On Mon, 11 Apr 2011 22:01:32 -0700 (PDT)
RS at work wrote:

I am thinking about making a blade adaptor for my lawn mower that has
a sacrificial shear pin so when I am out mowing down the tall weeds
and find that chunk of concrete or stump that someone tossed into the
field it will reduce the stress on the mower engine.
snip

Roger Shoaf

The traditional approach is to mount the blade via a spindle and then
drive it with a belt, pulley setup. The belt will buffer most of the
shock, grief of sudden stops...

You can buy replacement spindles for riding mowers and such. Would take
some thought though to offset the motor and install the spindle.

Personally I just watch for nasty stuff like cement blocks and make
sure I don't hit them I've had excellent success cutting off small
trees/saplings up to around two inch diameter by sneaking up on them
using the discharge chute. Toyed with the idea of cutting a small notch
or slot in the deck for same, but I'm lazy...

--
Leon Fisk
Grand Rapids MI/Zone 5b
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