Friday, 11 November 2016

Robot Car V2.0

Robot Car V2.0

  A few weeks ago, we created the first version of our new and slowly improving robot car. For version 2 we added the front wheels, the body and a relay to control both sides from a single 9v battery.

  Continuining from the back of a "beer mat" design below we continued to implement.

Initial Design
Our parts list can be found here

  The first task to do was to re-cut and bend the wheel brackets, this aluminium was to be 11.5cm in length. The width was 2cm and each needed a hole drilling to allow the gears wheel connector to poke through and allow the wheel itself to sit on it.

  Once this was achieved we drilled out the rivets attaching the two wheels together from V1.0 and attached them to the larger frame using more rivets.

Lesson 1: Make sure you have measured the rivet locations correctly or you will have wonky wheels
   At this point we wanted to be able to thread the motor wires to the upper body to attach to the relay/battery etc. To do this we drilled two holes either side of the frame and attached grommets to them before threading through the motor wires - two to a side.

Lesson 2: Loose wires on a flimsy motor will easily break. SECURE them
  As can be seen in lesson 2. The wires being loose underneath the frame caused them to turn and pull whilst manoeuvring them. This lead to the wires coming off the motors and needing urgent soldering surgery. To secure them, we have now added cable ties that attach the wires tort at the base of the motor.

  Once the wires were threaded through we attached we placed the relay on the frame on top of a piece of cardboard to reduce the chances of the relay etc. shorting out.

Ready to wire
  For V2.0 we decided we would just directly connect the motors to the relays switches as well as the battery. The wiring system we chose can be seen in the image below. We are currently researching a system diagram creator (software). Any suggestions would be greatly appreciated!

Current confusing wiring diagram - wired connectors between NC and NO

  As you can see/not see in the diagram above, red wires show positive energy flow, black wired show ground and the blue wires are just connectors. The blue boxes are motors, yellow box is battery, the centre grey circle is a wire connector and the orange box is the relay module with the grey boxes inside being each switch.

  It's quite obvious that this form of drawing diagrams is going to be quickly untenable. But we live and learn.
Tidy and Smart wiring
  This wiring allows the robot to go in a straight line. With slight moving of wires you can make the car go in a circle but I'll leave you to play to make that happen. Below is a video of the robot in motion. We move onwards.
In Action:

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