"Johnson" wrote in message
...
Eisboch wrote:

Scag dealer and also confirmed by our landscaper who obviously only buys
commercial equipment. He's the one who recommended that I buy a
commercial mower for the purpose I needed (mowing large horse paddocks).

The residential tip speed limit is a federal regulation. I forget what
it is exactly, but something like 1750 feet/min rings a bell.

I couldn't find anything specifically regulating residential mower blade
tip speed, but did find that there is a federal regulation concerning all
mowers at 19000 fpm top blade tip speed. Most commercial mowers appear to
advertise at between 18000 and 19000.

Shamelessly cut and pasted:
---------------
American National Standards Institute (ANSI)
ANSI standard B71.1, Walk-Behind Mowers and Ride-On Machines With Mowers -
Safety Specifications, is the primary safety standard for homeowner riding
mowers and small tractors. This standard requires the use of an operator
presence control, a device that will stop the mower blades if the operator
leaves the seat without disengaging the blade drive (PTO). This prevents
an operator from being down on the ground around a mower while it is
running.

One of the most important features of this standard is a requirement that
the blades must stop turning within 5 seconds when the PTO is disengaged
or the operator leaves the seat. This requires an automatic brake on the
blade drive. ANSI also requires that mowers be tested to strict
performance standards for thrown objects.

A seatback height of at least 4½ inches is required to keep operators from
falling backward. There are requirements on dynamic turn and sudden
traction performance to improve machine stability. There are requirements
for braking performance. There are also requirements on guarding and
safety labeling. The blade tip speed is limited to 19,000 feet per minute.
----------------

That would seem to indicate that there is no specific lesser top blade tip
speed for a residential mower.

It still could be true, I suppose, that the manufacturers of residential
mowers spin the blades slower, but that may not be necessarily true in all
residential machines.

Johnson.



When were those regulations written? My Scag is about 8 years old now, I
think. I know one thing. The blades don't have a brake on them. I have a
newer push mower that operates as described in your posted regulations, but
not the Scag.

Also, I believe that residential rider mowers have had a requirement to
automatically disengage the drive to the blades when the rider mower is put
into reverse to back up. The last two lawn tractors I had did this and one
was an old, 1990 vintage John Deere.

The commercial rated Scag doesn't do this either. Blades stay engaged both
forward and backward.

Leads me to believe the regs you cited are for residential rated equipment.

Eisboch