This Halloween I’d like to make a display of a person sitting in a chair, lifting and lowering its hand every so often. What I’m thinking of is having a motor attached to the ceiling above the display; a wire attached to both a lever on the motor and a hand on the person; and with each revolution, the lever lifts the wire (thus, lifting the hand) and then lowering it (thus, lowering the hand).
Kinda as shown in this drawing. (You’ll have to pardon the questionable artwork.)
My question is, where would I find a motor slow enough to do what I want? I don’t want the motor to run so quickly that the guy looks as if he’s having a seizure, but I do want it fast enough so passers-by can see he’s waving. If I can get this to work, I’ll eventually try something similar with a motor and a coffin lid.
You want a gearhead motor. They are available in a wide variety of gear ratios and operating voltages. You just need to determine what RPM will give you the results you want.
You want a gearhead motor. Jameco has them in a huge range of voltages & rpms.
Micro-mark sells one under the name “animation gearmotor”.
Or you could probably hack it for less money by modifying a cheap kid’s toy. Back when I did more of this sort of thing, I’d prowl around Toys-R-Us looking for things that did almost what I wanted to, then I’d rip them apart and get the bits I needed.
One year I built a shark head that had a jaw that opened and shut, and that was mostly done with bits from one of those little yapping dog toys.
Thanks for the gearhead motor suggestions, Q.E.D. and buckgully. I’d actually seen those before, but the ones I had come across revolved at a significantly faster speed than what I wanted. Plus, I’d have to attach it to a power source, and I wasn’t sure about how to do that.
Your kids toy suggestion is what I was thinking of (that, or a clock), buckgully. I remembered cannibalizing my Robotix motors for many a school project way back in the day, and thought maybe I could find something similar these days. But, it looks like I won’t even need to take a trip down to the local toy shop; I found the Micro-Mark site, and it looks like the animation gearmotor is exactly what I need.
Fifty-eight RPM was still kind of high for what I was looking for; the 2.5 RPM gearmotor is more what I need. I just want the arm to lift up and down slowly; at 58 RPM, it’d be moving too quickly for the effect I want. I was probably too vague when I was explaining that.
As for the power source, what I mean is that, with the animation gearmotor, I won’t have to attach a power cord or battery to it; it already has a power cord attached, leaving me with less work to do.
