Download
slide1 n.
Skip this Video
Loading SlideShow in 5 Seconds..
CAD PowerPoint Presentation

CAD

152 Vues Download Presentation
Télécharger la présentation

CAD

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. CAD Hans Johnson Build/Design Captain FRC 3018 Nordic Storm 2013 Lake Superior Excellence in Engineering Award 2013 10,000 Lakes Engineering Inspiration Award 2013 Championship Xerox Creativity Award

  2. Why do we use CAD? • Model robot • Concepts • Testing • Iterations • Modifications between tournaments • Make drawings • Sponsor machining

  3. Organization • Nordic Storm’s 2013 Robot had over 100 parts and sub-assemblies • Each subsystem was assigned a prefix • A = Actuation • C = Climber • D = Drivetrain • DMP = Dumper • P = Positive Engagement • R = Full robot assembly • Followed by name of part, e.g. C_ClimberPivotPlateLeft • Each subsystem had an assembly, combined into full robot assembly

  4. Dropbox • Nordic Storm uses dropbox to sync and back up our CAD files • Offers 30 day version control • Free • 2GB of space, invite other members to get more space • Allows everyone to work from one set of files, rather than moving them around on a flash drive

  5. Our Process • Drivetrain CADed within the first couple days • Manipulator/superstructure designs in parallel with prototyping of mechanisms • Once full robot model is largely complete, parts that will be manufactured by sponsors are sent off • For parts made in house, drawings are made and reviewed by a mentor before being printed and given to student machinist. • As parts are assembled, tested, and the design is modified, the CAD model is updated nightly

  6. Simulation • FEA • Size • Motion

  7. FEA • Finite Element Analysis • Used to determine stresses on parts • Will a part hold up under expected load? • Change material (AL vs Steel) • Increase thickness • Shows points of high stress

  8. Size • Does the robot fit within size limitations • Frame perimeter easy to measure • Our articulating robot fitting within cylinder

  9. Motion • Simulate motion of mechanisms • Do parts collide? • Cam system on this year’s robot when folded • Are there collisions?

  10. Gotchas/Tips and Tricks • Design some tolerance into your parts • Holes on laser cutting/waterjet should be cut small and drilled/reamed to size • Nesting parts – blocks into tubing • Clearances between moving mechanisms • Things get bent, make sure it won’t break something else if it does • Things won’t be perfect, make sure your design can handle that • Electronics boards • Make sure they aren’t an afterthought and there is enough space for everything • Make sure they are accessible • Battery • It’s big and heavy, use it to your advantage and include it in your design • Inventor has a CoG calculator. Use it! • Many COTS parts have CAD models available that can be imported • AM • McMaster • 3D Content Central

  11. Frame Generator • Inventor has a built-in frame generator • Provide a skeleton, and Inventor will create the proper lengths of tubing, pipe, extrusion, bar stock, etc

  12. Drawings • Drawings are made for all parts machined in house or sent to sponsors with material • Part files sent for laser and CNC • After part is created and design is reviewed by multiple students and mentors, a drawing is created • Drawing is then checked to ensure it is complete before printing • Each drawing has a revision number in the title block to avoid confusion between multiple versions of the part – updated every time the drawing is printed