(ET) Snowblower vs. Snowblower

["Steven Naugler" <snaugler earthlink net>]

    The following is in response to questions about snow blower questions.
    I have seen new single stage snow blowers in Sears that apparently are
made by the same company that made the GE versions 20+ years ago and appear
to be nearly identical to our GE supplied ones.  Therefore I can't believe
that the more recent GE supplied blowers are any different than the older
ones.  I think any performance differences would most likely be due to
differences in the snow; dry vs. damp.
    The following is an educated guess as to why single stage blowers are
marginal in damp snow.  (Even my GE worked well when the snow was light and
fluffy, unusal for us in Delaware.)  First some snow blower anatomy.
    A single stage snow blower has a two opposite metal spirals of opposite
winding welded to a drum.  They join in the center where they form a scoop
of sorts, that is in line with the discharge chute.  This drum is spun at
rapid speed; so rapid that any snow that makes its way to the center is
thrown out the chute, hopefully at high speed.
    A two stage snow blower has a low speed auger that looks quite 
different
than the drum arrangement in the single stage design.  This auger is
fastened to a shaft that spins much more slowly.  This auger moves snow to
the center where the second stage, a very high speed paddle, throws the 
snow
vigorously.
    Here's the educated guess part:
    In the single stage all of the snow must be moved by the high speed
drum.  When the snow is wet, it packs easily.  The wet snow as it moves
along the spirals on the drum is pushed against the snow blower casing
creating a lot of friction.  In order to keep power manageable knowing wet
snow was a possibility, rpm was limited by the original designers for both
gasoline and electric versions of the single stage blowers.  When the snow
is dry, this lower energy is enough for good blower performance because
friction effects are lower.  Given a higher power and strength to handle 
it,
a single stage at higher speeds would probably work better than present
single stage designs.
    In a two stage the first stage works much more slowly and tends to pack
wet snow very little as it drives the snow to the center located second
stage.  The second high speed stage will pack the snow, but because the
volume that can be packed up is small, you can afford to put more power 
into
that stage and overcome any packing effects.
    My first conclusion is that damp snow will always take more power to
blow than dry snow.  It is just that a two stage snow blower takes a much
smaller power increase to handle damp snow than a single stage.  This power
increase for the two stage is so small that in most cases the extra power 
is
built in.  In a single stage blower it would be prohibitive to build in 
that
much extra power, especially for us electric tractor folks where energy is
at a premium.
    My second conclusion is that if you live where the snow is usually dry
and fluffy, keep your single stage blowers.  If you live where the snow is
damp, sell them to our friends in the midwest.
    Lastly, Dave Roden asks if we could convert our GE single stage to two
stage.  Dave, yes, we probably could, but with difficulty.  We would also
lose some performance.  The auger in a two stage has a design to break up
ice and other lumps at low speed.  I don't think the drum with spirals of
the single stage would break these clumps up at low speed.  You could
probably graft a 10 hp class second stage to the center of the housing and
drive that at high speed.  A creative use of a belt drive and gearbox could
probably drive the drum slowly.  My guess is that the usually supplied DC
motor from the existing single stage when used with a more efficient two
stage would have enough power.
    Does anyone know who made a two stage tractor mounted snow blower.  I
know that Honda does, but they will be very costly even used.  John Deere
does only in their larger designs; their blowers sized right for a GE are
also single stage.  I have seen one other two stage, but cannot remember 
the
manufacturer.

Hoping for lots of controversy,
Steve Naugler