Proping Question

On Sat, 19 May 2007 01:13:55 -0400, Jose
wrote:

The crank has a ratchet and will
free wheel if the engine pops backwards.

How would that work? The engine going backwards against the crank
imparts the same (direction) force as the crank going forwards against a
recalcitrant engine. That would freewheel too, defeating the purpose.

A simpler version of the ratchet: The way it worked on my '41
McCormick-Deering tractor (sorry Cubdriver, mine had rubber tires),
the crank and the socket were machined with matching flats and
matching ramps. When you were applying torque to start the engine,
the flats were in contact, but when the engine started, the slanty
bits slid past each other and expelled the crank.

But if that sucker tried to run backward, the flats would continue to
engage and the crank handle would do something nasty. Not that it ever
tried that on me.

Jose's right.

Don

If the crank shaft tried to drive the crank handle (as during a kick-back), it would spit the crank handle forward and disengage it.

It is like the screw heads you see on some bathroom stalls where the slot in the screw head has ramps behind it on opposite sides such that you can tighten with a normal screw driver, but you can't easily remove it with a normal screw driver.

That doesn't make sense. Using the screw head, if the screw lurched
-forward- (in the direction you are trying to turn it) that would push
the screwdriver out. But if the screw turned backwards, that would push
against the screwdriver and kick =you= back.

Maybe there's an intermediate system?

Jose
--
There are two kinds of people in the world. Those that just want to
know what button to push, and those that want to know what happens when
they push the button.
for Email, make the obvious change in the address.

On 2007-05-18 13:57:02 -0700, "Capt. Geoffrey Thorpe" The Sea Hawk at
wow way d0t com said:


So, we are arguing over the definition of the word "run"?

I s'pose. Well, it has been an interesting thread. I suppose it will
run on for awhile now, until someone calls someone else a Nazi. :-)


Now, if you brought your car in to where I work because it would just fire a
couple cylinders and quit and I tried to tell you that it was "running"
wouild you buy that? :-)

But, yea, one cylinders worth of "running" would be all it would take to
split one's skull.


--
Waddling Eagle
World Famous Flight Instructor

On Sat, 19 May 2007 14:00:18 -0700, C J Campbell
wrote:

I s'pose. Well, it has been an interesting thread. I suppose it will
run on for awhile now, until someone calls someone else a Nazi. :-)

Call yourself lucky. Over on rec.music.opera, they insult one
another's body parts.

Blue skies! -- Dan Ford