Bot-ception

Just a series of pictures I took while building the inner vector bot.

1/2″ sand ply and 1×4 pine
Hardware for one wheel assembly

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Getting the hub gear and the stepper motor gear to line up was taxing
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Finished wheel assembly
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“Finished vector bot

Here is a brief video showing how movement works with 3 wheels 120 degrees offset:

I will probably want to rebuild all of this when I get access to a CNC.

Dome Lighting

I wanted to do more with the dome lighting than what was shown in the movie. There, each array was made of 5 led’s and they didn’t do much. This was one spot where it’s “easy” to make it more interesting.

I purchased 100 2x5x7 mm LEDs. I knew they had a flange, but I could deal with that.  The openings in the dome are roughly 4×23 mm. So, I’d need to mount 11 LEDs in a row to fill the opening.

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2x5x7 mm LED showing flange
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Flangeless
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Removing the flange cleanly was a pain, so I removed every other flange before super gluing them to my fingertips.

Video: LED Array

After quite a bit of sanding, I was able to get them to fit snugly into the opening.

Video: Mounted LED

I decided to do something even more different with the rear opening. I stacked the LEDs in pairs before gluing them together.

Video: Different Array

After getting the coding done (a future post, I’m sure) this is the result: (I wish video did a better job at recording lights.

Where it all began

Like many people, when I saw the newest little astromech to join the Star Wars cast, I was very intrigued. Actually, that’s not the right word is it… The word is obsessed. Not obsessed in the way normal people get obsessed. I’m not buying every version of BB-8 I can find from plushies to stickers (full disclosure: I have a sticker on my laptop), I became interested in the physics behind the droid.

There are many builders creating versions of BB-8, but mine is slightly different.  Let’s go back a bit, shall we?

We all know that BB-8 was a practical effect in the movie.  GREAT! They actually did it!  But how? There seem to be 2 popular ways to build this droid. Axel drive vs Hamster ball.

Axel drive involves connecting a ballast to the shell or skeleton of a sphere and using motors to rotate the sphere along a single axis to generate movement.

Hamster drive uses (usually) a heavy two wheeled bot inside the sphere. by moving the hamster, you move the sphere.

I’ll be using a vector bot.  It uses three omni wheels pointing outward in 120 degree increments and can move in any direction at any time.  While it has similarities to hamster, I won’t need to turn or spin the bot inside the sphere to turn.

I’ll be posting more information and designs as I go.  But just wanted to start off the new build blog with my basic direction.

TLDR > 3 omni wheeled vector bot mounted inside a sphere