The difference between 0.9 and 1.8 degree step size

On my Prusa Mendel RepRap I have nema 17 stepper motors. I get them off Ebay, straight from the factory. Like something out of Home Improvement, I went a little over the top and got steppers that are a tad overpowered for 3D printing. But, I love them, they barely break a sweat or heat up even after hours of printing.

Stepper motors are a little different from most electric motors. Rather than just spin, they have the ability to ‘step’ and perform fairly accurate partial rotations. These steps make it very easy to tell your stepper motor to rotate say only 7.2°. This is really important for 3D printing, as a big element of 3D printing is just about making lots of these small, precise movements.


The super power Wantai stepper motors that I run on my RepRap can make 200 steps in a single rotation, this means the smallest rotation they can possible do is 1.8°. I found some other stepper motors that can do a massive 400 steps a rotation, and got me wondering. If I upgraded my stepper motors, will I notice much of an improvement in print accuracy and quality? So I fired off a question to the now defunct Makers Stackexchange. Soon after, the awesome Adam Davis replied with the following answer.

The Answer:
The tradeoff, mechanically, between the two resolutions is typically a small decrease in torque due to the way stepper motors are designed.  You can compensate with higher currents or larger motors if needed.  You also need to double the speed of your driver to maintain the same machine speed if you go with a finer resolution stepper.  Check out and compare the motor specifications to see this effect as you move from one resolution to another in the same size motor package.

Further, current electronics packages and firmware tend to be designed for lower resolution, faster machines.  As such there are reports that you can only go up to 1/8 microstepping on the higher resolution steppers.  If you have 1/8 on the high resolution stepper, and 1/16 on the low resolution stepper, you end up with nearly the same effective resolution.

At this point in time the practical answer to the “will I get better/faster prints from a 0.9 degree stepper motor” is no.  If one costs less than the other, you might choose based on price.  If you are experimenting with high resolution, slow printing and you are writing your own controller firmware, then you might gain some benefit from the 0.9 degree steppers.

https://www.smore.com/20exh-the-basic-idea-of-electric-motors
http://lindada.freeblog.biz/2019/10/26/what-is-the-difference-between-a-stepper-motor-and-a-common-motor/

Mechanical components that complement gear motors

Stepper motor gearbox are composed of an electric motor and gears, which form the kinematic chain – the fundamental component of the gear ratio.

Kinematic chain
A motor’s speed reducer is composed of a speed reducer and its gears.

This speed reducer is basically a variable speed drive that allows for the speed to be reduced and increased at the output shaft.

Gears
Gears are toothed wheels made of metal or plastic (and new materials with each passing day) that transmit motion when meshing with each other.

They are defined by their number of teeth and their size. In addition, they may have straight-cut or helical teeth.

Do you want to know more about gears? Check out this post.

Motors
The five types of motors that see the most use in gear motors are:

Brushed motors, with brushes normally made out of carbon. They are bidirectional and may be used with DC or AC. They have a service life of about 3000 hours.
Asynchronous motors, which are brushless single-direction motors. They are highly limited.
Synchronous brushless motors, which may be single-direction or bidirectional. They have a constant speed if the frequency of the power source is stable.
Brushless DC motors that use a driver and can attain high speeds.
Stepper DC brushless motors. They can be positioned with an average precision of 7.5º.
If you want to know more: Speed reducers: main applications and how to improve their operation

CLR’s gear motors: their features:
Have you ever wondered where you could buy a gear motor? Then you should know that at CLR were have a track record of over 20 years designing and manufacturing gear motors.

This experience allows us to offer the best actuator solutions for each company. Our product catalog includes the most common electric gear motor models on the market, which additionally have specific user-defined characteristics based on the use that they will be given.(nema 14 planetary gearbox)

https://jaystep01.weebly.com/blog/gear-motor-basics-functions-and-design-process

http://www.stepper-motor-talk.de.rs/blog/post/how-to-reduce-the-noise-of-gear-stepper-motor-35879