My first robot : a quadruped with 3 DOF by leg

It just trying to walk correctly for the moment :)

Update 2 : new video of the "spider style" walk

Hi everybody my name is MoX First i want to say sorry for my english : I'm French ...(and sorry for my president

So this is my first robot, a quadruped with 12 standard servomotors and 3 dof by leg.

I make all the part myself with aluminum plate.

For now, it's just control by my computer link to it with a RS232 connection, and a SSC32 controlling servomotor card by Lynxmotion (a real good card i think :)

Today I'm trying to control it with an Arduino car but the com with UART between the two cards is not operational for the moment :( I'm also trying to include a URM37 ultrasound sensor :)

The first step was to create a second axis for all servos.

I used some support of roller-blade ball-bearing, and I stuck it to the servo with cyanoacrylate adhesive :

Now , let's use my best enemies (which offer me a lot of blister ! ) :  Saw, file, and tech vice (lol not the same signification in French MDR)

The body :  PVC plate (dimensions 180x180mm,5mm of thickness) :

Now the legs : I am going to use the terms of "shoulder", "leg" and "scratch" for the 3 parts of the legs... (sorry I know that my english vocabulary have to increase .....)

All the aluminum parts are from an old 19" computers rack ( 2mm of thickness )

First type of servos support : for the 2 servos of the "shoulder"

I have fold the plate following the dotted line, using a tech vice :

It's very important to align correctly the axis of the servo with it's new axis (the bearing part)  and to follow this alignment with the aluminum support of servomotor. Personally it's not perfect (i wish i had a numeric CNC :) future project ?!

when you love, you don't count (French proverb) 3 more to make ... or you could count your blisters LOL : 600W blister by hand !! thank you Miss metal file ! ........ heuuuu if you don't understand the blister thing....just French technical joke LOL

And the result with servos , but not yet fix to them ( one of them is on the "leg")

The result with the 4 supports of "shoulders":


Now the support for the "leg" : more simple than the other LOL ...... but... but's just a poor piece of aluminum ?? ... YES o_O

The leg:

The result with 4 legs :

Now my favorite part : the scratch:

Same idea : Saw, file, and tech vice ...and blisters !

Result :



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Thanks for posting all this stuff ! When I see your robot, I can't wait to work on a walker ;) (but many things to finish first...).

To answer your question about the new walk, I must admit that I prefer the first one. It makes the robot less mechanical, more alive, agressive or suspecious, I don't know how to define it exatly... maybe the new walk just looks more predictible (because it is simpler... grrr god damned accumulators ! ;)

Keep up the good work :)

Rhaaa it's exactly what I'm thinking !!

When I program the second way to walk, my poor robot cry a lot and beseech me to not make him so mechanical (He was very bored to walk that way ..... like a poor military boy LOL)

My goal is to make it more alive , more suspecious, more ...the way you think ! (good point of view ;)

So I'm alway working on a walk that could respect my goal !

Have fun with your robot ...and the rest !


Hi everybody :)

This is an evolution of the "spider-style" walk of my quadruped.

I'm pretty proud of this one : servos consumes more but with the weight of the NiMH accumulator,it's acceptable and I think i could have 1 hour of autonomy ...(theoretically). It's also more stable that the first "spider-style" walk (the first video).

There is always a little trouble with the last step (but I'm on it).... :)


PS : A special sign for LordGG : more alive, aggressive or suspicious ..... give me your opinion dude ;)

Have fun everybody


Great compromise :) It keeps a wild behaviour, and if you've succeeded in reducing the energy consumption to an accetpable level it is perfect !

Je reste dans les parages pour voir la suite ;)

Thanks dude ! :)

Huve fun


HI, FRIEND i am an engineering student and is intrested in making that bot for my final year project can u pls help me with dimensions of every part. it would be helpfull.


that is just beautiful... and a healthy reminder of why i decided to learn robotics (and am awake at 3:00am on a monday morning)

Nice job all this hand work! Mes félicitations! T'a bien travaillé lá! Il se bouge pas trop vite mais ca ira! Bonne chance pour la suite!

Keep it on!

Hi Mox,

Very nice work, especially as you build everything from scratch.

If you want to lose the robot tether, look at Xbees. They are simple to setup and you can get a 56kbit connection.

hi mox

i have made a project just like yours.

the only thing left is the wiring of the servo motors.

i was wondering if you could help me with that and also the code if you could send me that over my email.

( )

that would be really kind of yours

thank you......