On Sat, 16 Apr 2011 14:12:54 -0500, DougC
wrote:
I may come to need a pair of helical gears to change a shaft direction
90 degrees, with a reduction of about 4:1 to 5:1 .
I've seen 4.56:1 sets, but they're usually about ten inches in
diameter.
Though they are a bit large, the cheapest sources of these is the gears
from car axles. The stress they will be placed under in my use will be
drastically less than what they'd get moving a car around.
What does the measurement of car R&P sets refer to exactly? I can't find
any place that says.
4.56:1 means that the pinion shaft turns four and one half times for
every revolution of the ring gear. Size is usually O.D., IIRC, but
it's been a long while.
Second I have noticed that many axles are not bevel gears but hypoids. I
would need to know the shaft offset to make a proper housing, since axle
pumpkins are way heavier than I'd want. Is there anywhere online that
gives that info?
Good question.
If there is any other source of perpendicular ring & pinions around
5"-6" diameter I'd like to hear about it.
....ATV's are around the perfect size, but at $200+ a pair, they cost as
much as the much-stronger 7"+ car gears.
ATVs were the source I was going to suggest. Try Burden Surplus at
www.surpluscenter.com . I've seen them there, complete with trannies.
$15-350. Complete ZTR left/right Transaxle Assemblies are about $699.
....Golf carts all seem to use parallel drive methods (roller pinions
instead of bevel gear pinions).
....custom gear places would want $500 to make a pair of hardened gears
that size.
....I have looked at a lot of surplus miter gear boxes, but they're
usually straight-cut gears, or have a reduction ratio that is too high.
Burden might also have right angle gear reduction units for cheaper
prices (made for DC motor use.)
--
Threee days before Tucson, Howard Dean explained that the
tea party movement is "the last gasp of the generation that
has trouble with diversity." Rising to the challenge of
lowering his reputation and the tone of public discourse,
Dean smeared tea partiers as racists: They oppose Obama's
agenda, Obama is African-American, ergo...
Let us hope that Dean is the last gasp of the generation
of liberals whose default position in any argument is to
indict opponents as racists. This McCarthyism of the left
-- devoid of intellectual content, unsupported by data --
is a mental tic, not an idea but a tactic for avoiding
engagement with ideas. It expresses limitless contempt for
the American people, who have reciprocated by reducing
liberalism to its current characteristics of electoral
weakness and bad sociology. --George Will 14 JAN 2011
Article titled "Tragedies often spark plenty of analysis"