Ground clearance

[Adrian Clark]

Originally Posted by SuperNerd256

Thanks for the replies all. I don't have a render, I was just designing in my head. it would be 5" colson wheels mounted by bearing blocks (7/8"), the outer wheels would have a washer under the bearing blocks (1/8"), and then the C-channel (1.25"). It would only be used on a flat surface. The goal was to get the frame as low as possible. The alternative is to mount the wheel+bearing block+washer combination onto the 3/4" tubing we used this year, resulting in the outer wheels having .75" of ground clearance and the inner wheels having .875" of clearance. The wheelbase is about 15" (end wheels are 3.5" away from chassis).

Thanks all for the help!

Thanks for the clarification, I should of realized that you were using that type of bearing block but my mind is on WCD mode right now.

Some things to consider:
-Why use such a large wheel when you have such low ground clearance?
-Why put washers under the bearing blocks? The same effect can be achieved by drilling the bearing/axle hole 1/16" off center and flip the block over on the middle/outside wheels to create the drop.
-Have you considered what gearbox you are using and how the wheels will be driven? Along with obstacle clearance gearing plays the most important role in determining wheel size.

Personally I would suggest having the smallest wheels you can (4" is advisable) while keeping your ground clearance within range. Having smaller wheel means less gear reduction, less weight, less weight in rotating components, and a better looking and simpler robot. It sounds like you're designing your robot around your wheel size and desired frame style. This being an off season project, I wound encourage you to take a step back from your design and think about attributes you want it robot to have and its overall conceptual design before going into specifics like wheel size. Don't design around the frame style you want, design the frame to serve your needs and you'll find yourself with a simpler design. I don't mean to bash on your 3/4" tubing, but in this case in seems like its limiting you from mounting the wheel axles on the same plane as the frame which wound let you run smaller wheel with better ground clearance. Try doing something new and crazy with your frame construction, even if it doesn't work you'll learn loads more than you would from repeating your traditional construction methods.

Just my 2 cents.