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Re: Gravity Vehicle C
Posted: October 24th, 2012, 7:44 am
by Jdogg
bearasauras wrote:How does a 3rd axle help with the paperclip?
technically couldn't you just put a axle in the very front of your car, such that a paperclip can be put in the very front. This might help cars that are short... idk. I'm just trying to think of a reason someone might put a third axle on. Maybe for a braking mechanism.. Like Balsa Man's..
Re: Gravity Vehicle C
Posted: October 24th, 2012, 10:08 am
by Balsa Man
Jdogg wrote:bearasauras wrote:How does a 3rd axle help with the paperclip?
technically couldn't you just put a axle in the very front of your car, such that a paperclip can be put in the very front. This might help cars that are short... idk. I'm just trying to think of a reason someone might put a third axle on. Maybe for a braking mechanism.. Like Balsa Man's..
Yeah, but I wouldn't call what we ran an "axle." To me, an axle is a shaft with two wheels (or a wheel) on it- it carries with it the unavoidable cost of additional friction/energy loss. Think the proper term for our.....additional rotating shaft would be an idler shaft. Ran in it's own bearings, to minimize friction loss, but there was definately an energy loss/absorption price in the gear on axle driving gear on the idler shaft. However, and the reason we went to it, that loss, plus the tiny loss for the 'thread chaser" that tripped the brakes, was measurably less than a threaded axle/wingnut braking system (even with careful clearancing/polishing of the threads). Our two teams ran same chassis/bearings/wheels; team 2 ran wingnut braking; measurably slower. Smaller axle helps the friction loss, but you loose stiffness.
Also, putting a tube/rod "up front', with no wheels on it, would not be an axle, just a tube or rod....
Re: Gravity Vehicle C
Posted: October 25th, 2012, 10:18 am
by XJcwolfyX
"The entire vehicle, including the wheels, must start from an elevated, non-horizontal position on the team's ramp."
Can someone define "non-horizontal position" for me and explain it too? Thanks

Re: Gravity Vehicle C
Posted: October 25th, 2012, 10:27 am
by iwonder
Non-horizontal is pretty much how it sounds...
Re: Gravity Vehicle C
Posted: October 25th, 2012, 10:39 am
by XJcwolfyX
Then can you describe it, or are you just going to make useless comments?
Re: Gravity Vehicle C
Posted: October 25th, 2012, 11:00 am
by Schrodingerscat
XJcwolfyX wrote:Then can you describe it, or are you just going to make useless comments?
I would personally assume that it means the vehicle must start tilted downwards (or technically I suppose upwards as well), and not parallel to the ground.
Re: Gravity Vehicle C
Posted: October 25th, 2012, 11:52 am
by illusionist
XJcwolfyX wrote:"The entire vehicle, including the wheels, must start from an elevated, non-horizontal position on the team's ramp."
Can someone define "non-horizontal position" for me and explain it too? Thanks

Don't think there's much room for doubt on the phrasing of that. Anyway, it means that the vehicle cannot start parallel to the floor. It must be positioned such that the front end of the vehicle is at a lower height than the rear end.
Re: Gravity Vehicle C
Posted: October 25th, 2012, 1:38 pm
by XJcwolfyX
And when it says elevated, that means the wheels can be anywhere above the ground, correct?
Re: Gravity Vehicle C
Posted: October 25th, 2012, 1:46 pm
by InfiniCuber
XJcwolfyX wrote:And when it says elevated, that means the wheels can be anywhere above the ground, correct?
Pretty much as long as it is on the ramp.

Why would you need to have the wheels elevated otherwise?
Re: Gravity Vehicle C
Posted: October 25th, 2012, 2:47 pm
by illusionist
XJcwolfyX wrote:And when it says elevated, that means the wheels can be anywhere above the ground, correct?
Yes. This means that you can't have one set of wheels (the rear axle) on the ramp and the front set of wheels touching the floor.