[AT] How can they farm like that

[Indiana Robinson]

>
>
> ---- charlie hill <charliehill at embarqmail.com> wrote:
> > I remember reading one Progressive Farmer article about tire slippage
> where
> > it explained
> > that a tire could not roll without slipping (I guess unless it had an
> > infinitely small contact patch).
> > It continued to discuss the optimum % of slippage for applying HP to the
> > ground.  If I remember
> > right it was between 12 and 15%.  It occurs to me that that percentage
> range
> > turns up a lot in
> > agriculture and construction.  Everything from wheel slippage to moisture
> > content in grain
> > and also in the wood in a building.
> >
> > Charlie
> >
>


I think that I once read that just pulling an empty wagon at 10 MPH was
about 5% slippage.
I never figured percentages but when I was doing field work I watched the
tire to ground contact closely. When plowing on an average I didn't want to
see an individual lug slip more than about 3/4". Once watched a neighbor
about 1952 plowing with a 9N with tires worn down to less than 1/4" and I
swear that he was moving forward about 3 feet per tire revolution if that
much.
:-)
I also always tried to balance loading so that I could pull it at least 5
MPH and drop RPM down to around 1200 then recover very quickly to full
loaded RPM. If possible I liked running about 5.5 MPH but not all tractors
had a gear right for that. My 4020 did. I usually pulled my 16' IHC winged
disk at 6 MPH. It pulled remarkably easy even running deep. I could  have
pulled it faster but 6 MPH was one of those sweet spots as far as the job
it did. I never like lugging a tractor other than for tough spots or jobs
with an erratic pull.
Funny... Spell check thought that erratic should have been "erotic".
:-)


-- 
>

Francis Robinson
aka "farmer"
Central Indiana USA
robinson46176 at gmail.com