We went on a Star Wars themed cruise, which meant getting BB-8 kitty-corner across the country. So (with the help of the 12 week old kitten), we packed him in a box:
"Inferno" the Kitten helping Pack BB-8
Lego BB-8 trying out his box, not so sure about this
After a surprisingly short flight to Orlando, he popped out on the belt at the other end:
Lego BB-8, hey dude's, the arrow points "UP"
Ominous TSA Inspected tape, uh oh.
TSA apparently didn't like the Battery + Phone + Wires connected to LEDs embedded in the plastic walls of his head. Unfortunately they weren't terribly careful getting into him to figure out what was up. They didn't know how to get the ball apart, and then dumped the head on it's side instead of carefully nested in the ball :(
TSA didn't know how to get the top panel off, so all the panels got split
And head kinda demolished
BB-8's head after the TSA got done with it
Don't get me wrong, I totally get why the TSA would need to look at him, but I'm a bit bummed about the lack of care. I realize they're probably in a hurry and stuff, but I'm glad it wasn't something like a Ming Vase. But I don't think I'll be sending them Christmas cards this year.
Anyhoo, he's all better now, I'll post pix from the cruise next...
After my last testing, someone more rational than I suggested "he looks pretty good, why not stop with a static droid?" or maybe I "like the mess."
Being less balanced myself, I confess I found myself somewhat at a loss to how to respond to that remark
I guess it's kind of like climbing Everest. I'm at base camp and I'd really like to get to the summit. It may prove impossible (more impossible?) but I've made it this far, so I have to try...
(FWIW, the mess isn't as bad as it looks, "only" 3 of the panels fell off (ok, half the sphere), but the panels stayed mostly intact and it took 20 minutes or so to reassemble.)
For those questioning my sanity, this isn't even the hard part. I'm not at all concerned that I'll be able to get the sphere to roll.
The first roll test showed that the sphere is "round enough" (& stable enough when it gets Kragle'd).
This second test, short though it was, demonstrated that an axle centered on the triangles should be aesthetically pleasing. Three panels fell apart, but without most of the internal structure expected to support the final model that isn't surprising. (He needs more 3D printed panels, and, of course, the Kragle!)
Where I'm afraid the obstacles may become insurmountable is getting the head to smoothly slide over the dome. THAT's going to be the hard part!
I have a fallback plan to make him approachable even if that fails. I also suspect that even if the rolling ball works, he's likely going to be limited by terrain and in speed. L3-G0 placed 3rd in a race, I don't think Lego BB-8 is going to do that!
In my previous post, What's the best way to roll?, I discussed an intriguing alternative to the "hamster" model. That seems like a pretty promising technique, but is a driveshaft going to "look right"? Are the 123/456 triangle centers an acceptable point for the center?
Clearly some orientations are bad. If the panel rings are in the center, then it'd be pretty obvious that two rings were always on the outside while the others chased each other in circles. That might be an effect, but it's not the random looking behavior of the movie.
With the driveshaft ends in the middle of a triangle, it'd kind of alternate which side the panel was traveling up under the dome and look less regular and the motion would seem more naturally organic... In theory at least, but would Lego BB-8 look OK that way?
One way to find out, spin the sphere and see what happens. Unlike the roll test I decided to hold it and make it steadier.
BB-8 says "Ack, More Tests!!!!"
That didn't quite work out.
3 of the panels fell off (that sounds better than saying "half the sphere fell apart"), but the test showed, I think, that this axis of rotation is pretty good. I was going to attempt to rock it a bit as it would when turning, but I think the few seconds of rotation showed that the pattern doesn't look particularly regular, even though it is.
So, it's a go! Depending on alignment with the panels/Lego I might make it a little off-center from the triangle, but I think this will look good enough!
The builders have "standardized" on a system of labeling the panels so that we can discuss them. As there are 6 panels, I suggested numbering them like the faces of a die, and this is what we ended up with.
BB-8 Hatch Nomenclature - Panel image courtesy of TinyP
There's also a "top", "bottom", etc. system that I find confusing since he is, after all, a sphere, where each of those could become any other....
Now that the static model is kinda working and we proved that he can roll, HOW should he roll?
In "How Do I Make Him Drive" I discussed a few options, however since then another has revealed itself. If you watch the Star Wars Celebration: Anaheim BB-8 roll-out video closely, you may notice that he pretty much rolls around the same axis the entire time. That's interesting. There's another way to make a ball roll.
What I think they did (and pointed out by the BB-8 Builder's Club) is to have a "driveshaft" that runs between two points on the sphere. That makes him run in a straight line. To turn, there's a flywheel, likely hanging below the driveshaft as low as possible. Conservation of Angular Momentum means that when the flywheel is spun rapidly in one direction, the sphere has to rotate in the other direction. Together the movement is pretty natural.
BB-8 on Stage at Star Wars Celebration Anaheim
The endpoints of his rotation axis appear to be in the middle, or close to the middle of the white "triangles" between what we builders have labeled the 1-2-3 panel rings and the 4-5-6 rings. (That numbering scheme is a coincidence, I was thinking of dice and the orientation is pure luck, but easy to remember.)
Furthermore, folks had notice an interesting ring on the model where it looks like there's a round access or construction mark. That ring surrounds the 1-2-3 triangle. Not sure if it's related to the driveshaft, but seems likely that there's something interesting to cause it.
Ring on Celebration BB-8 Stage Model
So I think what might work best is to have a "driveshaft" between the two triangle panels. There's a video of model doing this on YouTube.
That technique solves a lot of concerns about my build. The interior was intended to be smooth to allow a "hamster" to roam, but with a driveshaft it doesn't have to be as particular. In addition, it allows for simplified wiring and placement of the LEDs... Eventually maybe even room for some of the toys in the hatch panels?
Anyway, that's what I'll investigate in the future.
BB-8 isn't too happy about this next video. We're trying to make sure the sphere concept is sound before we add the motors & everything, so here goes....
