Cadalyst - July 2008 - (Page 16)

techtrends CAD to make sure that [the robot] had the correct height for the two-story telescope.” Team 348 equipped Killer Kowalski with retractable arms that could grip and toss the trackballs. “We modeled the trackball and the overpass,” explained Penn. “We used the various constraints to open and close the gripper, put it through animation to see how it moved, and simulated the drive conditions.” A number of people on Team 217 were sheet metal fans. So they outfitted the ThunderChickens’ robot with a shuttle-and-drive bay made of sheet metal. “Pretty much anything we Figure 2. Team 217’s robot, designed in SolidWorks, used a set of arms made with could, we made out of sheet metal,” inexpensive PVC materials to grab and toss the trackball in the FIRST Robotics competition. said Grant. “Then we sent our design to RackSolutions [a team sponsor], where they manufactured it.” The ThunderChickens’ robot’s arms, which won the be less than 120 lb (without battery) and measure no more General Motors Industrial Design Award (Detroit regional than 28” x 38” x 60”. The use of CAD software allows round), were made of inexpensive white PVC (polyvinyl some teams to experiment with the configuration of their chloride) material (figure 2). “We heated the PVC until assemblies and maximize what they could fit within the we could bend it the way we wanted,” said Frankton. allotted space. When the arms snapped as anticipated, they could be “You can tell which teams designed their robots in software and which ones didn’t,” observed Peter Frankton from easily replaced, and the robot went back into action withThunderChickens. “There were teams like ours, [with robots out missing a beat. that] packed all the minute details into the prescribed parameters, and others with gigantic arms sticking out, Weighing In nowhere near the parameters.” Balance was a common problem with the FIRST contrapBen Martin, design captain of Team 234, or Cyber Blue, tions. For the spectators, part of the fun was watching the recalled, “CAD [Autodesk Inventor] is great for prototyping, mechanical beasts topple over. “When you have a 5’ robot because it lets you see how different parts of [Ritchie X] that transforms into 6.5’, then tries to hurtle a 40” ball are going to fit together.” weighing 10 lb, it can be difficult to keep the robot standWayne Penn, a graduate student at Boston University ing still,” explained ThunderChickens’ Frankton. “So we and a member of Team 348, observed, “CAD [SolidWorks] had to find the center of gravity to make sure the weight is allowed us to double-check and verify before we built the distributed evenly. SolidWorks helped us do that.” machine that the [assembly] did not exceed the physical Norwell Robotics’ Penn said, “We found most of the package constraint.” bugs [in Killer Kowalski] while building it in CAD, so we were able to fix most of the problems.” The use of SolidWorks allowed Team 348 to discover that switching the material for Structural Experiments several parts from aluminum to titanium would have resulted FIRST Overdrive, the main event of the competition, was played on a 54’ x 27’ track, split into a red zone on one side in a lighter assembly, but the option proved unfeasible due and a blue zone on the other by a center fence. The oppos- to cost and additional welding needs. Cyber Blue’s team learned that sometimes the ideal ing teams’ robots scored against each other by crossing the custom part is conceivable in Inventor but cannot be reprodesignated finish lines, carrying the trackballs past those duced easily in a shop. “You can make [a part] as perfect as lines, or knocking the balls off or over the fence. Among you want in CAD,” he observed. “But when you make it, those possible scoring actions, tackling the trackball was for some reason or other — maybe the drill bit is a bit off — rewarded the highest number of points (8). the part ends up looking slightly different, and it won’t fit.” “During the matches, the robot could not expand beyond 80” in any direction. But the trackball it needed to tackle was 40” in diameter,” said Frankton. “So it was a The Chicken and the Egg major design challenge.” When not chasing after its opponents in the ring, Team 217’s Team 234 built an extensible, telescopic arm into creature is actually a sensitive animal. To make this point, Ritchie X (figure 1, p. 14). “It’s a cascade-type telescope the team submitted an entry to the Autodesk Visualization that goes up and down,” explained Martin. “We used Design Competition. 16 www.cadalyst.com cadalyst July 2008 http://www.cadalyst.com

Table of Contents Feed for the Digital Edition of Cadalyst - July 2008

Cadalyst - July 2008 Editor’s Window CAD Central FIRST Robotic Beasts Draw Students to Engineering Power! Speed! Action! — Mighty Mobile Workstations are Packed and Ready for Adventure! Vico Virtual Construction Suite 2008 AMD ATI FireGL V8600 and FireGL V8650 — 1-GB and 2-GB Graphics Cards Gaining Independence and Influence The Current State of MCAD Rewriting the Rules of PDM BIM Goes Residential CAD Cartoon Issue Indexes Pleasures of Customization

Cadalyst - July 2008

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