flail mowers waist HP?

[leonz]

The typical flail mower or flail chopper has more cutting edge surface exposed to the grass or brush versus the rotary cutter of any cutting width width as the rotary cutters exposed cutting edge is in actual use half of the mowers width with one mower blade always trailing the first advancing blade.

The flail mower or flail chopper has many more feet of cutting edge exposed doiing the same work at a higher speed of rotation at all times as the flailmower rotor is spinning at a much higher RPM due to the V belt drive or gear drive of a flail chopper.

If anything the flail mower has a higher efficiency simply because it has more cutting edge exposed doing the same work along the entire width of the mower at work.

Each grass slicer or scoop is cutting a small pottion of the grass ahead of it and the grass slicers, scoops, duck bill hammer knives or hammer knives following behind them overlap and remove the portion that is left as the mower advances or reverses with the prime mover.


The flailmower is not an energy hog as the individual knives are using the throw wieght of the knive, knive hanger and rotor as the entire assembly is rotating about axis of the rotor.


In the case of the Mathews Company Lawn Genie and and other European makes of grass mowers with collectors, the rotor consists of a very large
weldment that welded to make a large diameter tube not quite resembling a lawn roller with swiveling metal paddles attached to create additional suction along the entire width of the rotor and also add throw wieght to the rotor shaft that it is attached to to make more efficient use of the grass slicers and dethatching blades in our case.

In our case the flail mower is doing more work per foot of cut with more grass knive edge exposed with the same power as the 60 inch Lawn Genie Pick up mower which is P.T.O., powered as it is rotating the the air paddles to move the grass over the rotor and into the hopper or back down to the ground in the case of heavy brush for pick up later if desired.

In the case of flail choppers the scoop knives act as an air paddle at the same time they are shredding the cotton, cane, corn or potato vine stubble left after harvest.

The flail is not wasting power when used at the 540 R.P.M. speed as the rotor is traveling at a greater velocity than a rotary brush cutter of any size as the throw wieght is used to mow along the entire width of cut with the grass slicer knive, hardened grass slicer knive or grass scoop, duck bill type of flailhammer or a flail hammer as the entire width of cut is utilised at all times.


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Once you go flail you never go back:thumbsup::licking::drool:

 

[Farmwithjunk]

The typical flail mower or flail chopper has more cutting edge surface exposed to the grass or brush versus the rotary cutter of any cutting width width as the rotary cutters exposed cutting edge is in actual use half of the mowers width with one mower blade always trailing the first advancing blade.

The flail mower or flail chopper has many more feet of cutting edge exposed doiing the same work at a higher speed of rotation at all times as the flailmower rotor is spinning at a much higher RPM due to the V belt drive or gear drive of a flail chopper.

If anything the flail mower has a higher efficiency simply because it has more cutting edge exposed doing the same work along the entire width of the mower at work.

Each grass slicer or scoop is cutting a small potrtion of the grass ahead of it and the grass slicers, scoops, duck bill hammer knives or hammer knives following behind them overlap and remove the portion that is left as the mower advances or reverses with the prime mover.


The flailmower is not an energy hog as the individual knives are using the throw wieght of the knive, knive hanger and rotor as the entire assembly is rotating about axis of the rotor.


In the case of the Mathews Company Lawn Genie and and other European makes of grass mowers with collectors, the rotor consists of a very large
weldment that welded to make a large diameter tube not quite resembling a lawn roller with swiveling metal paddles attached to create additional suction along the entire width of the rotor and also add throw wieght to the rotor shaft that it is attached to to make more efficient use of the grass slicers and dethatching blades in our case.

In our case the flail mower is doing more work per foot of cut with more grass knive edge exposed with the same power as the 60 inch Lawn Genie Pick up mower which is P.T.O., powered as it is rotating the the air paddles to move the grass over the rotor and into the hopper or back down to the ground in the case of heavy brush for pick up later if desired.

In the case of flail choppers the scoop knives act as an air paddle at the same time they are shredding the cotton, cane, corn or potato vine stubble left after harvest.

