Hi Folks! I've been volunteering my time creating a very cheap emergency ventilator that squeezes a BVM (bag-valve-mask, aka ambu bag) to supply Covid-19 victims with air. I have a working prototype which you can see in the video at the bottom of the post. I come from a 3D printing background, so right now I'm controlling the stepper motor with a spare MKS SBase, smoothieware, and a few linesby playludesc - Controllers