pic: Robo-one legs

[[527]phil]

yeah I'd like to see a wheeled robot do a back flip, lol. But if you could provide any code examples it would be nice. I'm not much of a programmer.

[mechanicalbrain]

sanddrag makes a valid point but i think you are going to see more motor problems at the bottom. if you can run different amounts of current to different motors run about 8 volts to the bottom motors.

[[527]phil]

I figured out one major problem with the legs, i need to take out one servo from each leg, not only will this make it more stable, it'll make it easier to program.

[sanddrag]

Originally Posted by mechanicalbrain

run about 8 volts to the bottom motors.

I think 8v is far too high for most hobby servos. I think about 6v is the max.

[Mike AA]

Originally Posted by [527]phil

I figured out one major problem with the legs, i need to take out one servo from each leg, not only will this make it more stable, it'll make it easier to program.

I was beginning to wonder why you had some many servos. You should only need 3 per leg (just like human legs) including ankles. It would definatly make things easier.

-Mike

[mechanicalbrain]

i like the idea too often i see robots bound by the constraints of biology. make biology the base and then improve!

[Gdeaver]

If I remember your past post about the atom, there was a problem with your use of the servo command. Look at the docs on the servo command.
Servo 1,5 will repeat this command 30 times by default which takes about 1 second to execute. Try servo 1,5,1 This will take about 30 ms to execute.
To control that many servos you going to need a servo board. Most servo boards are serial or I2C controlled. Serial is probable easier, I2c is most likely faster.

[mechanicalbrain]

Originally Posted by sanddrag

I think 8v is far too high for most hobby servos. I think about 6v is the max.

you can run the Hitec and Futaba servos on 12 volts DC even though its rated for 6 volt. also you can run almost any servo on roughly 8 volts.

[[527]phil]

this is robo-one legs 2.0. I took off the knee servos and not only is it shorter, it's much more stable.

[mechanicalbrain]

hehe he's stubby!

[John Gutmann]

Originally Posted by Mike AA

I was beginning to wonder why you had some many servos. You should only need 3 per leg (just like human legs) including ankles. It would definatly make things easier.

-Mike

you should need 4 servos per leg cuz the leg has to rotate 3 ways(forward/back, left/right, and to rotate the whole leg) that way you can turn

[mechanicalbrain]

ive been compiling info to write a whitepaper on bipedal walking so tell me how this turns out. one of the things i want to see and i think would be extremely usefull to a better system would be the addition of bending toes and able to lean side to side. both of these are extremely important to human balance. if you don't believe me try walking without bending your toes or shifting weight from side to side.

[[527]phil]

It's having a weee bit of trouble walking, but it's not because of my designs it's because of my programming, I still haven't mastered the HSERVO command, + I've been searching for a Pentium 3 laptop, kinda like an IBM think pad or a dell latitude, but alas i keep getting overbid .

what happened to the pic of legs 2.0?

[mechanicalbrain]

but can it actually move?

[[527]phil]

Yes he can move. all servos work perfectly and I calibrated the servo horns so they are at the 0 position (or almost). I can move single servos or multiple ones. It's just in order for it to walk on it's own i have to find the exact placement of each servo so it won't fall over. But it's alive!!!, lol