Thread: Please Watch My Motor - Need You!

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Ok I'm going to be honest, this is my real first prop I've tried building on my own. I've had alot of fun with it so far and my fog chiller which I guess is another custom build... I'm getting into this like you guys, just like you said

With that said, I'm posting this video of my problem and my haunted chair. Either I'm an idiot and don't have the right idea, or I'm missing something....

If I try holding the motor for test purposes and run it, the motor tries to life up on its own in my hand. Then I tried half-ass mounting it to see what happens, and the plywood lifts up?

I mean, do I have to have the whole chair on a piece of plywood or something? Is that what I'm missing, cuz I really didnt wanna have to do that.

Thanks in advance as always!

[ame=http://www.youtube.com/watch?v=DvdcRHhdRyk]YouTube - motor help[/ame]

looks like you got the right idea. You just dont have enough Mass( weight) on the board the motor is mounted to. The chair has more mass, so instead of moving the chair you are lifting the motor. Also you may need to move the motor/mounting board back from the chair, because right now you are pulling straight down and not back...rock back and forth. i would frisrt stand on the board and see what happens when it is running. that should work. then slowly move the board back away from the chair and I think the rock motion will get better.

good luck

need some weight on the bored or mount it to the floor so it wont lift up

Aye, tha' be th' probelm.. ya needs more weight on th' board.. bigger board(so th' chair legs arrre on it, change th' pivot point off th' back o' th seat to th' leg o' th' chair, or jus' put a cinder block on th' back o' th' board..

I think the arm that connects the motor to the chair is to short. You have good rocking motion but when the chair is rocked back nearly all the way the motor crank should be at it's lowest position and it is not (22 second on the video), hence pulling up the wood.

-PB

Wow, thanks guys, appreciate all the feedback.

My main goal was to build a small box around the motor to conceal it. Although with everyone telling me I need more weight I'm not sure if I can even build a box around the motor now. Right now its on 1/4 plywood. Maybe I should up it to 1/2 inch ply right? Then use some better brackets to mount it.

I still think the motor would lift the board, but like others said, I should put something heavy then in my box right? Thats the feelin I'm getting....

Ya must make th' board wide 'nough fer th' legs of th' chair ta sit on it.. ya canna 'ave th' board completely free of th' chair.. make th' board wider, an' 1/2" thick at least..

go check this out
http://scarefx.com/images/rockin_gra...kin_granny.jpg
very well done rocking chair

Actually, you can have the chair independent of the board, if the board weighs enough. You may get some rotation of the chair, though, if the mount isn't pretty much dead on center. When I made my chair, I opted for the large board - easier to control. I also used a snug bungee cord from the center of the chair bottom to the board to stabilize the chair.

[ame]http://s73.photobucket.com/albums/i231/Otaku1031/?action=view&current=MOV06407.flv[/ame]

It's the arm. The arm is too short so when it does a full rock, it has to lift up the motor in order to complete the motor's revolution.