Flail mower first try = terrible cut… SOLVED

[S854]

I mowed a small section of field grass/alfalfa/weeds the other day with my new 60” Betstco flail… what was left standing behind the mower wasn’t anything like the videos I’ve seen, where the mower absolutely demolishes anything and everything it runs over… leaving a nice, mulched trail behind…

The grasses and small weeds get taken off pretty well (and mulched) but the flowering alfalfa and any taller, thicker stem weeds leave a foot-tall stem standing… going back over the stems usually takes them down but I’d rather NOT mow our 20 acres twice…

I have read the majority of the “Let’s Talk Flail Mowers” without coming across a solution to my issue… (it’s actually a rather entertaining tome!)

I mowed in low range, 540 PTO engine speed on my Kioti CK2610 HST, trying various ground speeds with the pedal… no difference… (I even tried the lower PTO engine speed just for kicks)

Tried extending and retracting my hydraulic top link… no difference…

I have the mower set at its highest setting (roller and skids) as we have numerous large rocks in our fields which I’d like to avoid…

I checked the belt tension during the initial setup (gonna check it again this morning)… All the bearings are greased, all the bolts are tight…

Raising or lowering the lift arms slightly also made no difference…

I‘m at a loss… it’s something simple, I’m sure but I don’t know what else to “adjust”…

 

[Locoweed]

Mine typically cuts much better when mowing shorter.

 

[K5lwq]

Any pictures? The cut gets better the lower you can mow. Also using the top link to adjust the height helps.

 

[Hay Dude]

running backwards (wrong direction)?

 

[scootr]

Which hammers did you get?
I have the large brush cutting type and they will leave some small stuff standing.

 

[leonz]

I mowed a small section of field grass/alfalfa/weeds the other day with my new 60” Betstco flail… what was left standing behind the mower wasn’t anything like the videos I’ve seen, where the mower absolutely demolishes anything and everything it runs over… leaving a nice, mulched trail behind…

The grasses and small weeds get taken off pretty well (and mulched) but the flowering alfalfa and any taller, thicker stem weeds leave a foot-tall stem standing… going back over the stems usually takes them down but I’d rather NOT mow our 20 acres twice…

I have read the majority of the “Let’s Talk Flail Mowers” without coming across a solution to my issue… (it’s actually a rather entertaining tome!)

I mowed in low range, 540 PTO engine speed on my Kioti CK2610 HST, trying various ground speeds with the pedal… no difference… (I even tried the lower PTO engine speed just for kicks)

Tried extending and retracting my hydraulic top link… no difference…

I have the mower set at its highest setting (roller and skids) as we have numerous large rocks in our fields which I’d like to avoid…

I checked the belt tension during the initial setup (gonna check it again this morning)… All the bearings are greased, all the bolts are tight…

Raising or lowering the lift arms slightly also made no difference…

I‘m at a loss… it’s something simple, I’m sure but I don’t know what else to “adjust”…

OK,

If the flail mower does not sound like a shop vac vacuum cleaner it is not creating the amount of
pressure gradient/suction to lift the clippings up and over the flail mower rotor and the flail mower
rotor is not spinning at 2,200 RPM+.

Tall, thick, dense brush requires the user to operate at the lowest forward travel speed
at the lowest mower setting with the engine at the 540 RPM rear PTO engine setting.
Tall, thick, dense brush mowing using a small tractor requires the user to operate the
flail mower in an overlapping mowing method to recut the material and catch the
stringers/stragglers.

What is the low range speed on your mule?

Is your flail mower equipped with side slicer or the scoop/spoon knives??

A flail mower operates best with the roller at its highest mounting point (lowest mowing height setting)
which is the top mounting/height adjustment holes in the side weldments of the mower.

The skids should not touch the ground, their only job is to protect the flail mower rotor, knife hangers and knives/hammers.

Are the V belts on your flail mower tightened by hand using a flat snubber pulley?

If you are mowing 20 acres only occasionally you will not control the invasive plants like ragweed, water hemp,
thistle, poison ivy, poison sumac very well and mowing will be harder to do.

If you mow the 20 acres in 4-5 acre blocks every 2 weeks at a low cutting height you can manage the mowing much more easily.

You will be better off using the Massey Ferguson 135 for this mowing if it is in operating condition.

 

[TerryR]

I mowed a small section of field grass/alfalfa/weeds the other day with my new 60” Betstco flail… what was left standing behind the mower wasn’t anything like the videos I’ve seen, where the mower absolutely demolishes anything and everything it runs over… leaving a nice, mulched trail behind…

The grasses and small weeds get taken off pretty well (and mulched) but the flowering alfalfa and any taller, thicker stem weeds leave a foot-tall stem standing…

Yes, that's a flail mower.

They do not do well with tall stem weeds. the front of the housing, especially if there is a stiff guard hanging down, pushes them over and holds them down while the mower rides over them. See Can a Flail Mower Cut Tall Weeds?

My solution was to replace the stiff belt front guard with a chain guard, which helps a lot. See Chain Guards for Flail Mower? on the second page.

The other issue is a flail does a poor job of picking up taller stuff after the tractor wheels run over it. Then it pops back up in a couple of hours. I use my mower offset so it mostly doesn't have to deal with that to solve this issue.

 

[diesel85]

I typically cut 1-2' grasses and weeds with my flail mower and it does occasionally leave stragglers, but nothing is perfect. Does way better than a rotary rough cut mower and is easier on the machine than trying to use a finish mower.

