Robotic Arm: Team Roaring Bears
Team Roaring Bears' Robotic Arm
The Roaring Bears constructed a fairly simple arm of total length 44 cm.
They modeled it in SolidWorks using mostly pre-drawn parts, with some additions included, such as the first servo bracket and the pencil holder.
Overall, it was highly successful. It was incredibly smooth-running, despite initial 'junkie' behaviour. However, a lingering problem is the arm's tendency to skew drawings - circles become eggplant-shaped, lines are curved, et cetera. A fix for this is in the works.
The SolidWorks files for the Roaring Bears' Robotic Arm can be found here.
The MATLAB code that controlled the Bears' arm and simulated it can be found here. About the scripts: The sequencer.m script is main file. It can call functions that draw things. The script uses a few global variables, so you can't run any of the functions beside the sequencer, before you first run sequencer.m (hence, defining global variables, including the serial port)
the functions are: draw(path) moves arm from point to point through a 2*n matrix drawLine(x1,x2,y1,y2) calls draw(), interpolating between point 1 and point 2 drawPath(path) calls drawLine() between points on path, a 2*n matrix drawCircle(x0,y0,r,a0) draws a circle with draw() drawPolygon(x0,y0,r,a0,n,skip) draws an n-pointed polygon, skipping 'skip' points. good for making stars, square, etc.