pic: 2 Speed Switching Module

[crazyStone]

Originally Posted by sdcantrell56

There is no "perhaps" in this case. You are limited to a certain amount of traction and thus possible force you can transmit to the ground. With that gearing you will not be able to transmit all that force so then you will just be exceptionally slow. Have a mentor with a physics background or at least some physics knowledge explain how to find the maximum force you can apply based on friction and normal force. It will greatly improve future designs.

Yes I understand there is a limit for the amount of torque that can be transmitted through the wheels. I have had a year of physics and am in AP physics now. The reason I used perhaps, is the fact of weight distribution and the surface area of wheels and material used all play into the how much of that torque can be distributed. Perhaps a configuration can be made that 3.5 ft/sec still transfers torque effectively through the wheels. That is the reason for the prototyping, in addition if we can successfully create the modules with gearing inside of them; it should be much easier task to create modules without switching speeds. This is merely a prototyped design that is being constructed. There is no belief that it will work flawlessly or be a great improvement it’s more of skill building project for preseason. The gear ratios have been made smaller in consideration for what everyone on here has been saying, the low speed has been moved up to nearer 4ft/sec.


I am also confused on which (higher dp) gear you are referring to? There are no gears attached to the traction wheel. That is driven by chain and sprocket from the omni. HOWEVER you are correct that the omni has a higher dp gear (which is what I believe you were referring to), the reason for this is very simple. It is very hard to get 5.5" diameter gears that have the proper bore size and thickness. The reason for such huge gears, Mentors have strongly discouraged the use of chain to connect the switching gear shaft to the omni wheel (their reasoning still escapes me). The design was modified to accommodate this request.