Toshiba Stepper Motor Drivers For Mac ((TOP))
Ideally, you need the driver to be capable of running your stepper motor without any excess heating or noise. You also don't want to overbuy with an expensive stepper driver when you are running a relatively small stepper motor.
Toshiba Stepper Motor Drivers For Mac
It can also run smaller NEMA 17 motors with a current rating of up to 1.5A. Although I don't recommend it. As a rule of thumb, you should ideally buy a stepper drive that has a rated current that is 1.4 times the rated current of the stepper motor.
The TMC2209 is an ultra-quiet two-phase stepper motor driver chip with a continuous drive current of 2A and a peak current of 2.8A. Compared to the TMC2208, the drive current is improved by 0.6A--0.8A, while the Blockage increases the stall detection function.
In a hybrid stepper motor, a microstepping-enabled motor driver will adjust the current in the stator coils to position the permanent magnet rotor in an intermediate position between two subsequent full-steps. A full-step is then divided into a number of microsteps, and each microstep is achieved by the two coil currents.
Many older industrial motor drivers feature only 4 microsteps (quarter-step mode), but today, 16, 32 and even 256 microsteps per full-step are commonly found. If we had a 200 steps per revolution stepper motor before, we now have a 51,200 steps per revolution miracle. In theory.
So, does this theory apply? And do all microstep motor drivers deliver the same performance in terms of microstep positioning accuracy? I recently had the chance to test a few motor drivers for a project, and I was rather surprised by the results.
The Texas Instruments DRV8825 on a Pololu-like stepper driver breakout board performed the worst. I repeated the measurement several times with different breakout boards from different sources, all of them resulted in curves almost identical to this one. However, since the driver is capable of supplying a higher current of 2.2 A to the motor, it shows a significantly smaller deflection under load at the full-step and half-step positions.
However, small and light applications with low load and low friction may indeed resort to microstepping as a cheap trick to squeeze more accuracy out of a standard stepper motor. Even with a cheap, low-current motor driver, looking at the very well performing A4988, accurate angular positioning is possible, as long as the load is kept low, ideally within the incremental torque of a microstep.
It looks like you used different current settings for each of the drivers. Usually a stepper will perform significantly better when its maximum current (without saturation) is matched to the driver. This (from experience) can then be tweaked for either more torque or more accuracy, but usually It is a trade off one for the other.
Voltage improves stepper max speed because it shortens the coil charging time. This test was done at 0rpm so it should not be a game changer here. Current adjustment, however will definitely impact deflection with the same motor and load.
Very nice. Something I always consider when microstepping is that you need to maintain full power to hold position. Some applications like to move the motor, then power off. A stepper will cog to the nearest full step if you used microstepping to get to position. It is advantageous to be able to move and power off in applications where heat dissipated by the motor is an issue (like precision optical instrumentation). For some reason nearly everything I build with steppers only powers up the motor when moving and powers down on reaching the target.
Pretty interesting. Makes me want to do a DIY controller with current amps and14 bit DACs and see what happens if you calibrate and keep a current table. Also makes that project with the encoder on the stepper motor look even more interesting. Huston instruments small plotters used steppers. HP small plotters used DC motors and encoders and they were mush faster and more precise. A convenient closed loop on a good affordable motor is going to be a break-out product one of these days.
Nice article, very well explained. Nowadays it is kind of easy and affordable to use field oriented control with steppers. The result is a high performance servo drive with high torque due to the stepper design. The only thing you need is a cheap encoder (magnetic for example) and some microprocessor running the foc algorithm. Hook it up to a bunch of drivers (one for each coil) and enjoy a great solution.
In the company I work for, I have been developing a stepper motor driver (from scratch) for a while. To bad I cannot make it open source, as I would really like that. In that project from the very beggining I am using linear pr rotarry encpders with stepper motors. My alghoritm doesnt even have open loop functionality workng yet, as we havent used it so far for anything. Thats the reason why I was so suprised that so many people in the community use open loop- for instance I never had a problem with steps loosing or position loosing, the PID corrects everything. You say closed loop is more complex, but when you look at this from another level, like what are the cons and advantages in the end, then it is more difficult to make a working open loop system.