels, and 1 dowel perpendicular to the 4 with 4 eyelets interlinking with the eyelets on the vertical rods. Are the eyelets perpendicular to each other? They might be binding or causing the vertical dowels to rotate at different angles if they're not.


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## Otaku (Dec 3, 2004)

I like Indyandy's suggestion, too. Having a return spring on a common string tying all of the vertical rods together would solve the need for having to have precise spacing between the eyelets. The spring would be under tension at all times during the motor rotation, so none of the heads would be out of sync with any other during the cycle.


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## Ryan Wern (Dec 3, 2009)

@hedg12 and Otaku- That was exactly the problem. I made this thing on short notice so my attention to detail wasn't the greatest. I used Indyandy's suggestion and it worked great. Thanks for saving me!


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## RoxyBlue (Oct 6, 2008)

Ryan, do post a picture of how you did this when you get a moment. I think other folks would find it helpful.


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## hpropman (Jul 27, 2008)

yes a picture please I am having trouble visualizing it.


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## Ryan Wern (Dec 3, 2009)

you bet. now keep in mind it's kind of cobbled together, not a work of art, so it works but there is miles and miles for improvement. would have rather had quarter-turn servos in each doll, but no such luck, just a deer motor and scraps of wood and metal. If you think it's cool, feel free to use it. Cost me nothing. If you think it blows, do it your way so I can copy YOU next year lol.


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