Escapement MacDowall (305)

grabcad

This is a very simple escapement mechanism - ready to be used as the heart of a clock. Mainly, there are only two mobile parts: a crank and a pendulum. The parts and assembly are modeled with Autodesk Inventor 2014; Dynamic Simulation and Inventor Studio were applied to obtain the results. The mechanism is supposed to be driven by a weight hanging on a thread wrapped on a reel, but the weight and thread are not present, their action being replaced by a constant momentum of 1.5 N·mm applied to the crank through the reel placed behind the pedestal, in the clockwise direction. The movement is started exclusively by the crank from the first moment, as you can see by watching the Video. After a fight with the inertia, the crank starts the movement of the pendulum, which gains an increasing amplitude. The amplitude becomes stationary after a while, and this will be the stable behaviour in a normal functioning of the mechanism. I have to mention that no friction was involved. The contact between the cylindrical part of the crank with the interior window of the pendulum has a null restitution, as well. You can experiment for yourself all the dynamic sensation. Open with Inventor Professional 2014 (or 2015, ...) the „Escapement MacDowall (305).iam” file from the Download directory, then enter Environments/Dynamic Simulation. The Simulation Player dialog box will be present on screen. Click on Play button and watch the movement. After it reach the end, click on the leftmost button in the dialog box (Construction mode), and change any settings you want. For instance, double click on the „Torque” object and change the value of 1.5 N.mm with another value, slightly near this one. Click again on Play button and watch the changed movement. The idea comes from here: http://507movements.com/mm_305.html By comparing with the included „Start picture.jpg”, you will notice that the crank must be placed centered with the pendulum. Some practical applications are: https://youtu.be/GuqLck6ag98 https://youtu.be/osUvoeMAMrA When you see how rudimentar are the last two constructions, you cannot stop to think: „I wonder if I can simulate these so simple things with my beloved CAD software...”