Shaper

Vertical shapers are generally fitted with a rotary table to enable curved surfaces to be machined (same idea as in helical planing).

A slotter is fixed in the vertical plane The workpiece mounts on a rigid, box-shaped table in front of the machine.

This flexibility, coupled with the use of specialized cutters and toolholders, enables the operator to cut internal and external gear teeth.

[citation needed] The most common use is to machine straight, flat surfaces, but with ingenuity and some accessories a wide range of work can be done.

But the basic function of a shaper is still sound; tooling for them is minimal and very cheap to reproduce; and they are simple and robust in construction, making their repair and upkeep easily achievable.

They also have considerable retro appeal to many hobbyist machinists, who are happy to obtain a used shaper or, in some cases, even to build a new one from scratch.

Shaper tool slide, clapper box and cutting tool
Shaper with boring bar setup to allow cutting of internal features, such as keyways, or even shapes that might otherwise be cut with wire EDM
Shaper linkage. Note that the drive arm revolves through a smaller angle on the return stroke than for the cutting stroke, resulting in a quicker return stroke and more powerful cutting stroke.