Flail Mower Let's talk flail mowers

[leonz]

I am trying to help you here, just like I have helped everyone else that wants to invest in a flail mower or has operating problems with them.

They are more worried about scalping when they suggest this method of operation that is all that is about. as it keeps the knife stations that are following the leading pairs of knives elevated and as a result they lose the pressure gradient needed to slice the grass and brush and also reduse the amount of recutting the knife pairs can do by leaving a higher height of cut.

The image of the Peruzzo pick up mower that I have attached to this response shows a pair of caster wheels in the front of the flail pick up mower to prevent scalping and knife damage. If the manufacturers of these things offered front caster wheels as standard equipment in their flail mower builds they would sell many more flail mowers as they would mow better and as a result create better turf as the caster wheels act as an additional aid in maintaining the mowers cutting height along with the rear roller.

The Wessex towed motorized flail mower in the second image can be towed by an ATV/quad bike or an SUV to mow and it has front and rear gauge wheels and does not use a rear roller as it is designed to mow in heavy deep brush.

The Vrisimo flail mowers made in California can be purchased with front and rear casters as an option in just one instance.

The older mott flail mowers had rear casters as an option to aid in protecting the flail mower from suddenly dropping into a depression by nose diving into it if the mower was left in the float position and then causing scalping and knife damage.

Liek I said I am only trying to help you here.

 

[AGTtactical]

I would have to respectfully disagree with this. The scoops (and Ford's airplane wings) have much better design to create a suction to lift. Their design is much like a furnace blower (in reverse actually). The scoops are angled so that when the blade is at bottom dead center there is an angle along the blade facing upwards creating high pressure on the top side and low pressure on the bottom side creating a lift. The side slicers when at bottom dead center are parallel with the ground creating no lift. There is "wind" created by them simple by displacement of air, but no "lift". I noticed that with my Ford 917 that when I switch from airplane wings to side slicers my tire tracks are not being cut as well as before. This would reaffirm the lift the wings and scoops create vs side slicers.

The hammers may or may not have lift depending on their design and the way they spin on the rotor.

Every flail is created differently. To say otherwise is like saying that all tractors are created the same and operate the same regardless of who manufactures it. My Ford 917 is designed to take different knives for different jobs including switching between rough and finish mowing blades. Some mowers you need to change the rotor to do so, and some don't even offer the option to go to finish mowing. Some mowers rotate the same as the tires, some opposite. It's all in how the manufacturer designed it and I would follow what the manufacturer says on how to set it up and use it. They designed it to operate a specific way and to do otherwise is counter productive.

Now that is a good post! I agree entirely.

 

[leonz]

I would have to respectfully disagree with this. The scoops (and Ford's airplane wings) have much better design to create a suction to lift. Their design is much like a furnace blower (in reverse actually). The scoops are angled so that when the blade is at bottom dead center there is an angle along the blade facing upwards creating high pressure on the top side and low pressure on the bottom side creating a lift. The side slicers when at bottom dead center are parallel with the ground creating no lift. There is "wind" created by them simple by displacement of air, but no "lift". I noticed that with my Ford 917 that when I switch from airplane wings to side slicers my tire tracks are not being cut as well as before. This would reaffirm the lift the wings and scoops create vs side slicers.

The hammers may or may not have lift depending on their design and the way they spin on the rotor.

Every flail is created differently. To say otherwise is like saying that all tractors are created the same and operate the same regardless of who manufactures it. My Ford 917 is designed to take different knives for different jobs including switching between rough and finish mowing blades. Some mowers you need to change the rotor to do so, and some don't even offer the option to go to finish mowing. Some mowers rotate the same as the tires, some opposite. It's all in how the manufacturer designed it and I would follow what the manufacturer says on how to set it up and use it. They designed it to operate a specific way and to do otherwise is counter productive.

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One must also have sharp cutting edges to mow well so that must be a priority.

"The current design of many flail mower rotors that have narrow knife mounting stations that do not allow the knife sets to become aerodynamic and allow the knives to become wings".

When a D ring or tool less knife mounting station is used the side slicer knives are typically mounted with its loop mounting hole where they can quickly become airborne and the knife edges become level to permit them to clip the grass and brush at the same height where the narrow knife mounting stations will create a sawtooth pattern on the cut of grass blades on good sod if it is mowed closely.

The scoop knives cannot recut material a second time unless it is brittle and has little weight.

This is why flail crop shredders made by Mathews and others use a cast and machined wide scoop knife to clear the crop residue in peanut trash, potato vines, cotton vines, sugar cane stubble, sugar beet toppers, and pineapple root stubble along with mowing down alfalfa and clover crop growth at the end of the growing season to help prevent damage to the grass crops from leaving the growth over winter which makes the grass crop more prone to freeze damage through the growing grass left after the second or third cutting making it more suseptable to winter kill which will affect the following seasons hay crops.

After 44 years of using and maintaining and repairing these machines I am only trying to help the new user as the flail mower is a better mower for all conditions.

 

[bruceha2000]

...
The scoop knives and hammer knives do not have the aerodynamic design to lift and recut clippings and brush.
...

Staying out of the argument here!!!

