• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

drum robot...argggg

Status
Not open for further replies.

ale2121

New Member
hi all.

I'm building a simple mechanism to play a drum. I've got a 555 timing circuit to control the speed of a motor. first i built it like this (beware it's noisy):

YouTube - Drum Video

but, i don't like how erratic the mechanism is.

so i rebuilt it with a roughly 4 inch cam i made out of cardboard mounted directly to the motor. the drumming is less erratic now, except that the motors are burning out (i think). My guess is they're cheap motors, AND it's an off center load. Also, in both cases, I have to turn the PWM way up to get the motor going, then turn it down to where i want it. So, do i just need higher torque? or a different mechanism entirely? I like the cam because it allows gravity to come into play, but I'd also be willing to try some linkages to make linear movement instead. Unfortunately, I don't know how to make linkages without a prototyping machine. Also, I'd super love some worm gears that would fit my situation, again, don't know where to get them, or how to decide which ones I need. Anyone have any advice? I'd really love it.
 

Hero999

Banned
What about doing this electronically?

It's pretty easy to make a drum sound using an oscillator with the gain set too low for it to oscillate.
 

ale2121

New Member
i agree, it's not that difficult, as long as i can get my hands on the parts. anyone know a good place to get either worm gears or linkages that will fit hobby motors?
 

Hero999

Banned
A solenoid?
 

Sceadwian

Banned
The thing about drums is the weight of the stick is what does most of the work especially on faster drum rolls. Usually a human hand is simply acting as an elastic device and it's being fed momentary pulses from the muscles to give a little bit of energy on the up stroke. So I'd recommend using a jig of some kind holding the drum stick but giving it some flexibility and then somehow connect a motor to that to provide impulses. The travel does not need to be very far.

Looking at your drum video again I think you might get significantly better results by simply attaching a rubber band to the drum stick in such a way that it provides a bit of tension (very light but play around with it) to hold the drum stick to the drum itself. Then you cam arm will have better luck driving it.
 

ale2121

New Member
I have a bunch of solenoids, but they hold a charge for too long and won't release when the electricity turns off. I don't really know how to rate them, maybe these just aren't the solenoids I need? but as they stand they won't work for what I need.
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top