Let's Make Robots!



hi guys! i'm working on a project. it's a biped (two-leg robot). i think the animation(click on the image) shows the most but.. that on the top is a hard disk platter on a fast spinning motor. it must act like a simple gyroscope, keeping the robot straight.. i'm not quite sure, if it's gonna work, but i'll try :) i have all the parts and i have allready build the"body", but i don't have a torx screwdriver to unscrew the platter :( so till i find one i have to imagine only what will happen :) any ideas? please tell me, if you are sure, that it's not gonna work. why? 10x!

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Of course it will work ! Even if it's only for .25 seconds.. the gyroscope is more stable the faster it spins and the heavier the platter is, of course both of these things will make it more destructive when it falls over.  Another thing you might consider is the gyroscope is turning one direction - this will make the robot want to turn in the opposite direction - so if it does last longer than .25 seconds, your robot will want to do a tight turn...   The more pointy shoes will make it easier for the bot to turn - so you might get a few pirouttes before falling over..

good luck! 

you are deffinetly right about the spinning and i knew it. there are several ways to fix this problem, but i wanted to make some experiments first to consider what will be the best way for doing it. here are some examples

spin fix

1. two spikes on every feet
3. one of the legs make shorter step

i consider using some kind of pendulum too

2. that is some platform to keep the disk away from the earth, when the robot falls down 

Seems interesting. I can't decide if I think it'll work or not -- I could see it going either way. All I can say is I want to see video :)


if the length of time for success is 250 uS - I think it will make it :P

Hi, this is surely original :) The idea of keeping it balanced with something spinning is nice. For what i can understand, i think Grog is right, it will be unstable becouse when it's on only one foot, the body will probably turn around itself. I think the only way to stabilize it is to add a second plate spinning on the opposite direction.. This will probably make it more complex to build, but i'd love to see the results :)

If I remember the physics correctly from my r/c helicopter days, the spinning disk should only cause the robot to turn while it's accelerating or decelerating. Once the disk is spinning at a constant speed, I believe it shouldn't exert any rotational force on the robot.


i thought the second rotor on the tail fix the problem?
That's how it should be, unfortunately, it is always accellerating and doing work against friction (air and otherwise).  Although I guess friction in the bearings is still within the system, so in a vacuum, the robot will not spin itself out of control?

counter rotation would cancel the effect - also you might consider pads vs spikes - the increase of surface area of the foot wood help stabalize it too - depending on the material its foot might not come back up (also might be harsh on the coffee table)

the smaller diameter disk is not as effective - larger diameter = higher speed at the edge , higher speed = better stability - possibly you could widen the body until its outside the edge of the disk. 

BTW - what programs do you use to animate & draw?




    I see you’re trying to build a bipedal robot--hey me too! But I’m gonna use a mechanical walking frame and adapt that to walk on its own…different from your gyro-thingy but I’m coming round to maybe using something similar…I’ve to solve the balance problem as well.


Regards J