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.

 

[TheFarmerInAdell]

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.

Take a look at the attached image. The airplane wing is on the left.

I agree about the lateral vs centripetal force and have seen pictures of the side slicers leaving v-shaped groves in a lawn. When you go with a finish mower using the side slicers you over lap and have smaller v's so it isn't apparent, but they don't go flat.

 

[bruceha2000]

I wonder if that "V" is why the Woodmaxx blades also have a center blade.

 

[TheFarmerInAdell]

The center blade will do little if anything to help with that "v". Typically the center blade is for thatching. Woodmax might also use that as an extra mulching blade for sticks and harder materials being cut.

 

[def38]

I prefer these...

Flail Mover Blade, Flail Hammer Blade | Steel Forging


They mistakenly call it a mover blade.

 

[Ricn]

The Woodmaxx I have works well and I do tilt the front up a bit to stop scalping that otherwise happens if setting it flat on the ground. Having the mower tilted up does not cut or mulch as well as when flat so Leonz in my opinion is correct in his assessment on how a flail should be designed or was designed initially and would be great if mine operated while flat and without scalping but it's also not the case here. Like Leonz mentioned, these off-shore flails are different than the older flails and a way of cutting corners perhaps like many things being made these days. For my unit, a model 62H, I had to find a happy medium of tilt whereby the grass is cut satisfactorily while keeping scalping to a minimum. For me, this means keeping most if not all the weight on the roller. My grass is not pristine or very flat having lots on bumps and such but were I cutting something like an estate grass where everything must look pristine I might not be so happy. This Woodmaxx is perfect for my situation while being cost effective to own.

Ricn

 

[leonz]

OK,

The tool less mounting stations on my Mathews Company Lawn Genie Pick Up Mower mower are spring tensioned knife hangers. The wide loop hangers allow the side slicer knives to become horizontal when the flail mower spins up to the operating speed and cut flat. with the tapered side slicer knives.

The Mott folks recommended that the thatching blades were ment to be used alone in each mounting station when dethatching a lawn.

With the Lawn Genie when the thatching blade is placed between the side slicers on the mounting station the side slicers and the flail mower rotor are lowered with the mowing height gauge to permit the thatching blades to dig into the turf.
When this is done the process of thatching begins and it allows the side slicers to mow closer to the ground and lift the thatch and grass up and over the flail mower rotor. In my case the baffle plate is lifted and the air flow is diverted to flow upward into the collection basket for later disposal. The side slicer flail knives also create the aerodynamic lift needed to vacuum the grass and thatch into the coolection hopper with the tapered side slicer knife edge that becomes horizontal due to the ability of the knife pairs to become air foils due to the long mounting slot of the side slicer knife.

When this is done the grass really looks naked with the grooved vacuumed turf and you can spread grass seed, gypsum and lime pellets or hydrated lime to help the lawn and help kill the weeds with the lime pellets or hydrated lime

Again the airplane wing knives ARE WHAT ARE REFERRED TO AS "SCOOP KNIVES". The delta wing configuration is simply a result of the thinner bar stock being formed into shape to create the Scoop Knife after the mounting hole is punched and the knife edge is ground.

The "Scoop Knife" is a "multipurpose flail mower knife" for brush and sod and does not provide a fine finish cut.

 

[standup616]

Flail mowers are not designed to be operated that way. They have to be level to enable them to create the suction needed to lift the clippings up and over the flail mower rotor.

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

Raising the front of the flail mower reduces the ability of the flail mower to work more effectively as the flail mower shroud and flail knives work together.

The flail mower shroud acts as an air duct with a limited number of cubic feet within the shroud to let the knives move the air entering the shroud from the front of the mower and also when making second passes to recut the brush and good grass clippings.

The Mathews Company Lawn Genie flail mowers used air paddles to aid in lifting the clippings up and over the flail mower rotor more efficiently and the air paddles also aided in blowing the clippings into the collection baskets of all three models of lawn genies. Sadly these flail mowers are no longer made but after 30 years parts are replacement parts are still available.

