Flail Mower First-time flail mower user, cut quality concerns

[redhead]

Hi. I've recently purchased a 60" Betstco standard duty flail mower (FH EF-155) and the cut quality is poor compared to the 5' rotary mower it replaced. Tractor makes 25 PTO hp. No problem maintaining 540 RPM. Flail is equipped with "Y" grass blades. Cutting height is 5-6".

With the flail, I'm seeing uncut strands of grass and even the odd uncut clump here and there. Mowing with the rear roller in contact with the ground. Experimented with changing the angle of the front of the deck (adjusting the top link) and traveling at different speeds. Neither has had a noticeable effect on the cut quality. I'd really appreciate some suggestions.

 

[redhead]

Probably should add, the grass I'm trying to mow is only 12-18" high and not especially thick ... unfertilized pasture and summer (as opposed to spring) growth

 

[leonz]

Hello redhead,

I want to welcome you as the newest resident member of the "Flail Mower Nations" from Connecticut/Vermont.


How fast are you traveling forward?

Where is the rear roller set on the height adjustment

Is the rear roller on the ground when you are mowing?

We need to know the mowing speed also.

 

[kkimura]

I have the EFGC-155 paired to a Kioti ck2610. I messed around a lot with adjustments. I removed the roller scraper (ditched it) and experimented with the highest and lowest roller positions and I removed all the y blades and sharpened them. At any roller position you can vary the height about an inch plus by adjusting the top link. Currently I'm three bolt holes down from the highest position allowing the blades leave around 2 to 2 1/2 inches. I've been extending the top link to leave a longer cut. I cut in my hst low range with the rpm set at the upper end of the pto range indicator-2250rpm- and I drive slow. I tried to cut long reed canary grass once and it looked bad like you describe. Also the cut is bad in reverse. Better to p/u mower, reverse, drop it and cut going forward. You might get better results by lowering the roller so the knives leave 3 inches of grass length.

 

[redhead]

How fast are you traveling forward?

About 3 mph. HST low range, about 2400 RPM on the tachometer. I have tried slowing way down, and it doesn't seem to make a big difference.

Where is the rear roller set on the height adjustment

Rear roller is set one hole down from highest position

Is the rear roller on the ground when you are mowing?

Affirmative. My 3-point arms are at their lowest position so that the mower will float


Thanks for your reply Leonz

 

[redhead]

Kkimura

Very helpful, thanks. I will mirror your set up and report back tomorrow. I had however hoped to keep the cut height around 5". I worry that it's hard on the turf to cut too short.

Did sharpening the blades make a big difference? I've been hoping to avoid this. How big of a concern is balance, that is, ensuring that the weight of each blade is equal?

 

[StuartDK45SE]

My new flail mower )sharp y knives) doesn't do the greatest job on tall, clumpy weeds. I would say it only cuts them clean with no stragglers about half of the time. My rotary cutter did the same thing. In areas of my pasture with these type weeds, I try to cut in a crisscross pattern to where I am hitting the once cut stragglers again at a 90 angle.

 

[leonz]

OK,

now that I know a bit more about this mower and how you operate it:

What is the recommended PTO Speed for operating this mower



Your mowing height is much too high.

1. Are you using 540 RPM for the PTO Speed?

So much depends on how your side slicer knives were sharpened; meaning they should have been sharpened with a wet well low speed grinder as grinding sharp metal edges that have been heat tempered damages the temper of the metal and it is much easier to damage the cutting edge and it becomes more easily damaged by simple use.

My knifes cutting angle is 37 degrees if I remember correctly.


An economical wet well grinder can be purchased from micromark.com and they were $99.00 plus shipping and tax. This wet well grinder requires that you purchase an angle setter and they can be purchased from woodcraft.com and other resellers


The woodmax site is no longer open and I cannot access it.


Edit:

1. You will not hurt the turf mowing at 2 inches unless you are dealing with a drought anyway.

2. you can mow in a spiral and overlap the mowing to mow it more effectively;
mowing in this way lets you save time, wear and tear brakes on the mule and fuel.

 

[kkimura]

Kkimura

Did sharpening the blades make a big difference? I've been hoping to avoid this. How big of a concern is balance, that is, ensuring that the weight of each blade is equal?

I examined the fresh blades and they were not sharp. Edges were squared off up to an 1/8 inch wide. I knew I was going to clear an area of blackberry vines and saplings and 15' high knotweed so I left the blades until that job was finished. The blades were rounded over (very mild steel). I removed the blades and put a secondary bevel at the edge. I used my bench grinder - don't spend a lot of time as the steel is too mild to hold an edge long. I figured people are knocking chunks off their knives all the time so balance can't be too much of an issue. Just listen for vibration.

I think the problem with leaving the grass long is that it bends too much and the blades can't bite the stem. At any rate, if I leave more than a 4" cut is looks crappy.

 

[ovrszd]

Flail mowers don't like to mow high and/or thin sporadic growth. They actually need to create a vacuum to pull the growth toward the cutters. This is hard to do under the conditions you describe.

Flail mowers are sometimes disappointing in their results.

Hope you get it to work satisfactorily.

