In this tutorial i will show you how to make a rc rolling ball from an old rc car.You can upgrade it and make it similar to bb8 from star wars episode 8.My design is based on my funky imagination that got while daydreaming at class.
This build took me 2 days to completion and might cost you 10$(price depends on the rc car and lipo battery you bought).The body is made out of aluminium.Sorry for incomplete pics cause i wasn't actually planning to put this project into instructables.
By all means you can modify and give me some new suggestion.My goal is to make a cheap but cool gadget for kids to play.How can this magic thing roll??it use 2 motor as thruster thats hidden inside the ball :)
Step 1: Collecting Materials N Tools
1.Plenty of cables.
3.A plastic/metal ball(got mine from loccitane verbena ball) thx Ko steven for the ball :)
4.Lipo battery 3,7 v(don't forget charging station or charger).
6.Lego part that i don't know the name(pic will be shown)It looks like a wheel connector.
7.A few rubber bands.
8.Wheels(preferably rubber from you're rc car).
9.Dc motor (1,5v 2x)the common one.Try some tamiya motors it works better.
2.UHU glue/any strong glue.
3.A little tape.
4.Breadboard for testing motors.
Step 2: The Design
This is my design.I use 2 wheels that is attached to the ball side and use differential thrust as usual.I attach the pcb and battery and attach them together with rubber band b4 attaching the lego parts and wheel underneath the battery so it would roll when the ball roll.I also bent the antenna because the antenna is to long.
Try to make it as light as possible.Since i discovered that if its to heavy the ball might jiggle right to left.Optimum weight is around 50-150 gram.Btw don't forget to check the motors.
Step 3: Start Building the Outer Rim!!!
You can start by glueing a wheel to each side of the ball,make sure that the wheel is exactly on center.Then attach the dc motors onto each wheels.Add some wire to the dc motor and connect it to the pcb.
L and R(first motor)
F and B(second motor)
better to take pics as a reminder.
Step 4: MAKING THE ROLLING Mechanism
The rolling mechanism is pretty simple.I use a wheel as a rolling mechanism that holds the pcb and battery
So basically its: pcb on top(antenna bent a little cuz its to long)
battery at the middle(don't solder the connection since you might need to recharge)
the strange lego thing and the wheels.
Then i join them by using some rubber bands diagonally joined to improve the strength and stability of the rolling mechanism.
Step 5: Painting and Future Plans +conclusion
As usual you can paint any colour you want to,i recommend you use spray paint or acrylic paint for this project.I painted mine similar to cap america shield.You can also try painting it like bb8.Then make your own head using some magnets and little wheels.
Im actually genuinely surprised that it works so well.But the turning is so slow that it annoys me.Any suggestion will be appreciated.
Step 6: Done
Now you've successfully finish the rc ball project.