The first batch of parts has arrived for the linear delta robot. I’ve chosen to base the electronics around an Arduino and some really neat A4988 stepper motor breakout boards from Pololu. Quite incredible that for such a small package they can deliver a supposed 2A at 35V. They also support up to x16 micro-stepping allowing 3200 steps per-revolution from a typical 200 steps-per-revolution bipolar stepper motor.
For the joints that connect the vertically moving carriages to the plotting head I’ve chosen to use some reasonable priced ball joints from RS Electronics (a mere £2 a pop). They come dis-assembled which was a great opportunity to use my Dads treadle powered press for some production line fun.
And here are the assembled joints.