Transcription
WheelsBy Sanjay and Arvind SeshanROBOT DESIGN LESSON
LOTS TO CHOOSE FROM LEGO is the largest tire manufacturer in the world! LEGO has wheels of all sizes and also treads43.2 X 2256 X 2868.8 X 3681.6 X 1562.4 X 2056 X 2694.2 X 22 2016 EV3Lessons.com, Last Edit 8/13/20162
TIP: MEASURING THE SIZE OF ATIRE1) Look for the size of the tireon the tire itselfThe first number is thediameter to of the tire in mm.The second is the width ofthe tire in mm.2) Look up the tire on a LEGOcatalogue (e.g.Brickowl.com andBricklink.com), or usingthe LEGO wheels chart bySariel (see page 11) 2016 EV3Lessons.com, Last Edit 8/13/20163
KNOWING YOUR WHEEL SIZE HELPSCONVERT DISTANCE TO ter/ 2016 EV3Lessons.com, Last Edit 8/13/20164
“BEST” WHEELS FOR FIRSTLEGO LEAGUEThere are many options for wheels on your competition robot. There is no“best” wheel.1)Some wheels are better than others, but there is no one wheel that isperfect for every task or every surface your robot will run on.2)Every wheel has a pro and a con3)Do not make decisions on what wheel to use based on someone else’sexperienceCreate a set of tests to see if the wheels can hold the weight of the robot, drivestraight and are fast enough for your tasks (see next page)45560 EV3 Expansion45544EV3 Core31313EV3Commonwheels found inMINDSTORMSsets9797 NXT9695 NXT Resource 2016 EV3Lessons.com, Last Edit 8/13/20165
THINGS TO CONSIDER: SIZE,SPEED, ACCURACY, STABILITY. Large wheels make a robot taller and so might give you both greaterground clearance as well as a higher center of gravity This might be positive as you might be able to to drive overobstacles, but might also make your robot unstableLarge wheels allow your robot to travel further for each rotation,therefore, making your robot faster. Speed can be a positive thing in a timed robotics contest, but yourrobot may not travel as accuratelySmaller wheels are slower but can be more accurate than large wheelsWider wheels allow for more contact with the ground which mightincrease stability, but can also cause more friction.See next page forsample tests 2016 EV3Lessons.com, Last Edit 8/13/20166
SAMPLE WORKSHEETTestsResultsWheel used(List the wheel type and size)Accuracy Test: Movestraight 20-30 inches(Does the robot veer?)Turn Test: Four 90degree turns in a row(Are the turns accurate?)Traction Test: Push anobject(Does the robot skid?)Speed Test: Time to go70 inches, Turn 360degrees(Is your robot fast?)Tire observations(Does the tire stay on the rim or come off easily?)Height and width ofrobot (when usingthese tires)(Does the tire make the robot narrower, wider, taller,or shorter?)You will have to weigh the plusses and minuses of each wheel for your robot. 2016 EV3Lessons.com, Last Edit 8/13/20167
BACK WHEELS: SKIDS, CASTERWHEELS .Back wheels or skids need to allow the robotto turn smoothly. You can create them out ofmany different LEGO elements includingwheels without the tire, LEGO balls, EV3caster wheels, etc. Here too, there are prosand cons. You should test your back wheelsor skids. 2016 EV3Lessons.com, Last Edit 8/13/20168
WHEELS FOR OTHER USESRiding wheels can help your robot drive along walls.FLL Tip: Make sure that they are installed at the correct height foryour table (at home or at competition). You might have either 2X4or 2X3 wood as walls. 2016 EV3Lessons.com, Last Edit 8/13/20169
ROBOTS WITH NO WHEELSYou don’t always need wheels to build a robot that moves!Images from LEGO and LEGO Education 2016 EV3Lessons.com, Last Edit 8/13/201610
USEFUL TOOL: LEGO WHEELSCHARThttp://wheels.sariel.pl/ 2016 EV3Lessons.com, Last Edit 8/13/201611
CREDITS This tutorial was created by Sanjay Seshan and Arvind Seshan More lessons at www.ev3lessons.com LEGO Wheels Chart from http://wheels.sariel.pl/This work is licensed under a Creative Commons AttributionNonCommercial-ShareAlike 4.0 International License. 2016 EV3Lessons.com, Last Edit 8/13/201612
LEGO is the largest tire manufacturer in the world! LEGO has wheels of all sizes and also treads . There are many options for wheels on your competition robot. There is no "best" wheel. 1) Some wheels are better than others, but there is no one wheel that is . 9797 NXT 45560 EV3 Expansion 9695 NXT Resource Common wheels found in .
