usless box

zaphoid

I want to build something like this.· But different.

http://www.youtube.com/watch?v=7bE7U0fHtQ8&feature=player_embedded

I dont really want to use a stamp and a couple of servos, I want it to be cheap. ·I think I can get the motion I want with a relay, two switches and two DC motors.

But I need some gearboxes to put on the motors.

So my question for you guys is, where can I get some small 3 Volt DC motors with a large gear reduction.

Like this:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXHA26&P=ML

but cheap.


I figure you guys are my best bet for knowledge about cheap and small DC motors.

Post Edited (zaphoid) : 9/29/2009 1:04:12 AM GMT

Phil Pilgrim (PhiPi)

Here's a site that may help: www.solarbotics.net/library/pieces/parts_mech_grmotors_compar.html.

-Phil

erco

You can make it work without any electronics, but you won't get the short time delays necessary to get the same action. The arm that flips the toggle switch back retracts quickly, then there's a delay before the box lid closes. You can get by if you just make the arm retract more slowly to fake a delay, and then the lid will begin closing instantly once the arm fully retracts.

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·"If you build it, they will come."

zaphoid

Phil Pilgrim (PhiPi)'s link lead me to: http://www.allelectronics.com/index.php Which has a few small cheap DC motors with gear heads. Thanks, now I must think.


My general plan is to use a cigar box, not a see through box. There would be no second arm to lift the lid. Because of the cigar box shape, the switch would have to be on the front or side, not the top. I think the side is best. Picture an arm with the elbow at ninety degrees. A four bar link raises the arm above the top of the box and over top the switch. A hidden switch stops motor one and starts the shoulder motor, which rotates the arm down, hitting the switch. Another switch reverses power when the shoulder reaches the right travel limit.

My arm would be more like a doll baby arm. I also plan on holding the box shut, so no one can see whats inside (maybe have the bottom open for batteries once it all works perfectly).

Just a box, with a switch. Hit the switch and an arm pops out flips the switch back. No explanations nothing.

erco

You can do it with one motor, and it doesn't even have to reverse. Just have the arm go through one oscillation as it is attached to a large gear or crank. The arm just pushes the lid open as it raises up, and it pushes the toggle switch at its extreme limit. There is a Normally closed "home" switch on the main gear/crank that switches off the motor only in the home position. The external toggle switch is in parallel with that home switch so it restarts the cycle. As soon as the main gear starts rotating, the home switch closes to keep the motor going after the toggle switch gets switched off, until the home switch gets activated again. You won't even need dynamic braking on your motor, because you can have a lot of overlap on your switches and it won't hurt if your motor coasts a while after the homing switch opens.

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·"If you build it, they will come."

Alsowolfman

You should try thrift stores in the toy section. You may be able to get the right motors from animatronic toys, like the big mouth billy bass, i think it has separate motors for moving the tail and head.


here is a video of one.

Carl Hayes

Is an usless box one that doesn't have us in it?

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· -- Carl, nn5i@arrl.net