ShopReady Draft 2D · 1:31 · narrated, with captions

A carriage that shuttles between two limit switches, part 3 of 6: Two limit switches and two rules

The Controls section of the Motion window. The carriage is dragged to where the right switch should trip and a limit switch is added there, at 90; a second is added at 0 for the left end, and each is named by typing in its row. Two rules, each a When and a then, turn the motor round when a switch goes on. On Play the carriage shuttles between them, each lamp lighting as it trips.

Before thisA carriage that shuttles between two limit switches, part 2 of 6: A slide, a motor, and why it needs switches NextA carriage that shuttles between two limit switches, part 4 of 6: A counter, an alarm and the log

This is one part of a longer film

Whole project · 8:36

A carriage that shuttles between two limit switches: the whole project

A rack-and-pinion carriage and its control logic, built from a blank drawing in six steps. The drawing side is rectangles, the Gear tool, a rack added to the gear by a right-click, and an assembly. The Motion window gives it a slide and a motor; the Controls section adds two limit switches, a counter, two buttons and a gate, and five rules that read as plain sentences; the control panel runs it. It shows a machine's wiring tried out on the drawing before anything is built: what each switch is for, what each rule does, and the log of what happened.

The rest of this project

Chapter · 1:30

A carriage that shuttles between two limit switches, part 1 of 6: The carriage and its rack

Chapter · 1:15

A carriage that shuttles between two limit switches, part 2 of 6: A slide, a motor, and why it needs switches