End effector
I asked my instructor Þórarinn whether he could show me how to make an electromagnet, so that baks the robot arm could pick up small metal things. I expected to need to find a suitable iron core and wrap copper wire around it, and that it would be a half-day thing. I had no idea it could be a 5 minute thing!
Þórarinn got a choke coil from the electronics inventory, tried a few different voltage and current combinations, and voilá! We can lift a small bearing ball!
Then we tried soldering three choke coils together to see if the holding strength would increase:
It did, you can't shake the ball off! But the current requirements might be too high for a USB port-powered robot.