@Plz Full screen, Use Headphone! @ Maxon today video http://www.Maxon.net Role: Art Direction, Design, Animation, Modelling, Compositing, Sound Design Co-worker : Jaehong Park(Yonsei Univ) Date: 2010.11.01~12.14 Format: 1280*720 HD Sound: Basique Little People Tools: Cinema4d r12, aftereffects, premiere Render time : 3 Days Copyright 2010 atenis@nate.com http://blog.naver.com/~atenis http://atenis.cafe24.com This time, my friend and I had a chance to do a project about mechanism design. In this video, we will show you especially about four-bar linkage and gear trains. For instance, riding a bicycle has two mechanisms, one for four bar linkage, and the other for gear trains. And the watch, for example, is consist of numerous gears. Almost everyone takes the watch in daily life, but just a few knows about the principle how it works. Synthesis of mechanism is not shown in this video, only analysis is presented. When we analyze the mechanisms, we used "Graphical analysis method" and "Analytical analysis method". Calculating with vector loop equation, and reviewing with graphical method. Showing how the gears in the watch rotates was really difficult for us. We knew the theoretical angular velocity, but C4D was not accurate to realize them. Finally, we tried FPS division method and it worked, On analyzing four-bar linkage with bicycle, we used tracking function with AE. We hope all of you can be more familiar with mechanism design through this movie. Merry christmas and Happy new year. Intro Preview http://vimeo.com/17593568 S1 Preview http://vimeo.com/17593507 Xpresso Preview http://vimeo.com/17593083 Additional engineering statement Case : the bicycle We first thought that analyzing the mechanism of riding a bicycle would be really easy because the length of every linkage was determined so we could parameterize every four angle, angular velocity and angular acceleration with one specific angle. But it was totally a mistake. Finally we divided 2Π rad in to 10 sections, which means every 36°, and found values related to the angle and interpolated them to make continuous numbers. When climbing up the ascent, we assumed the length between the saddle and the crank axis varies. We set up the equation (which is used in this movie) of the length as "85+5sin(angular velocity of the crank*Π*t)cm" so that the length varies from 80cm to 90cm. It was quite reasonable to set up the equation as above except for a few errors. For instance, following that equation, the length becomes the smallest when the pedal is on the lowest position and largest when on the top, but that assumption makes the motion of the bones seem forced or unnatural. This equation is to be complemented soon enough. We calculated 7 sorts of variables; angular velocity, angular acceleration, velocity, tangential acceleration, normal acceleration, relative velocity, relative acceleration; but inserting all of those values made the pictures disoriented thus we got rid of every value except for angular velocity. Case : the watch In designing the gears, we did not consider the pitch radius or pressure angle so it does not fit to the engineering models. But the angular velocity ratio of each gear related to the number of teeth ratio was designed precisely. In engineering concept, the gear must have at leat 12 teeth so the second gear, called Escapement gear, has 12 teeth in the video which has actually only 6 teeth. And we want you to watch very carefully how the minute hand gear affects the hour hand gear with converting gear 2, because even concepts of those concentric hand gears movement was not easily understood, we costed about 3 days to realize it. In this film, we do not present the torque of the gears in the bike or watch. With a piece of paper and a pen, most of you can caluculate it with no longer than 10 minutes.