Let's Make Robots!

playing dr frankenstein

While out on the town during an anual festival I ran into something that I though would make a fun robot project.

Namely this thing:


 it's a cheap toy robot that drives around making miscelanious annoying noises. It's 20 cm tall, 12 cm wide and 12 cm "deep". It drives around using a small DC motor powered by 3 AA's. The first thing I did when I got it home was take it apart, and as suspected it's fairly empty.



 My Idea is to "upgrade" this thing with my picaxe chip, some servos and an ultrasonic sensor for object avoidance. I'll keep the battery compartment as is but replace the little DC motor with two modded servos. I thought I'd make holes on each side where the axles for the blue wheels are:


and attach the wheels to the modded servos after adding something to increase traction on the plastic wheels. Then I'd add a servo to control head movement and replace the eyes with an ultrasonic sensor:IMG_3284.jpg


if this all works I might add more stuff. If there's room it would be pretty easy to add servos to the arms and possibly a speaker or something. 

what do you think?

I don't know much about servos, but I was thinking about using these


I would really like to hear your opinions about this before ordering servos and stuff. what do you think? can it be done?


Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.


I had a look at the GM3's dimentions and I think it'll fit. I think I'll get two GM3's and three of those servos.


And you dont have to add any speaker, it's already there. 

Fritsl: I think He wanted to know if they'd be strong enough to use as motors for the big blue wheels.

/ vzz-clck-"Maneuver"

Oh - but it already was driving around, no? nad motors already? ust hook em up :)

I have no experience with using servos as "motors, thanks.

yes, there's a motor, but it's not driving any of the big blue wheels

it's hooked up to a series of gears that drive two small black wheels on the bottom of the robot. it allso drives a black plate that the wheels are attached to which spins. so the robot drives around and bumps into things. not very useful. I'll film the robot in action and link to it here when I get home from work so you'll see what I mean.

I think that the modded servos will be strong enough, as long as I don't add too much weight that is.


anyone have any experience with these servos modded for continuous rotation?



I used servos as my drive motors in Harry The Discbot. They worked out alright -- it was a little slow and underpowered, but now that I know more about electronics, I think my incorrectly made homebuilt H-bridge was to blame for that. I think they should be fine, especially if you spend a little more and get servos with a little more torque than the bottom-of-the-barrel ones. But personally I'd tend to favor something like the Solarbotics GM2/GM3 instead -- they're cheaper, and they're designed for this task to begin with.


ok, I will

do you think the servos I've been looking at are strong/fast enough?

I think they're small enough


If all they have to do is lift that small plastic arms, they are plenty strong!
Of course it can! It will be cool! Use 4 AA's, because the motor driver will reduce by 1.5V!