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Unread 15-01-2007, 23:50
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Re: Ramp Angle Survey

Quote:
Originally Posted by DjAlamose View Post
If you have a robot with 4wd tank steering and a 30" wheel base, the maximum ramp angle you can achieve before you bottom out (with 2" ground clearance) is only a 7 degree ramp! (This is looking at when the robot gets to the top of the ramp and is going over that corner).

This is obviously a round about number and i didn't do any special calculations for it, but still it gets the point across.

So, you would need a ground clearance of about 4.3" if the ramp was 16 degrees (the angle I have been looking at for a ramp design). Again this is 30' wheel base and 4wd.

To make getting up a ramp easy, just make your robot 6wd and you should have no problems.

By the way, does anyone know the angle of the ramp 111 (wildstang) used in their 2001 robot?
...
In 2001, our robot had a multi-faceted ramp - it had two different angles. the first angle was 12 deg which transitioned to 5.8 deg which then transitioned to flat. By breaking up the ramp into facets, less than 1 inch of clearance was required to make it over those very gradual humps.
Check out this post to use a spreadsheet I created a while ago to figure out ground clearances:
http://www.chiefdelphi.com/forums/sh...ound+clearance

You will see that with a 30" wheel base you can actually tolerate a 15 deg hump transistion if you have 2" of ground clearance.
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Warning: this reply is just an approximation of what I meant to convey - engineers cannot possibly use just written words to express what they are thinking.