On a modern computerized embroidery machine, the pantograph is the fixture under the embroidery head that attaches to the hoop or the cap driver assembly. This fixture moves in the X and Y axes, moving the hooped material under the stationary needle to produce stitches. The amount and direction of the pantograph's movement from the initial stitch point to the next penetration point are determined by the length and angle of the stitch currently being produced as set by the digitizer in the current design.
The word pantograph, however, originally referred to a device that was used to copy and/or enlarge drawings and writings by attaching a writing implement to a set of levers and a stylus.
Click here to see an example of a pantograph enlarging a shape.
This term makes more sense in our industry if you've seen the use of a pantograph schiffli embroidery machine. In such, an actual stylus and armature are used to individually trace and position each stitch in a design, transferring the placement and movement to the multitude of needles along the span of the fabric. A map or 'cartoon' is drafted to show stitch angles and densities for the operator to follow. The intended art is shown on a 6:1 enlarged map and stitched by the schiffli machine in real time. If you think of our modern pantograph as the second half of this device, with the head unit sending out commands from the digitized design as a replacement for the person at the stylus, the term seems a lot more evident.
The movements of the stylus are transferred to the machine's needles and stitched on the mounted span of fabric in real time.
Click here to watch a video of someone embroidering with a pantograph schiffli.
Source: Erich Campbell