At the February Cambridge Raspberry Pi we spoke to Tim Freeburn from PiBorg about his latest monstrosity:
Can you tell us what’s hooked up to a Raspberry Pi that makes it the DoodleBorg?
[DoodleBorg is] running off six motorcycle starter motors. It’s using mini all-terrain vehicle wheels and has a custom chassis made out of six-millimetre thick steel that has been laser cut. It has two motorcycle batteries, and six of our wonderful PicoBorg reverse control boards which are capable of five amps per channel, ten amps in total. We’ve got them connected up, one per motor so we can individually control each of the wheels. This means we can make alternate wheels go in all sorts of directions if we want them to. There are some big crazy switches on the front that serve emergency power-offs too.
How powerful is the DoodleBorg?
It can do 30 miles an hour, although it’s not actually geared for speed – it’s geared for torque. So what [we have for it is] a tow ball attachment to go on the top of it. With that what we can do is pull a trailer, caravan, boat or something like that. We can drive it around and manoeuvre it into difficult- to-get-to spots in your back garden.
How is it controlled right now?
At the moment, we’re showing it off with a PlayStation controller,
connected over Bluetooth. We have autonomous software so it will control itself, and we have additional boards that we can use to make it navigate a certain direction; for example, keep going south. We’ll be adding cameras and sensors in the coming weeks and making this a fully autonomous robot.
How much torque does it generate?
They’re 19-amp motors, 24 volts. So their maximum theoretical varies at 2.1 KW – which is approximately three horsepower. That should be about enough to pull a caravan.
Will this just be a hobby project, or do you plan to sell it as a kit?
It would probably be a bit expensive as a kit, although we can build them if someone wants. This has cost us probably over £1,000. [Which is probably not all that much once you’ve taken into account] all the laser cut and the size of the bearings there. It is fairly bulletproof, though. While we won’t be selling the robot itself as a kit, we are definitely selling the little PicoBorg reverse boards.
When will these PicoBorgs be available for sale?
[They’re available for sale right now from the PiBorg website]. This board will control small motors, it will control stepper motors, it will control big motors. They’re all forwards and reverse with VWMs – speed control. Also, you can keep stacking them up, so you can add an extra axis, an extra motor, an extra anything. So, for example, CNC machines you might have two stepper motors to get your XY stage, and then have one for heat and that sort of thing. It’s very scalable.
How much interest has the DoodleBorg got?
Lots of interest; [at the February CamJam] it appealed to both the kids and adults. I think DoodleBorg can be a little intimidating but once you get above a certain height, it’s probably okay, and then there’s more interest in this. But we’ve certainly had a lot of people playing with the little PiCy packs.
What’s in the future for PiBorg?
In the future we do have some things coming up, at the moment we have a PicoBorg, which is an inexpensive on-off switch. The PicoBorg Reverse is the more expensive version. We have the XLoBorg, which is an accelerometer and magnetometer that you can use as a compass. We have LedBorg, an RGB LED, and that’s a great way to learn how to do some further set up on the Raspberry Pi. And we also have our TriBorg which all of these mount on. We’re basically moving at the movement to doing purely just Raspberry Pi products – and potentially some Arduino-based control things in the future.