I don’t have a good track record with mechanical projects – anything that moves. I do much better with purely electrical devices. As soon as you have moving parts you have to deal with things like friction, backlash, wear, tolerances, inductive spikes… I don’t like any of those things. Every couple of years I forget this and think it’ll be different this time, so here is another mechanical project.
A couple of years ago while still at university I started a balancing robot project. I quickly gave up. The reason was that my robot was free standing and balanced on two wheels. There were a number of issues:
- The robot would run around and I didn’t have enough space of my desk to allow it to balance
- The programming cable would restrain the robot so I also had to unplug my programming cable each time I wanted to test it – not ideal for quick iteration
- It was hard to control the environment and get the motors aligned
- The robot could not have an external power source so had to rely on batteries
This time I am still going for a balancing robot but I am going for a rotational robot, rather than a free standing robot.
A “sketch” (Sketchy drawing)
Continue reading “Project: SpinBalance – Introduction”
The robot box needs to know when it has reached the limit of it’s motion. If motion continues past this point, the machine will literally rip itself apart. To stop this happening, I am using a limit switch that will be pressed if the robotic finger move too far. However, it seemed that a good portion of the time the robot would ignore this button and continue to rip itself apart. The reason for this lies in the way I was using interrupts to detect the pressing of the button.
Continue reading “Project: Robox – Buttons: Interrupts or Polling?”
In my previous post I talked about modifying the gearbox of a continuous servo motor so that it span faster, albeit with lower torque. Since then I have been fighting with a new issue that was proving to be a show stopper. The issue is demonstrated in this video:
Continue reading “Project: Robox – Servo Temperature Drift”
I needed a servo for the robotic finger so that it could go forwards and backwards in a controlled manner to push the switches. Servos normally have limited rotation e.g. 180 degrees but I accidentally ordered a continuous servo which means that the motor spins continuously and instead of controlling the angle of the motor, you control the speed of rotation. This is obviously not OK because I would not be able to move the finger reliably. However I realised that it was well suited to the motor driving the threaded rod.
Continue reading “Project: Robox – Modifying Servo”
Have you ever seen the “useless machine” robots that everyone makes. It’s just a box with a switch, and when you flick the switch, a robot arm pops out of the box and flicks it back – useless, hence the name.
Well I wanted to take it one step further.
Continue reading “Project: Robox – Beginning”