flail mower upgrade heavier knives

jonsstihl · Aug 1, 2016

I have a mott 72 HD using the grass knives mounted on D-rings and I was wondering if anyone had any experience switching over to heavier grass knives. The .087" thick ones cut grass fine but as soon as I hit a little stick I hear a bunch of clicking and the stick seems to not get damaged very much.

I am mowing at the highest setting so maybe that has something to do with it but If I'm replacing knives anyways, I might as well try to upgrade and get a little more brush cutting ability. I'm not looking to mow 3" thick stuff but It would be nice to do more damage to a 1/2" sapling that is in the way.

leonz · Aug 1, 2016

NOPE, its not going to happen without some knife damage provided you invest in
heat treated knives. Mow more often, it would be the best way to handle this
providing you back over the thicker brush with the flail mower running and then drive
forward to shred it a second time. Even then you may have knives that are damaged
or broken from impact. You need to knock all that thicker brush down with a saw,
even a chain saw pole pruner would work quickly on those 1/2" saplings.

After that, mowing at 2 inches in cutting height is best for all situations.

4570Man · Aug 1, 2016

A flail mower can't cut 1/2" saplings? My lawn mower easily does that.

Fallon · Aug 2, 2016

My ancient Ford 917 with side slicers will cut some wood, but not fast or well. It's not even in the same league as my rotary cutter. It stripped the branches off the live Christmas tree we planted & didn't make it. Didn't do much on the trunk. I occasionally will run over a very small tree or branches intentionally & it will demolish small stuff, but not that well & is slow & noisy about it.

jonsstihl · Aug 2, 2016

I thought having thicker knives would increase the impact force enough to do more damage to small branches.

So far this mower isn't doing much mulching but I suspect it is because I am cutting too high. You mention two inches high but where on the knife do you start that measurement because right now with my roller set to the lowest position (highest cutting height) the end of the knives are just under 3" from the floor.

leonz · Aug 2, 2016

The knife tip is the actual mowing height in the scheme of things. Put the mower on wooden blocks and raise the rear roller one position at time to lower the cutting height.