Someone else has heard of a lawn genie! I love my seriously abused and fabricobbled back together lawn genie! I have 3 (paw inlaw has one on loan) mc-36s. Have an 11hp honda on my running one, welded washers on ring end of my blades and welded/ground the grove in the hangers to keep from losing everything and made new fan blades when they break. When i lived next to the trailer park, the lawn genie was only thing that kept their garbage they threw over the fence in check and ate the sycamore tree leaves...Glad I sold that place 20 year ago. I am looking for an 8ft flail to run on the M7060 I ordered thats arriving in November they tell me

 

[leonz]

Hellostandup616,

Start looking at tractor house, auction time and iron planet for a used JD25A, 290 or 390 flailmower(8 foot cut). you should also check with the JD dealers in a wide radius as they may have used 290's in as trades(7 foot cut) or they know where some used ones are as the dealers also have a network for used JD machinery and JD implements.

Another option is to check with The Vrisimo folks in California to see if they have taken in any seven or eight foot flail mowers in on trade as they go through them completely and sell them as guaranteed units.

ALL the repair parts are still available from Mathews for the Lawn Genie Pick Up mowers!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Sadly though :thumbdown: the beautiful tapered side slicer knives that they came with are no longer available-I am working on that fact though.

The smallest Peruzzo PTO Pick Up Flail Mowers are 12K before they leave the dock in Italy; your new mule can handle one with ease and the larger model is also a front castered unit with rear tires to go along with the rear roller has a hydraulic lift collection basket just the 60 inch Lawn Genie Pick Up Mower.


Sent you a pm.

 

[TheFarmerInAdell]

The wide loop hangers allow the side slicer knives to become horizontal when the flail mower spins up to the operating speed and cut flat. with the tapered side slicer knives.

I have a hard time believing this. The laws of physics disagree with this theory. Do you have any proof that this actually happens? I've seen nice lawns mowed with side slicers and you can see the "V" shape left by the side slicers proving that it doesn't go horizontal.

Again the airplane wing knives ARE WHAT ARE REFERRED TO AS "SCOOP KNIVES". The delta wing configuration is simply a result of the thinner bar stock being formed into shape to create the Scoop Knife after the mounting hole is punched and the knife edge is ground.

The "Scoop Knife" is a "multipurpose flail mower knife" for brush and sod and does not provide a fine finish cut.

Airplane wings are not scoop knives. They are made differently and hang differently. The scoop has a single blade that goes all the way across the front, parallel to the ground and sits out front of the hanging point. The airplane wing has 2 small blades that are parallel but sit directly below the hanging point. Airplane wings are specific to Ford 917 (and I think 907 and possibly the Ford made Bush Hog) mowers. The design and manufacturing of the two are different.

And the scoop knives provide a good fine finish cut if they are sharp. Someone else (I think on this forum) swapped side slicer for scoop knives on a Caroni and got a much better cut than the rough cut side slicers.

Each type of knife has it's place. Hammers are good for cutting anything, including rocks, but don't leave superior finish. Large side slicers are good for rough cutting, but leave "V" shapes. Scoops are good for rough and finish cutting (but not the best at either). Small side slicers are good for fine finish cutting due to the number of blades and overlapping.

 

[leonz]

The airplane wings of the old jet aircraft like the B58 valkyrie and the jet aircraft fighters used during the vietnam war have the delta wing shape which resembles the stamped and folded scoop knives.

The sawtooth pattern noticed in good grass sod occurs due to mowing shorter and the mounting stations securing the side slicer knives in the vertical position as the mounting holes for the knives are punched circular mounting holes.

The proof of this "theory" is my 48 inch lawn Genie Pick up mower in my backyard under a waterproof tarpaulin.

The sharp long tapered edge of the old style side slicer knives creates lift and as a result the knives become horizontal when the flail mower rotor reaches 2200 rpm plus as the slotted mounting holes allow the knife to slide outward do to the centrifugal force and become airborne even though they are secure in the mounting station as it is a wide loop allowing the knives to become near horizontal due to the long tapered edge of the side slicer knife that is much longer than the current side slicer knives that are available.

If you look at the old gas powered carrier based aircraft they have the folding wings and when you see how they fold out flat you will see what I am describing as these airplane wings look like these flail mower knives when folded out and the tapered side slicer knives are horizontal.