06. Temporary plastic spoons attachment

If anybody wondered – the spoons were attached using two screws and two rubber bands, as in the pictures below:

Surprisingly, this was very nice setup and I even considered having it fixed for good, but, as you will see in next posts, this was eventually just temporary solution. Just enough for testing the drive.

05. Wheels and battery attachment and the first test drive!

After collecting the item and creating “modules” from the excavator toy I started combining them to the wooden stick core. Original idea was to screw it but zip ties turned out to be much easier and better option. Battery pack:

To attach the wheels, which had irregular black housings, I cut and added additional piece of wood:

When I had these ready I soldered wheels before fixing them onto construction and got the following:

And eventually attached the wheels using zip ties and adding some screws to keep them firmly in place:

At this point I figured I kept forgetting where is the front/back and left/right side of the mechanism so I written initial on the bottom of the stick for the directions (P=right).

At this point I really wanted to do the first drive so… Using rubber bands, I attached temporarily plastic spoons to keep it in the upright position and went for it!

I was really surprised that it was working quite fine from the very beginning and the plastic spoons were actually a very decent idea as they are smooth and slide nicely and also, as these are from thin plastic, give some level of suspension.

04. RC excavator toy disintegration

Once I got my hands on the toy I just played with it a little and then started the process of shredding it into pieces.

After a while I had following components:

Battery pack, which I will use with rechargeable AA batteries:

Base for the head rotation magnet platform – I will cut off only the round mechanism and base for the engine so it can fit nicely into the sphere just under the head dome:

The top of that part I already cut off the base of the toy. You can also see the original wheels for the caterpillar drive mechanism (without engines and main wheels):

Wheels were bare yellow plastic with sharp “teeth” like in a cogwheel so, as not to scratch the inside of the styrofoam ball, I cut and glued pieces of the soft rubber from caterpillar around them:

I had to unsolder wheels as the cables were running inside of the rotation mechanism of the cabin. To make sure I do not mix the cabling I made notes with a pencil on the engines with colors (Y=yellow, B=blue, etc.).

And finally, the “heart” of the toy – you can see the metal rectangular antenna, lightning (which was not needed so I left only one LED to know if its powered on), engine for the rotation, another engine for the shovel (also removed as not needed) and cabling for the battery pack and base engines:

Of course, I want to make the replica as close to original as possible so eventually there WILL BE lightning in the body and in the head but these will be organized independently from the movement mechanism.

03. Internal mechanism

For the mechanism, as I am no engineer and have no electronics background, I wanted to use a complete solution which would need as little modification as possible.

This is one of the reasons why I did not go with the Arduino solution.

I found out that an RC toy using two engines as its movement controllers would be perfect (I was thinking about a tank on caterpillars). I could not find any (all of them were running on 4 wheels with “steering wheels” in front while I needed steering based on the left/right differentials).

I eventually found an excavator on caterpillars which were running with the mechanism I was looking for and with extra, rotating cabin! I now had the engine for rotation of the BB-8’s head.


There is also a 4th engine for the movement of the shovel which I could use for the up/down head movement but I think there will not be enough space inside of the body to fix it and I do not have any idea how to design that mechanism as yet.

For now, I will just stick to the simple movement of the body and rotation of the head.

02. First steps

The first step I took was to find hollow balls which could be filled with the electronics for movement, sounds and lights. I did not want to go with the “classic” approach of gluing several layers of paper on a beach ball as it seemed to complex and not too perfect in the end.

I was looking for paper/carton balls but could not find anything in the size I wanted (at least 30cm for the body) but I eventually stumbled upon a styrofoam balls. I bought 30cm ball for the body and 20cm for the head (I really don’t like naming it a “dome” for some weird reason). I am fully aware that the original relation is not perfect (as the head should be some 17-18cm) but I hope it is going to be fine enough in the end.

The same shop I was ordering the styrofoam balls had also wonderful 60mm transparent christmas tree balls so I did not have to think twice to order one to be used as the big “radar eye”.

I browsed the store and also found a nice round holder which will be used to keep the final BB-8 in place when not in use.

I already had saved a wooden stick a while ago (it was element of a washing machine package – I knew I could use it one day!) and I will use it as the base “core” of the internal mechanisms by attaching all the electronics, batteries and engines to it.

01. The first idea

This webpage is going to be a record of all the steps I took to build my own, “alive” replica of the Star Wars’ BB-8 droid.

I was inspired by the DIY BB-8 video on YouTube by Techbuilder:

The tricky part is that I am not an engineer and I do not have any background in electronics – just some general knowledge that any random guy has.

It took me a while to figure out my general idea for the design and eventually I figured the easiest way to create my BB-8 is to buy hollow Styrofoam balls (30cm body and 20cm head) and for the mechanism use some engines and remote from an RC-toy. I got the RC-excavator with 4 engines for ~$20 while all Arduino components would be much more expensive, also, I have no background in electronics/programming so it would not be that much fun with Arduino anyway as I would have to use complete solutions downloaded from the Internet. I want to have this as “personal” as I can :)

As I had a lot of work at the time when I got impressed about the general idea, it took a while to eventually start collecting the elements and actually starting building something.

In the beginning I was looking for a paper ball but I could not find any so I searched for styrofoam ones and I found them in an online shop with decorative materials. They also had a very nice hollow, transparent 60mm christmas tree balls which I will use for the “eye” of BB-8. I know most people do the paper mache ball based on the beach ball but I see that in most cases they are not perfectly spherical – I did not like it and wanted to go with another solution.

I guess this would be enough for the starters. More info and pictures to come in next posts :)