The biggest problem with making a Lego version of the Star Wars BB8 droid is the round shell: there is no spherical LEGO part that is large enough to contain a motor, a battery box and the infra-red receiver. Purists, please look away now, for I have committed a sin: the shell is not a LEGO piece, but is a two-plastic sphere. basically, a giant Christmas bauble.
Here is my second attempt at BB8. The weight distribution is too high, and the mechanism flips over quite a bit. So back to the drawing board…
… and here is version 3: the wheels are further apart, and the centre of gravity is lower. I also added four “boat weights” to improve stability.
in the meantime, a fellow Brit is also working on a Lego BB8. His version has a ball made of Lego Technic parts. See https://ideas.lego.com/projects/126131/updates and http://www.brickshelf.com/cgi-bin/gallery.cgi?m=mbellis
It is possible to use a genuine LEGO sphere – as seen in this video – but there isn’t enough space inside for the Lego power functions components.
Someone else has worked out how to do the head with magnets – http://lego.gizmodo.com/someone-figured-out-how-to-build-a-tiny-rolling-bb-8-us-1761492071. That was my plan for the head too, but I can no longer prove it, and I haven’t got that far. However, their version only rolls forwards.
The quest continues to find a LEGO set that can be easily converted to remote control. In a moment of tidying up, I re-discovered this bulldozer (Dozer set 7685) in the corner of my study. A prime candidate to try adding motors and an SBrick.
This bulldozer set is not supplied with motors, and has no instructiors for adding them. But there is lots of space internally. I rebuilt it a few times, added two M-motors, a few gears, a battery box and the SBrick. Staying true to the original model was quite a challenge. The tracks are now half a stud further out than in the original model, and the plough-arms at the sides only just miss the tracks.
The remote control equipment in the Power Functions range uses infra-red, and therefore isn’t technically “radio” control. It offers limited control – basically forwards and backwards at full speed. The SBrick permits finer motor speed control, uses Bluetooth instead of infra-red, and is controlled from a smartphone. Up to four motors can be controlled at once, though only two are used for this model.
More details of the drive mechanism, the build, the SBrick interface and the challenges in building this model will follow in future posts. Please let me know what you are interested in (in the comments below) and I’ll do my best to answer.
This is the first attempt at the clock face for my Lego clock. The V and X numbers are made using “cheeses” (1×1 with slope). I only had 4 in black, so most of them are “black-transparent” or “blue transparent”. I ran out of white, hence a few in tan. I also ran out of white 1×2 plates.
There is some debate regarding the correct representation of 4. Apparently IV is a Victorian addition, and old clocks used IIII instead.