This is more of a 'mechanical' question about the torque available in a stepper motor, I hope someone can help a little.
A while ago I created a 'dosing' pump using a timeswitch as a cam driver for a syringe with an arrangement of one-way valves so that on one half of the rotation it filled the syringes and on the other half it emptied them.
The photo shows a 'twin' model I played with, but there was not enough torque in the drive mechanism, so the final version just used a single syringe.
It worked fine for a couple of months but eventually the torque was too much for the plastic gearing.
I had previously thought of using a geared ac/dc motor with some sort of cam/switch/sensor to count the revolutions but that seemed a bit messy.
It's just occured to me that maybe I could use a stepper motor instead, driven from a picaxe, but I have no idea of the torque or what to look for in a stepper motor so any suggestions would be useful.
Cheers
Chris
A while ago I created a 'dosing' pump using a timeswitch as a cam driver for a syringe with an arrangement of one-way valves so that on one half of the rotation it filled the syringes and on the other half it emptied them.
The photo shows a 'twin' model I played with, but there was not enough torque in the drive mechanism, so the final version just used a single syringe.
It worked fine for a couple of months but eventually the torque was too much for the plastic gearing.
I had previously thought of using a geared ac/dc motor with some sort of cam/switch/sensor to count the revolutions but that seemed a bit messy.
It's just occured to me that maybe I could use a stepper motor instead, driven from a picaxe, but I have no idea of the torque or what to look for in a stepper motor so any suggestions would be useful.
Cheers
Chris