Gearing is one of the methods of converting the rotary motion of the stepper motor shaft into a translational motion of the table, gantry or spindle. It is used for large format machines that do not require high positioning accuracy. Examples include: woodworking, engraving on slabs (0.2-0.3 mm accuracy is sufficient to apply the design to the surface of monumental slabs), cutting thin metal sheets into individual blanks for subsequent processing cutting machines in shops without plasma or gas.

The gear elements of the simple mechanism are made of high-carbon structural steel, and heat treatment is an improvement. However, the rack and pinion used in the kinematics of CNC machine tools are made from alloy tool steel. The surfaces are glued and therefore stronger and more wear-resistant than mass-produced products.

Advantages and disadvantages
This type of transmission is imprecise and therefore not used in high precision equipment. Disadvantages include increased noise levels, but helical gears have lower noise levels than spur gears.
Rack and pinions offer many advantages that dictate their widespread use in low-cost portal machines, despite the relatively low precision of movement:
Easy to install – the rails are screwed directly to the table or door frame without the need for additional support. The mounting holes are locally made, allowing freedom to choose the appropriate mounting method;
Maintainability is higher than with ball screws – there is no need to select nuts produced by the screw manufacturer. Individual elements (rack and pinion) of gears from different companies are interchangeable;
Higher travel speeds when idling than when using ball screws;
lower sensitivity to dust and debris (but desire to protect the drive from large amounts of production waste).

Another advantage is the ease of selection. To select a gear, it is sufficient to know the pitch circle diameter of the circle (these are the last two digits in the gear marking) and the module. For load gears, select a rack and pinion set with a module of at least 1.5, and for no-load and high-speed gears, select a gear with a module of 1 or less.