Originally shared by Nathaniel Stenzel
What do you guys think about the idea of using a brushless DC motor or a stepper motor that has a low number of steps per resolution in a screw drive linear motion system?
A lot depends on what kind of speed and accuracy you want. The stepper motor will give you lower speed but higher precision.
I am using high torque / low speed brushless motors with hall effect sensors to drive a ballscrew.
This gives me a fast, strong, efficient linear drive with the hall effect sensors doubling as a 3 phase quadrature encoder.
Depending on what you want to do with it you may need to build a custom motor driver.
Try to find a driver for a 3 phase stepper motor because it will have current regulation built in.
Most screwdrivers use brushed motors because of its low cost. Brushless motors are definitely a better (but more expensive) choice that will last much longer.
I’d use a servo
@Russell_Cameron You use a slow motor and a ballscrew and get fast motion? How the???
@NathanielStenzel Fast is relative. When I first looked at linear motors that could handle a 40Kg load, most had a speed of something like 20mm a second. These linear actuators tend to have a 12V brushed motor that drives a gearbox and finally a ball screw.
The brushless motor I use is only rated for 1000 rpm but has an output torque of about 6Kg.cm (without any gearbox). Combined with a 1204 ball screw (12mm diameter, 4mm pitch) I get in excess of 40Kg force and a speed in excess of 60mm a second.
Because the ball screw has virtually no backlash and I do not use any gearbox the positioning is very precise. The motors hall effect sensors when used as an encoder give me 24 steps per revolution which equals 0.166mm with the 1204 ball screw.
@Russell_Cameron I guess I saw slow and overlooked that it was a brushless motor. Those are much much faster than the stepper motors that I am used to.