Hank V1.0

 
#1

Hello everyone!

My EZ-B came in little over a week ago. The delivery time was great, no problems
allthough I had to pay a considerable additional amount for import. Other then that
it came in just fine and on time. So I started building my hexapod robot,
I call it 'Hank'. Grin

He is made out of an old Cisco E1000 wireless router I had laying around.
Its got 6 legs, each using 3 high torque servo's (18 servo's total). Its got
one ultrasonic ping sensor mounted staticly without any servo's. So all 20
digital ports are taken. 2 for the sensor, 18 for the legs. I will have to say
that the board does indeed brown out fairly quickly, even with the use of
the table powersupply I ordered with the EZ-B. So alternate power for the
servo's is a must. If anyone could show me a picture of where to cut the
proper leads on the board for an external battery source, I would really
appreciate it very much, as I do not want to damage anything. Tongue

Allthough I have begun compiling some scripts for centering the legs and forward
movement, it can't rightly stand nor walk by itself yet without browning out almost
instantaniously. I also notice that while compiling the scripts, the command for
'servospeed' does not seem to affect the speed at all. Maybe this is due to the use
of high torque servo's, I'm not sure, but the servo's seemingly keep running full power and
obviously Hank is one hyper robot, lol. But it uses a lot of power too, anyone
have any ideas of how or why I cant seem to slow it down? Ive tried
combining it with the 'sleep' command for several seconds but it will infact just wait
that time untill whipping out the next movement with full speed. I need to slow that
down somehow.

Obviously, this is just a quick mock-up and it needs a lot of improvement. Allthough the
frame is basically as it is, the legs ive slapped together outof some aluminium tubes
and are hot glued onto the servo mountings. The included plastic servo mountings are
quite soft and with the tubes glued like this, the legs bend and wobble easily and do not
offer enough support to stand on. the outer legs ive just hotglued on a tie-wrap that is
wrapped around their servo. I have ordered black acrylicglass but am still waiting for it to arrive.
When it does, i will begin finalising the legs properly and possibly include the lower base
of the frame. The router casing needs some final touches too. On the back it has a connect
button and the led indication symbols. I intend to place 2 leds and switches for the batteries
under the 1st and 2nd network symbols, and possibly attach some optic fiber cable to light up
the power symbol on the left using either led on the board. I was also thinking of possibly
placing 2 solar panels on its back to provide both batteries with a little extra charge.
I am still looking for a suitable battery for the servo's, as this will need enough amps
to feed all the servo's, without being too large and will not exceed 6v. though some
datasheets for the servo's show 4.8v - 7.2v range, would a 7.2v battery not be too
much for the servo's?

Well anyway, Ive attached some pics. I hope you guys like it. Though keep in mind
that the legs are temporary so I could begin making some simple scripts untill I receive the acrylic glass lol. Grin

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Thanks, DJ Sures! I'm really enjoying EZ-B, with EZ-Builder I can easily set up some basic
scripts without any scripting knoledge and control it with my wireless 360 controller. Grin
It's awesome! (oh, and I got a red LED on my board! Grin)

Kristian.

#2

OMG i see my router walking away.
Thats so cool!

My router died last weekend but when i saw this Smile
Nice idea

Dat heb je echt mooi gedaan zeg!

#3

Ha! That's awesome

#4

It kind of creeps me out. I Love It!!!!!

#5

awesome bot love to see a video of it running

#6

Yes please show a video! I'm super interested

#7

Outstanding..that really looks great! Can't wait to see more of it and some of the movement scripts you come up with! I would guess the multiservo function DJ just added will be very handy!

#8

Wow! That is awesome! I'd really like to see a video of it walking!

#9

Can you upload a video!!!?ยก???? and that is awesome!! I want to see how to work your robot!!

#10

Hi everybody. Thanks for the positive reactions!

I would love to upload a video that showes Hank working properly. However, as I have already said
in my opening post, it can't rightly stand nor walk by itself just yet. This is because I am using
a total of 18 high torque servo's, out of which at least half are running at the same time
at one time or another, they start to draw more power then the board with its 5v regulator
can provide. At which point the board suffers a 'brown out', all functions basically fall dead
and I will need to pull the power plug and reconnect. right now I have it resting on a stand,
allowing it to operate without the constant load of actually having to carry itself. and even
then it can only work at a constant rate for a short while before also browning out the board.

So unfortunatly I do not yet have, and am still looking for a proper power source to feed all (or most) high
torque servo's seperatly from the board. When I do have that power source and when I
feel I can proudly show you all a properly working Hank, I will most definitly upload a video. Tongue

@ kkeast

Thanks! I have to say I have NO scripting experience lol. All I know is from what ive seen
from the examples within EZ-Builder, and the right side hints on the EZ script window.
Basically its just sequences of a set positions for each leg, with here and there pause
to organize it a little. Unfortunatly the command 'servospeed' does not work, so i cant slow
down the movements themselves unless i manually divide any movement for all servo's into
small increments and short pauzes. Which needless to say can become fairly complex. lol

For forward movement I have basically used 3 set positions for all legs, which is to extend the leg,
then push or pull itself forward, then raise the leg, and then it repeats untill a 'stop' script ends
all movement scripts. To maintain balance it's going to have to at least have 3 legs on the ground.
So lets say the front left, middle right, and back left leg is group A, and the front right, middle left and
back right legs are group B. Group A will move all its legs to a forward extended position, while group
B already was in forward extended position in previous step, and is now push/pulling the robot
in a forward motion. In the next step, group B will raise its legs before extending them again, while
group A is now push/pulling the robot in a forward motion..and so on, and so on.

Example:

# step 1.1 Group A legs up
# front left leg
servo(d1, 65)
servo(d2, 50)
servo(d3, 60)

# middle right leg
servo(d7, 5)
servo(d8, 10)
servo(d9, 35)

# back left leg
servo(d13, 65)
servo(d14, 20)
servo(d15, 60)

# step 1.2 Group B push/pull forward
# front right leg
servo(d4, 55)
servo(d5, 25)
servo(d6, 23)

# middle left leg
servo(d10, 50)
servo(d11, 45)
Servo(d12, 35)

# back right leg
servo(d16, 50)
servo(d17, 20)
servo(d18, 45)

sleep(500)

and then there is step 2.1 for group A and step 2.2 for group B, then finally step 3.1 and 3.2 to complete
the cycle. it simply repeats itself or is interupted by the 'stop' script that ends all movement scripts. The script
is real basic and the first thing ive come up with. Then I suppose its a matter of refining all the various moves
and their scripts. All the scripts for forward, reverse, right, left movement and stop are simply named so and refered to by the movement script in EZ-Builder with 'controlcommand("forward", scriptstart)' etc.

My 'stop' script looks like this:
# stop movement scripts
controlcommand("forward", scriptstop)
controlcommand("reverse", scriptstop)
controlcoomand("right", scriptstop)
controlcommand("left", scriptstop)

I hope this sort of gives you an idea of what i've come up with so far. Tongue

Kristian.