A Scotch yoke changes a rotating motion into a linear motion. It is an example of a slotted link mechanism. The rotating wheel with an off-centered mounted peg moves the yoke to the left and right. The displacement depends on the size of the slit in the yoke and the position of the peg on the wheel. This 3D printable model is mainly to illustrate the workings. For sure, better designs that include sliding and rotation bearings to minimize play and friction can be thought of. In the model the yoke can be moved by rotating the wheel by hand. Coupling the wheel directly to a motor or using a gear set would provide a controlled linear motion with a changing speed when approaching the maximum extension. See e.g.: https://en.wikipedia.org/wiki/Scotch_yokeThe assembled model includes all parts and could be printed as a whole if the spacings between the moving parts is filled with a removable support. On my simple da Vinci Jr printer I used the plated parts on half the scale (see file) with a 0.2 mm layer height and assembled the parts afterwards. The pictures show the result. The enclosed files 'y1 ... y4' are the stl files of the different parts. Also the FreeCAD macro and model are included. Parameters such as the tolerance between the moving parts can be adjusted easily.