Stepper motors are good for this. A stepper has the most torque at zero RPM and the torque falls as speed increases while a DC brushed motor has very little power when moving slowly. You need more gearing with the DC motor.
The problem is you need to generate precise pulses. If the pulse spacing is not accurate then you are asking a large telescope to accelerate and decelerate instantly. So to generat pulses need either 1) a hardware solution like a microcontroller or FPGA or pulse generator. 2) A real time kernel on the Linux system or 3) A PID loop to supervise a non-real-time software pulse generator When I build stuff, my preference is the microcontroller. I design it so the microcontroller can work independent of a larger Linux computer or take commands from a large Linux computer. I want some basic functionality when power is applied then adding the Linux PC adds more functionality. Linux CNC uses a slightly different idea they either go with Real-Time Linux or use a very simple pulse generator running in an FPGA. Reading up to three quadrature encoders with just a Raspberry Pi might work, or not. I don't know. A lot depends on the speed of the encoders. On Fri, Jul 10, 2020 at 6:45 PM R C <cjv...@gmail.com> wrote: > I don't think anyone did, but I know that's how most do it... > > But that's just too easy :) I would just like to see if I can do it, > killing time > > > On 7/10/20 7:39 PM, Ken Strauss wrote: > > I haven't been following this closely but has anyone suggested that you > use a > > DC motor with an encoder? With a PID loop and PWM power to the motor you > could > > run the motor continuously. DC motors with integrated encoder and > planetary > > gearbox are readily available for a few dollars. Just a thought. > > > > > > > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
