Crap, my newsreader does nothing with that link.
I was dumbstruck. I think it reached 400 MPH when the belt broke.On Fri, 20 Aug 2010 19:43:07 -0700, Beryl <fourl@road.net> wrote:
Beryl wrote:
John Fields wrote:
I've got a sketch I'm working which (hopefully) will make things
clearer, and I'll post it to abse when I finish it, tomorrow sometime.
I hope you're using gears, shafts, chains and sprockets, visible stuff.
I've been working on mine! :^)
Nothing I have the nerve to present yet, but it's real simple - the
wheel is a pulley, there's another pulley on the propeller shaft, and
there's a twisted belt between the two. That's all it takes.
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Perfect!
I used a sprocket on the prop shaft and another one on a right-angle
drive with the input to the drive being the wheel axles, so I wouldn't
have to twist the chain, but I like yours better. Much simpler.
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It looks like as the car goes faster, the wheel goes faster too. And
then the propeller goes faster, so the car just keeps going even faster.
This is scary.
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But thrilling, yes?
How about that moment of discovery when you saw the thing working, in
your mind, for the first time?
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Nice! "3 ROTATION" points the wrong direction though.
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---On Sun, 22 Aug 2010 13:07:46 -0700, Beryl <fourl@road.net> wrote:
John Fields wrote:
On Sat, 21 Aug 2010 13:27:14 -0700, Beryl <fourl@road.net> wrote:
John Fields wrote:
On Fri, 20 Aug 2010 19:43:07 -0700, Beryl <fourl@road.net> wrote:
Beryl wrote:
John Fields wrote:
I've got a sketch I'm working which (hopefully) will make things
clearer, and I'll post it to abse when I finish it, tomorrow sometime.
I hope you're using gears, shafts, chains and sprockets, visible stuff.
I've been working on mine! :^)
Nothing I have the nerve to present yet, but it's real simple - the
wheel is a pulley, there's another pulley on the propeller shaft, and
there's a twisted belt between the two. That's all it takes.
It looks like as the car goes faster, the wheel goes faster too. And
then the propeller goes faster, so the car just keeps going even faster.
This is scary.
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Here's mine:
news:7vov665ft52l6mn2sbog9jtvnbni7u0tbf@4ax.com
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JF
Crap, my newsreader does nothing with that link.
It adds a couple forward slashes after the colon, and a forward slash at
the very end. But no action when I click.
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It's over on alt.binaries.schematics.electronic, subject: "DWFTTW
concept cart."
Nice!
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Thanks!
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"3 ROTATION" points the wrong direction though.
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No. If the wind is blowing from the rear the prop's drag will cause
the cart to be pushed forward, which will cause the wheels to rotate
CCW, (side view) which will cause the prop to rotate CW as shown in
the rear view.
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From a stop, the car backs up into the wind.
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It can't, since it's the drag from the prop that's causing the wind to
push the cart forward, which is causing the prop to rotate "backwards"
until greater than wind speed is achieved
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If the car's already moving downwind when the system is engaged, the
windmilling propeller will brake the wheel's rotation.
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It won't be windmilling until the cart achieves greater than wind
speed.
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If some sort of lock is holding the prop stationary until the system is
engaged, that doesn't work either. The wheel has to counter wind-applied
torque at the prop shaft the instant it's unlocked.
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The only lock on the prop is the wheels, and all that's required for
the cart to move forward is that the drag produced by the prop forces
enough torque to be generated by the wheels to overcome the torque
generated by the rotating prop.
This is the same as the BeanieMoBile that goes upwind, but here you
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And if a lock is needed (if only to clarify the situation), the wheels
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How so?
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