Thread: Bumper height v. height of "the bump"
View Single Post
  #6   Spotlight this post!  
Unread 10-01-2010, 20:58
Nathan Streeter's Avatar
Nathan Streeter Nathan Streeter is offline
FIRST Fan(atic)
FRC #1519 (Mechanical MAYHEM)
Team Role: Mentor
  
Join Date: Feb 2008
Rookie Year: 2006
Location: Merrimack, NH
Posts: 676
Nathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond repute
Re: Bumper height v. height of "the bump"
You were right the first time - the top of the *bump* is 12" of the ground, with a 45 degree slope. The *platform* - the deck of the tower - is 20" off the ground.

You are right that most of the bumper will be higher than the bump. I used a 2D CAD sketch, with a bump and robot with bumpers, to analyze this issue - if you can also, that'd be great!

I discovered that if you build the bumpers at 10" (the lowest extreme) that you can use a tire size smaller than 16" to climb the bump. Surprisingly, tires larger than 16" will hit the bump with their bumpers first, rather than the tire. So, as long as you a tire smaller than 16", about as far forward as you can possibly design them, you should be perfectly fine getting up the incline of the ramp.

I do recommend doing this analysis yourself, if possible, because a robot with 4" tires - smaller than I think anyone would use - actually would need to have 10" of ground clearance to avoid "bottoming-out" on the crest of the bump.

If you have any questions, feel free to ask. Good luck to you and your team!
Reply With Quote