Hey all, I just wanted to jump in a little bit as I’m building a system that is very similar - and I have yet to find the perfect parts.
First, I bought two of the small peristaltic pumps off of ebay (6V DC motor driven, plastic housing, Link to Pump on Ebay). I tested them initially with an ajustable power supply (3V, 4.5V, 6V etc.) and found that they run well at a lower duty cycle (4.5V for example).
@james211 Here is a schematic of a simple circuit that I was using (via a 100k trimpot) to drive the motor slower. I also installed a 3-wire volt-meter to measure the number of volts that is being drawn across the motor. I’ve found that running it at normal (6V) setting is required to overcome the stall current, but once overcome you can drop the voltage by as much as 2 volts to run it at close to 50 rpm.
Apologies for the crappy looking schematic from LTSpice:
@Hootie81 I have a couple Nema17 Steppers lying around that I would love to stick a head onto, but I haven’t found any free-standing heads yet. I’ve also contacted a company about their stepper based peristaltic moters (Link to Technical Specs) and am awaiting a reply.
My aim is to have continuous flow as low as 0.16ml/min (10ml/hr).