After a period of will we / won’t we, we just couldn’t resist putting ourselves forward for another edition of Pi Wars. The application is in and if accepted it would be the clubs 4th entry to the competition. More in hope than expectation the planning of the new robot has begun with the now traditional cardboard prototype whilst we settle on the shape and size for the new robot before starting to construct the chassis.

Having kept a few cardboard boxes around from various deliveries the first job was to measure the internal components that we were going to reuse from the last robot so that card versions of them could be created. The parts that we are reusing are the two motors, motor controller, motor battery, Pi power pack and the Raspberry Pi 3.

The width, height and depth was measured for each component and then the dimensions were drawn onto the cardboard, cut out and then taped together to create the cardboard versions. Now we could play around with different configurations to find the layout that worked the best before producing the chassis prototype.

There were some aspects of the previous bot designs that we felt had really worked well, like having two drive wheels at the front and a central rear omniwheel, the big wheels to give good ground clearance and to ensure that there is enough internal space to easily access the components inside.

One of the areas of concern last time was that we were very close to the maximum permitted robot width and this caused a few issues on some of the challenges. As such we were really keen on reducing the overall size of the robot as much as possible so we played around with a few configurations to try and achieve this.

This ultimately led to us looking at increasing the complexity of the robot a little by turning the motors through 90 degrees and then adding gears and a shaft to turn the drive back through 90 degrees to the wheels. This has let to the need to purchase some additional parts to achieve this and this is a bit of a risk as we have not tried to do this before.

To save space the internals will be split into 2 levels with the motors, drive shafts, motor controller and motor battery in the bottom compartment and the Pi and it’s battery on the top level for easy access. To see if this plan will work we need to await for the parts to be delivered first. In the meantime we plan to look at making improvements to the gun after it’s failure at the last Pi Wars.