 

[redhead]

So I lowered the cut height by one position, 3/5 instead of 4/5, and the cut quality is greatly improved. Not perfect, but acceptable. Thank you all very much for taking the time to help.

At a glance, the blades that came on my unit have a similar edge to what you'd see on a new push mower blade. Hopefully, I can procrastinate on sharpening the 54 individual edges until it becomes a winter project.

 

[redhead]

Flail mowers don't like to mow high and/or thin sporadic growth. They actually need to create a vacuum to pull the growth toward the cutters..

This makes a ton of sense. Insight appreciated

 

[Jack Yuan]

Obviously you bought their EF with this knife,

EF mower is light duty flail mower, I only recommend customer cut grass less than 15 inch height if with flail hammer, less height grass if with the small Y knife you bought.

I suggest you to drive slow, sharpen those Y knife, lower down the roller position. Hope this could help you.

Flail hammer is more suitable for you, but not this Y knife.

 

[leonz]

The closer the flail mower knife is to the sod the more efficient the pressure gradient becomes to create a vacuum to lift the brush up and cut it and then recut it as long as you travel slowly while mowing.


It takes very little time to sharpen flail mower knives with a wet well grinder as neither the side slicer knife nor the cast hammer knife become hot to the touch and one pass with the gauge set at 37 degrees is plenty as long as the knife is clean of grass dust.

This can be down using using a diluted bleach solution with dawn dish soap and a small parts scrub brush with stiff metal bristles.

 

[leonz]

The closer the flail mower knife is to the sod the more efficient the pressure gradient becomes to create a vacuum to lift the brush up and cut it and then recut it as long as you travel slowly while mowing.


It takes very little time to sharpen flail mower knives with a wet well grinder as neither the side slicer knife nor the cast hammer knife become hot to the touch and one pass with the gauge set at 37 degrees is plenty as long as the knife is clean of grass dust.

This can be down using using a diluted bleach solution with dawn dish soap and a small parts scrub brush with stiff metal bristles.


The spacers used to hold the knife pairs in place(that are removed when it is equipped with cast hammers) do not allow the side slicer knife to become a wing and create more lift and a level cut as the knives supplied do not have an oval mounting hole.

 

[TerryR]

It takes very little time to sharpen flail mower knives with a wet well grinder as neither the side slicer knife nor the cast hammer knife become hot to the touch and one pass with the gauge set at 37 degrees is plenty as long as the knife is clean of grass dust.

This can be down using using a diluted bleach solution with dawn dish soap and a small parts scrub brush with stiff metal bristles.

leonz,

No doubt you are right that it takes very little time to sharpen a blade with a wet grinder. But how about removing, washing as you describe, sharpening, and re-mounting 50 of them? Doesn't sound quick to me.

 

[ovrszd]

leonz,

No doubt you are right that it takes very little time to sharpen a blade with a wet grinder. But how about removing, washing as you describe, sharpening, and re-mounting 50 of them? Doesn't sound quick to me.

And it's not. Leonz definition of very little time and mine are different. I guess, in his defense, if he means it takes little time to sharpen one knife I'll give him that. Forgetting the hours involved to disassemble and reassemble the machine and cleaning each knife as described.

 

[leonz]

Hello terry, ovrszd,

I guess I have forgotten how spoiled I have become with the tool less mounting system I have which lets me pull knives and the thatching blades quickly.

I use a lot of hot water with a garden hose to wash the flail mower rotor before I start any work with the knives or the thatching blades.

I still have to purchase new thatching blades as the originals are off the flail mower and look like butter knifes eliminating there effectiveness in dethatching the lawn which is long overdue.

Using a pressure washer the day before if you own one also aids in a faster removal of the cast hammer knives scoop knives and side slicer knives.

When I do a mass extraction and cleaning I have a big bucket of hot water handy with some dawn and a bit of bleach to begin the process of cleaning the side slicers that are still in good condition

I agree it does take time to remove hammer knives or side slicer pairs especially if the threads on the mounting bolts are damaged and the bolt is not double nutted to protect the threads.

Cleaning them and the bolts one at a time helps by removing the fine dust that adheres to the hammer knife and by cleaning the knives before hand extends the life of the grinding wheel by preventing it from becoming plugged with grass dust.

I never really pay any attention to the time it takes its just something I do not have to do very often.

The Vrisimo flail mowers did have a continuous rod that secures the entire knife row and the side slicers could be selectively removed to replace damaged side slicers or to sharpen all the side slicers. I am not sure if they still use this method of anchoring the knife pairs on the mounting
stations.


July 11, 2018 Edit:


My Mathews Company 48 inch Lawn Genie Pick Up Mower has the Original Briggs & Stratton 16 horse power I/C engine with the cast iron sleeve(why they stopped making this I/C engine type I will never understand either.
This lawn Genie Pick up mower has 64 knife mounting stations, 64 pairs of side slicers and 64 thatching knives as standard equipment. Sadly Mathews no longer makes them but parts are still available.

The Beautiful knives this machine came with are no longer made either. I will have to see if Clean Cutter will make them for me as Flail Master was not interested in making 144 of them for me.

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[ovrszd]

Leonz, since you are overdue for a sharpening I would appreciate it if you time the process including the prep cleaning. Inquiring minds want to know. Thanks.