The flail is not wasting power when used at the 540 R.P.M. speed as the rotor is traveling at a greater velocity than a rotary brush cutter of any size as the throw wieght is used to mow along the entire width of cut with the grass slicer knive, hardened grass slicer knive or grass scoop, duck bill type of flailhammer or a flail hammer as the entire width of cut is utilised at all times.


_________________________________________________________________
Once you go flail you never go back:thumbsup::licking::drool:

.......And now for the comedy portion of todays program.............

Puts me in mind of the last "State of the Union Address".

 

[jbooth]

Seems the bait has been taken!!

 

[Marveltone]

Cant... resist... must... jump in...

A rotary cutter arguably uses half the blades at any given time to do the work. Got it.

The flail is more efficient because there is more cutting surface employed at any given time??? Let's see... It's a spinning drum. The knives are attached to said drum. The drum is set at a position parallel to the ground. The knives cut at the lower point of the swing. How much of the lower portion of the drum is low enough to be used? Perhaps 20-25%? The other 75-80% of the time, the knives are spinning around the front, top and back of the drum without cutting anything. Sure, you can argue the knives are shredding the grass, but you can also set up a rotary cutter to shred the grass.

Then there are the inherent friction losses of belts vs. gears. :confused2:

The way I see it, the RC is roughly 50% efficient, while the flail is only 25% at best; probably closer to 20%

Now I've done it!

Joe

 

[leonz]

At any point in the rotation of the rotor, the entire width if the rotor whether it has 3 or four rows of grass slicers has one full width of grass slicer slicing the grass.

Using a 48 inch rotor with 4 rows of grass slicers in the example each row will have 16 pairs of grass slicers and a single grass slicer at opposite ends of the rows covering the entire 48 inch width the following row is opposed in the lacing covering the next portion to be sliced with the following two rows continuing the coverage.

Each knive has 1 1/2 inches of slicing edge exposed to the turf or brush with 3 inches of cutting edge per hanger with 16 pairs of knives and an extra knive provides the row with 49 and 1/2 inches of cutting edge to be used for the 48 inch width. so the flail mower has 199.5 inches of exposed cutting surface versus 24 inches in a finish mower or rotary cutter which is doubled if you count the unexposed edge on the back side of the grass slicer knive.

 

[Argosy]

Not quite, at least on mine. The hammers aren't in straight rows, they rotate around the tube. If you could connect the hammers the line would look like threads on a screw. Sort of like a reel mower broken into segments.

I never really checked it out to see how many cut at any given time, I would guess 4 because there are 4 rows of hammers.

 

[leonz]

Its hard to visualise but think of a a rototiller digging up the ground in the same way as the tiller blades overlap from side to side on the same axis as well.

 

[Marveltone]

Simply put, a 48" rotary cutter will have 48" of matter cut with one simple blade moving in a continual arc from one side, around the front, and to the other. Literally, 50% of the available cutting surface is always at work. What percentage of available cutting edges are at work at any given time on a flail?

Joe

 

[RickB]

.......And now for the comedy portion of todays program.............

Puts me in mind of the last "State of the Union Address".

Wind them up and stand back!

 

[leonz]

Simply put, a 48" rotary cutter will have 48" of matter cut with one simple blade moving in a continual arc from one side, around the front, and to the other. Literally, 50% of the available cutting surface is always at work. What percentage of available cutting edges are at work at any given time on a flail?

Joe

if you have a 48 inch width rotary cutter only one blade is cutting with the other following at all times allowing 24 inches of exposed cutting edge

A flail mower wil have one hundred percent coverage per my previous explanation as the grass slicers overlap due to the grass slicer becoming an airfoil becoming horizontal and achieving the zero degree angle from its fourty five degree angle at rest.

This does not occur on some brands of flail rotors as the knives are restrained vertically and there is a longer cutting edge per knive which eliminates the need to allow the knive to become an airfoil and achieve a zero degree angle.