"Moooo" Rare Swiss Cow Project has begun
December 18, 2009
Following on from the Laser Experiments i have decided to attach it to some kind of walking Robot.
I am now a avid fan of Theo Jansen - after rik brought him to light in his Blog.
So far i have Prototyped two pairs of "Theo" legs using "MindStorms" as an experimental base.
It worked better than i could have imagined - these legs go like a Cow on its way to the milking parlour.........
Only problem now is what medium shall i use to make the final version.....
.....and how the blasers will i get it to turn - may have to run it off 4 motors and double up on the number of legs.
First stage is to replace the Lego Mindstoms with something more exciting..... Wood.
This worked well ..... however after looking closely it suddenly dawned on me
that there are two fixed triangles in the arrangement .....dduuhhhh,
( it puzzled me to rik why you coloured those bits in green )
so i simplified the mechanism with well yes 2 triangles........and 2 flexible squares.
I used the Hypothenus as the fixed link static anchor points (yellow motor and wood spar)
The motor is a geared motor courtesy of "OddBot"
Using some PolyMorph i was able to quickly construct a crank arm,
with PolyMorph it is so easy to tweak the orientation and length,
giving a super smooth gliding effect....
Second Crank arm made and the yellow motors changed to GM2s for lower speed and higher torque.
Also at long last it has four Legs - and the arduino with motor controller driving them.
Made 2 extra legs and for more torque installed two GM2 motors
Syncronising the Legs :-
I had a problem with the missmatch of the legs - ie she would not walk straight with equal power going to each motor.
So i installed 2 QRD1114s, one pointing at a flat region with painted line on each motor drive shaft.
So both motors send a sync pulse every revolution - if these occur at the same time then all is well and the leg motion keeps a straight line.
When there is a difference between the arrival of the two sync signals a control action is made - stop one motor (slave) and wait for other motor (master) to catch up- then restart slave motor - back into sync and cruising straight again.
I have a number of other strategies - all based off the QRD1114s which will unfold.........any other ideas greatly welcome.
Time for some cosmetic surgery - Swiss Cow gets Her "Beauty Treatment"
Using first a Cardboard Template
i crafted the PM with some "Skinning" techniques.