But since you specifically mentioned scoop and hammer knives in that statement: Does it also apply to slicing knives? WoodMaxx Y blades:


I see that the instructions to run the mower 10-15ｰ lower in the back are general not specific to what blades are being used. Also in one section it says this is to prevent scalping. The instructions are for all the models they sell.

It does sound like an individual might want to start with the 10-15ｰ and adjust as necessary for better cut, especially if they have very uneven ground.

 

[bkrgi]

Here be my take on aerodynamics..... you want a perfect cut buy a finish mower. Want a rough cut with a great finish, given what your mowing ...get the flail. Want a rough cut with poor finish....buy the rotary brush hogs.
If you want to fiddle then follow Leon's advice otherwise set it reasonably level and just use it. I know the Woodmaxx moves a lot of air out the back but in no way am I looking for perfection of a finish mower. It is really difficult for any mower to lift long material if it is matted to the ground for the blades/knives to catch it.
To better the finish with any mower, double cut it.
If you have time then fiddle and check settings with all mowers to get things set perfectly as each does require such fiddle for max performance.

 

[dieselscout80]

I noticed that with my Ford 917 that when I switch from airplane wings to side slicers my tire tracks are not being cut as well as before.

TheFarmerInAdell, did you notice a difference in the horsepower usage of your 917 when you switched from the scoop knives to the side slicers?

 

[otus_branch]

No, I am not arguing with you.

They have not been making flail mowers for very long. They simply entered the flail mower market to increase their market share of the sub compact and compact utility tractor implement market.

Like almost every other manufacturer currently manufacturing flail mowers in Asia, The United States and Europe they are using a small tubular flail mower rotor without adding air paddles to increase the efficiency of the flail mower knives and increase the ability of the flail mower rotor and knives to become more aerodynamic and create more lift with the added mass of the air paddles and the mass of air which has weight and creates a pressure gradient when entering the flail mower shroud.

(snip)

I am stating again that the flail mower or any flail mower/orchard and vineyard shredder/crop shredder for that matter needs to be level to create the resistance to needed to create the pressure gradient(suction) to pull the clipped material over the flail mower rotor.

Flail shredders used for crop shredding are always left level whether they are shredding flat land crop residue or ridge tillage crops. Crop shredding is much more difficult to do as it takes more gearbox horsepower and engine horsepower to do.

Hi leonz,

I have only used my Woodmaxx FM78H equipped with knives for a few (~8) hours so far, but if anything, I have tilted it even more than 15 degrees. And the suction and re-cutting action is excellent. No concerns whatsoever on this front, whether conditions were wet or dry.

 

[TheFarmerInAdell]

TheFarmerInAdell, did you notice a difference in the horsepower usage of your 917 when you switched from the scoop knives to the side slicers?

As I said before, it wasn't a fair comparison. New knives and a new tractor at the same time. It seems to clog a little less, but it also seems to maintain RPM better with a stronger tractor. I did notice it was able to cut heavier stuff due to having much heavier knives and probably also due to more HP. If you're not looking to have a nice manicured lawn I suggest you order a set of M-105319M from Flailmaster. They will fit right on the same links as your wings and you can switch back and forth as desired (if desired...). They are the "extreme service" knives. There's advantages and disadvantages to these and you have to weigh the options. The extra weight gives them more momentum, which is a double edged sword because momentum works both directions. They stay spinning better, but they take more to start spinning. If you're running lower HP you may want to consider Flailmaster's FM-7 blades ("heavy duty") so you can get it spinning quicker after a slow-down.

I think because the side slicers don't have the angle to them they will require less HP to run because you're not trying to move air or material up after cutting. Just make sure your blades are sharp, that helps reduce HP used.

 

[def38]

I usually wait until my clover and grass/weed fields are about 8-12 inches before mowing. I have my tilt set at about 10 degrees and seem to have plenty of recirculation of cuttings to provide very good mulching. Even the occasional Buick hubcap gets a ride around the underside several times before being spit out the back. My Titan flail has hammer flails. My guess is that the Chinses flails are knockoffs of some other popular, successful brand (unknown) which does have proper baffling and air circulation at the underside. I get fine mulch when I cut this way and see a nice trail of fine cuttings coming out from under the rear roller. When cutting my Bermuda lawn, the mulching is not as efficient due to the fine grass blades. I usually use the 42" riding mower to cut the 1 acre Bermuda lawn. It does fine but I prefer using the M-F and Titan flail whenever possible.

 

[jonsstihl]

not trying to argue, just respectfully point out my opinion but I just don't see how side slicers generate enough lateral force to overcome the centripetal force acting on the knives at full operating speed. I don't know the math but I do know with the weight of the side slicers turning at several thousand rpm the force required would most likely be in the several hundred pound range if not in the thousands.

example hang one knife from the hanger and it will hang crooked because it will balance its center of gravity under the attachment point. hang two side slicers and they will touch each other and the vertical parts will be straight. there is no way to generate lateral forces to seperate the two knives with a plain flat profile like most typical side slicer knives.

that being said, I have never seen a picture of these airplane wing shaped knives before and would appreciate if someone could post one. all I have seen are plain stamped steel side slicers, scoop knives, or hammers that are in the flail master catalog.