YDNA Robot, first prototype done

[noDNA]

Hi all,
just wanted to show my first prototype of YDNA (Why DNA?).
This robot will be released in a small series. Having finished this prototype I now know many things I want to change in version 2 of this pre-release.
Some specs right now:
has 3 different servos, small one for head, most others are Dymond 9500 Servos (12kg/cm2). currently 2 in each leg are Hitec 5955TG (24kg/cm2), I have to add one of them in each upper leg. Total is 5 each leg and 4 each arm plus head = 19. The Hitec servos will make this guy very expensive (120 EUR /each). I will try to keep it below 2000 EUR.

Controller is currently a 32channel SSC-32 controller by Lynxmotion. An Atom board can be added on top of it. I will evaluate another smaller controller too and then decide which one to include finally.

Power supply is 6V and a 9V battery for the controller. 6V can be supplied by two batteries, one in each leg or or obth on back, have not decided by now. Operating time is about 20-40 minutes with one battery (1200mAH) depending the actions involved.

I worked some months for the design of the parts. All parts are made by myself with as small home built CNC machine. I did anodize the parts at a 3rd party company to make the robot look nicer...or meaner....
No videos, have not done any motions up to now. No time, but I show it on the RoboCup next week in Bremen, Germany.

Here some images:




hope you like it!
noDNA

[tron81]

Very nice noDNA!

Robot kits are very difficult to find here in Australia (i've not found a distributor yet) and i've been working on my own prototype based on the KHR-1.

That is really really nice though. Did you build your CNC from plans? or?

[noDNA]

Yes and no. I purchased a used one through ebay. 500 EUR. Had no controller board.

Added a controller board, blew it up several times, bad design. Added a new controller board, good now.

Started to drill 1,5mm Aluminium, blew up the stepper motors. Changed them to stronger ones.

Drilled with the stronger steppers, blew up the drill. Changed this to a bigger one (was Proxxon 250W, is now Kress 900W drill)

So I learned: whatever you plan use stronger Motors, stronger drill and not the cheapest board as controller. Final investment was about 1000 EUR.

Every part takes about 10-20 minutes to drill. But handling adds to about 40 minutes per part. All parts for one robot take about two weeks.

I will speed this up of course. Good is for now that I can construct a new part within one hour until I have it in my hands. Came very handy for the head design of the robot
noDNA

[tron81]

Awesome - nice work. Your robot is totally sweet. Those brackets look like a good design too - i'd imagine you could make lots of changes to the layout of the servos pretty easily, yeah?

Congratuations again!

[noDNA]

Yes, the brackets are designed to fit in a variety of ways and to save weight at the same time.
I have included ball bearings for all joints. I use screws to fix the ball bearings at this time, but I might bolt them later. If you apply a heavy, heavy force the joint backet might slip off the ball bearing. I am thinking about a big washer to prevent this. Thats why I did not bolt yet.

The material is 1mm aluminium. I did tests with 0.8 and 1.5. Solution is now that 1mm is best for this purpose.

Overall weight 1,75 kg only

Height: 48cm

noDNA

[noDNA]

Hi all,
I added some other Hitec 5995 servos to the legs.
I replaced the leg rotation from the hip to the upper leg.
Now he has 12 servos with 20kg/cm in the legs.
Arms are still weak, you see there is no holding torque.

One 5995 servo died, do not know exactly why. Did not get hot but I guess jumping puts too much sudden force on the metal gears and they transport the energy to the motor.

Finding out about it is getting expensive, already blew up three servos: HG5995, KRS2350, DS9500

I used the SSC Sequenzer from Lynxmotion to program a simple jump. It actually lifts off the ground.

I looped it and you see this in a small movie here: (900kB, wmv)
http://www.nodna.com/media/products/YDNA/videos/YDNA-hopping.wmv

Hope to be able to show more exciting moves if I ever have time.
Currently I assemble my first Biped Scout Stalker from Lynxmotion, something different...
regards
noDNA

[limor]

YDNA looks much more stable than last time i saw him..

how about walking?

[noDNA]

Tried to do walking step by step but did not look good.
The reason is that walking is basically falling forward and stopping the fall by the foot. So it is not a good idea to do a keyframe step by step with well balanced keys. takes too long and is unnecessary complicated.

I will try the "falling method" soon and will post the result here again.

In the video above the YDNA is actually more unstable as usual, I guess it was low battery or simply too late at night....

When I did the first jump with YDNA I was impressed. It lifts about 3-5mm off the ground by just stetching the knees and ankles a bit, fast of course, but not too fast, the trick is to find the best speed. Here the Lynxmotion Sequencer comes in handy, because it can vary the playback speed of a motion as you play it back in realtime with a slider,
regards
noDNA