3D Printers

3D printers are a very popular product now.  They vary immensely in cost and complexity, and in accuracy and size.  At one extreme, modestly priced kits are available on-line, and at the other,  large and costly machines are capable of highly accurate components.  Where once 3D printers were producing parts known as ‘rapid prototypes’, they have matured now to the point that actual components are made in sizable volumes for such as expensive production cars.  They offer the potential of realising parts and ideas in a matter of a few hours and making components with characteristics that are very hard to make any other way.  Their traditional disadvantage was limited quality and the best quality available now is greatly improved.  

3D printers are all about positioning.  Placing the print head in the correct place to build a component.  Stepper motors are a product which moves in steps and are ideal for 3D printer applications. Having computer-controlled stepping means you can get very precise positioning and speed control.

Typically, there are four stepper motors per machine.  The stepper motors are frequently open loop steppers, called hybrid steppers.

A hybrid stepper motor combines features of two older technologies: PM Permanent Magnet steppers and VR variable reluctance steppers.  Hybrid steppers have now effectively superceded the earlier earlier technologies and become a default.  In a 3D printer application, typically a stepper motor will be oversized by about 50% to ensure that positioning is reliable. 

Stepper motors position the head of the 3D printing machine in three dimensions.  The x and Y dimensions are sometimes driven by a belt.  The Z direction will carry more weight as it carries the tool head, and typically uses a lead screw.  The leadscrew drives a thermoplastic nut attached to the z axis.  The fourth stepper will drive the filament feed. 

The stepper motors in 3D printers come in NEMA sizes.  NEMA is National Electric Motors Association, which is in the US.  NEMA motors have a square face with a mounting hole at each corner.  As an example, a NEMA 17 has a square face with 1.7” between each mounting hole.

Closed loop steppers are available with encoders to confirm positioning.  This allows the possibility of errors being reported prior to the component being finished.

Motion Control Products supply a wide range of stepper motors and also a wide range of stepper drives.  Our drives will work with a wide range of protocols and some will mount onto the stepper motors.  We’ve supported and been involved in a wide range of projects for 3D printers and are ready to help and discuss further projects with our customers.