noodleFeet : All Wired and Ready

When your baby is learning to walk, you make sure its near soft things and away from stairs so that when the inevitable fall occurs, they don’t collapse into pieces. When your baby is a robot learning to walk, bungie chords and harnesses are also needed. And in the case with noodle, who is delicate and wobbly like a skittish baby fawn, I am sparing no precaution!

The noodle Harness

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Robots get rigging. Mark took the time this weekend and installed a guide wire on the ceiling over our work table. A “leash” hangs down from this wire and clips on to noodle’s smashing neon-yellow harness which wraps around all four of his legs. If he loses his balance, he won’t have very far to fall before the leash pulls tight and catches him.

Calibration!

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Before assembling noodle for his big day, I had to calibrate all of the servo motors to 90º. Only then could I screw the gears to the motor shafts, as well as connect the pulley bits from the secondary servo motors on each leg to the bendy bits.

In the end, once all of the final parts were attached to one another,  I was pleased with how solidly he stands on his own. Hopefully I can figure out the right way to distribute balance so that he can lift up his feet and walk.

Wiring up the Bread

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Lastly, this afternoon I taped an Arduino down to the end of a breadboard and fashioned some male headers so that the servo motors could easily plug-in and tether to their appropriate pins. The breadboard itself is taped directly to the leash so that it will move with noodle as he walks… or falls.

When is he walking?

So, he’s poised and ready. The big moment will either come tonight some time or tomorrow after Mark is home from work for the weekend. Either way, I’ll be sure to take LOTS of footage of my wobbly child as he navigates across the table for the first time. =O

Wish us luck!

noodleFeet : Goes Metal

I’ve relied on 3D printing for so many of my prototypes lately, and have finally come to a point where plastic won’t cut it any longer. I require metal, in this case aluminum. The likes of which I ordered from McMaster-Carr and received in the mail last week. I literally spent the majority of the weekend meditating over how to measure my cuts and holes… as for the first time in a long time, their accuracy and placement was entirely up to me and my calipers, not some Cartesian goo plotter as I’m so spoiled by…

While everyone was downing beer and watching the Stuperbowl, I was in the garage with Mark playing with his father’s ancient drill press. He eyeballed one axis, I checked it against the other, and we were able to punch the 24 holes needed on the four pieces of aluminum tubing which would soon be noodleFeet’s strong new legs.

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As you can see, I printed out little strips of paper with lines where holes needed to be drilled. It only occurred to us immediately after we finished how much easier this would have been if we had 3D printed a jig for drilling the holes instead… So alas, 3D printing could have potentially saved the day. Thoughtful or not… we did a pretty good job.

Once the aluminum femur was assembled, I realized I was going to need stronger springs. These flour legs are going to support eight motors, a board, and eyeballs; a decent amount of weight:

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The calf bit is essentially a bone buried within the noodle material. However, with my last prototype, the bone kept sliding out the clearance slot I cut in the noodle. So to remedy this I made these little braces that look like pac-man heads… which keep the bone centered within the tube and prevent it from popping out where it isn’t suppose to:

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The rare and beautiful white noodle was harvested by Mark from the great noodle beast itself. I cut the pieces to length with a Japanese saw and carved the appropriate clearance slots so that the legs can fold in on themselves like they should:

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The new servo and leg bracket is THICK. It is complete with roller bearings spaced a decent amount apart vertically to keep the intersecting pipe from wobbling around (as with my first prototype):

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The eight roller bearings hold the pipes perfectly parallel to one another and allow them to turn nice and smoothly. I also added stronger springs to tension the legs outward, so the new prototype is a little monster. Although… he looks sort of helpless up-side-down on my bench right now:

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At this point, Feet is nothing but a pile of feet. He needs eyes, and that is exactly what I’m going to do next… and maybe a brain. Over this weekend I’ll likely hook an Arduino up to his servos and figure out a walking pattern too.

I honestly have no idea what it’ll look like when he walks, but I’m hoping due to the springs counterbalancing his weight that he’ll have a little bit of a bounce. That’d be cute.

I also don’t know if he’ll be able to balance himself when he walks. Once summer happens and the noodle is less rare, I will go harvest some 4″ stock (in neon yellow) from Walmart and cut my prototype some new fat feet. That way he makes more contact with the ground and is less like to fall. Like training feet.

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Hopefully by my next update he’ll be moving some… like a robot aught to. Cheers!