Software suggestions and requests

[DoulosDS]

Peristaltic Pump Amazon.JPG Found this pump on Amazon for $12, free shipping. I was thinking I would need to replace the motor with a stepper, but I don't think that's necessary. I can add an optical sensor to detect the rotor arms as they pass (looks like there are 3). The software can count them and run the motor forward and reverse as needed to adjust the resin level. If the flow rate and RPM specs are accurate, it should transfer 0.2 ml per 1/3 revolution. Conveniently, that is the same volume I calculated for Z-axis error due to tube pinch displacement in my previous post. So, if the print tank is approximately 3" in diameter or 75 mm, the area is 4418 mm2, and 1/3 rotation of the pump results in a Z-axis increment of 0.0456 mm. That's not great resolution, but it means the maximum resin level adjustment rate is only 13.5 mm/min or 0.228 mm/sec. I think that a second pump could run in parallel with this one, maybe with a higher flow rate. Both pumps could pump extra brine to overcome resin surface tension and viscosity issues, ensuring all the previous layer is covered with fresh, liquid resin. Then remove all but the increase for the current slice, within a few seconds.