finish mower/ leaf blaster?

[BrettW]

Hi,
Can it hurt, or is it a bad idea, to run my 5' Midwest finish mower at very high speed in order to grind up leaves? Don't want to hurt it, but would like it to grind up leaves that I don't want to rake. thanks, Brett w

 

[markie61]

It's what I do. The worst you will do is burn up a belt. I bought a new 7' rear discharge mower this spring, but it doesnt grind up the leave too well. I got my old 6' side discharge mower out of the woods and it chops them much better, but the unibelt gets strained. I listen for the blades slowing and adjust my groundspeed accordingly. The side discharge also allows me to direct the chopped up leaves out of the way.

Mark

 

[djradz]

I'm not sure what you mean by "at very high speed" but I would follow the manuals for you tractor and mower deck. For instance, if you happen to have a tractor with both a 540 rpm and 1100 rpm PTO output, I WOULD NOT run the deck at the 1100 rpms unless it is rated for such. I don't think you'd have a problem if you ran your tractor at the 540 rpms, however with the engine rpms slightly higher than whatever produces 540. Such as, if 540 equates to 2500 engine rpms, I don't think you'd have a problem running the engine at something like 2600 rpms, but anything higher than a little over rating and I think you are jeapordizing the life of the deck.

 

[Pks]

There are two big parameters that are affected by speed: first is the blade tip speed, second is the support bearings for the blades and gearbox.

The blade tip speed is the most sensitive. That's due to rotational inertia creating very high pressures in the tips of the blade. Blades have been known to explode because of high rpms.

The bearings would probably handle additional rpms because they are sized by force load and cycles. It's been my experience that bearings, when well lubbed and cool, can handle far more than one would expect.

FWIW, I use my 6 ft, 3 spindle finish mower to chop up my 2 acres of leaves. It does a great job! The blades must be SHARP and the leaves fairly dry. I don't raise or lower the deck. I just cut the leaves as I cut the grass.