Eisboch wrote:

"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.
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




My Husqie (the one that was never manufactured) backs up with the blades
running.

Your comments about blade speed and commercial mowers is correct.



--
The modern GOP is little more than an army of moral absolutists led by a
gang of moral nihilists.