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Hello all,

I have a question about wiper motors used for a FCG. I'm planning on building one later on for this season, but a was unsure about how much torque a wiper motor has. See, I'm designing it a little differently. Rather than the typical cheesecloth ghost, I'm planning on using an actual dress instead, but with no styrofoam head, making it look like it's just a floating garment with a body shape, but no body.

Would the wiper motor be able to withstand the weight of a dress or should I just stick with a typical FCG design?

Also, I plan on using the device that slows down the speed without loosing torque with it (the name of it escapes me at the moment). Could this pose a problem.

I've also seen discussions of building a FCG with counterweights, but cannot seem to find any designs for this. Would this be beneficial? How would I go about incorporating this into a FCG?

Any help you guys can offer would be greatly appreciated. Thanks!
 

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A wiper motor should have plenty of torque to lift a dress.
I don't have exact torque-to-weight values for you, but have used wiper motors for various applications and feel pretty confident that they can lift a dress.

The device you are talking about is called a "speed controller" or "motor controller".
FrightProps sells them here:
http://www.frightprops.com/electric-motors-1/controllers/speed-controller-for-dc-motors-linear-actuators.html

You might be able to get a cheaper controller on Ebay, but with FrightProps, you know for sure you are getting a controller that will work with your intended application..

A Flying Crank Ghost lifts the head, left hand, and right hand of the ghost separately. The best way to "counterweight" it and get the most efficient operation out of the motor would be to make all three loads as equal as possible. That way, the weight of the hands would help counter the weight of the dress and vice-versa.
 

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Discussion Starter #3
The device you are talking about is called a "speed controller" or "motor controller".
Oh yea! That makes sense!

A Flying Crank Ghost lifts the head, left hand, and right hand of the ghost separately, the best way to "counterweight" it and get the most efficient operation out of the motor would be to make all three loads as equal as possible. That way, the weight of the hands would help counter the weight of the dress and vice-versa.

I've seen talks about this being done with counter weights, but this makes sense too.

Thanks!
 

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Weight is an issue but the wiper motor has enough torque, you will need a PWM (pulse width modulated) speed controller to maintain the torque at slower speeds. Using a dimmer will slow the motor and reduce torque.

I basically used a wiper motor for my FCG with a flaming skull see my links in my signature below.
 

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one of the normal issues that FCG first time builders have is that the ghost is too heavy and "drops". this shouldn't be as much of a problem if you only have a dress. You may find that you actually need to weight the arms (with say nuts and bolts) to keep the line tight.

if you do have a heavy ghost (or heavy dress), the best way to counterweight it is to have another line attached to the crank totally opposite to the ghost line and have the counterweight the same weight as the ghost. this prevents it dropping as there is always a constant load on the lines.

great idea btw and one i may be borrowing......
 

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I have been toying with a wiper motor to move an 8' tall marionette. The body was simply too heavy, even with a counter weight.. This continues to be a work in progress as I just can't seem to get the body movement right. The motor wants to bind when lifting the legs at the knee - and I think this is due to the weight of the body is somehow transferring to the leg when I lift one. The counterweight idea sounds good, but I can't seem to wrap my head around how to do it. I will keep listening to this thread to see if something breaks loose
HM
 

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I have made fcg's with a single counter weight opposite the head, and with extra weight added to the hands. The weight in the hands worked far better for me. The extra weight in the hands keeps the lines in the pullys even when it gets windy. The single weight opposite the head requires an extra pulley, and is easily tangled in even a slight breeze. Also, if you add enough weight in the hands to balance the head, you should be able to drive the ghost you describe with a smaller motor than a wiper motor.
 
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