My Woodmaxx 62" has side slicer or Y knives, or grass knives whatever you want to call them.

Does a phenomenal job mowing my lawn to a golf course look I can admit to that.

 

[S854]

The right side of the yellow line was mowed by Julie on her new Bad Boy... I think she did a nice job for her first time in the seat... there was alfalfa where she mowed, too...

Inside the red circles are what's left of 2-3' diameter alfalfa bushes where I mowed with the flail...

Outlined in red is a stripped alfalfa stalk... again, about 2-3' long...

Gonna try to answer a few questions here...

I varied my ground speed from barely moving to a brisk walking speed... the flail does sound somewhat like a shop vac ... the one odd thing I noticed was, when I first spun the mower up to test it in the garage, it sounded "good"... when I shut it down, it continued to spin for a few seconds then, as the rotor slowed, I got some loud clanging as the hammers were no longer held by centrifugal force and came into contact with the rotor... after actually using the mower on my test strip, when I shut it down the clanginig was greatly diminished... I'm not sure if that's because of some weeds which may have wrapped around the rotor or what... this just occurred to me as I was reading and replying to posts here...

Gonna check further into this when I adjust the roller/skids/belt tension...

I have "hammer" flails...

The front guard on Betestco flails consists of 20-30 sections of sheet metal... all about 1 1/2" X 2"... hanging like flaps from the front of the mower... (I'm going from vague memory here... didn't pay too much attention to the moveable guards other than the fact I thought "that's cool"...)

I'm getting ready to bring the mower into the garage for some adjustments... gonna lower the roller to it's lowest setting (I believe there's 2 choices)... I'll also lower the skids back to the "factory setting"...

With these two changes I'll be able to get a closer cut... and, hopefully, be able to lift the mower when I come across one of the larger obstacles (rocks, ant hills) in our field...

 

[diesel85]

You could always pull out the flapper rod, and replace the flaps with chain. I failed to mention my Woodmaxx has chains for guard instead of the metal flaps.

 

[S854]

You could always pull out the flapper rod, and replace the flaps with chain. I failed to mention my Woodmaxx has chains for guard instead of the metal flaps.

That's on my list of "Things I May Try" if I can't get this going to my satisfaction... Hooking up to the Massey is also on the T.I.M.T. list...

How long are the chains on your Woodmaxx?

 

[kenmbz]

I have the 48" model and mow at about 3" bottom of hammers to ground, Lifting over some objects and do not get the same issue, even with small blackberry and autumn olive and the crazy stiltgrass.

Make sure your tilt is set right with the top link too.
Sometimes I lift the flail and back into larger weeds and drop the flail on them, but that is for much larger than what it looks like you are trying to mow.

On a flat surface, measure bottom most hammer to ground and let us know distance.
Be careful of rocks, chipped a few hammers hitting hidden ones.

 

[S854]

I have the 48" model and mow at about 3" bottom of hammers to ground...

...Make sure your tilt is set right with the top link too...

From what I've been able to gather, tilting the mower back, by extending the top link, increases the cut length...

After I lower the roller/skids I should be able to get to the 3" mark you suggest by varying the length of my hydraulic top link... No?

If that works, I'll try to raise the mower up to match the 4.5" cut left by Julie's mower... see if it still works...

Guess this is a Work-In-Progress...

I'll report back...

 

[K5lwq]

The right side of the yellow line was mowed by Julie on her new Bad Boy... I think she did a nice job for her first time in the seat... there was alfalfa where she mowed, too...

Inside the red circles are what's left of 2-3' diameter alfalfa bushes where I mowed with the flail...View attachment 809033Outlined in red is a stripped alfalfa stalk... again, about 2-3' long...
View attachment 809034

Gonna try to answer a few questions here...

I varied my ground speed from barely moving to a brisk walking speed... the flail does sound somewhat like a shop vac ... the one odd thing I noticed was, when I first spun the mower up to test it in the garage, it sounded "good"... when I shut it down, it continued to spin for a few seconds then, as the rotor slowed, I got some loud clanging as the hammers were no longer held by centrifugal force and came into contact with the rotor... after actually using the mower on my test strip, when I shut it down the clanginig was greatly diminished... I'm not sure if that's because of some weeds which may have wrapped around the rotor or what... this just occurred to me as I was reading and replying to posts here...

Gonna check further into this when I adjust the roller/skids/belt tension...

I have "hammer" flails...

The front guard on Betestco flails consists of 20-30 sections of sheet metal... all about 1 1/2" X 2"... hanging like flaps from the front of the mower... (I'm going from vague memory here... didn't pay too much attention to the moveable guards other than the fact I thought "that's cool"...)

I'm getting ready to bring the mower into the garage for some adjustments... gonna lower the roller to it's lowest setting (I believe there's 2 choices)... I'll also lower the skids back to the "factory setting"...

With these two changes I'll be able to get a closer cut... and, hopefully, be able to lift the mower when I come across one of the larger obstacles (rocks, ant hills) in our field...

A couple of observations from this post.

1. It is apparent that the Bad Boy‘s deck was set an inch or two lower than the flail cut.

2. A flail is not going to give the same finish cut as a zero turn so your expectations may be a little high.

3. How tall was this field to begin with? If it was really tall, mowing again a few days later would help then mowing mow frequently.

 

[ptsg]

Might be a dumb question but are the flails/hammers pointing the right direction?

 

[S854]

We have been experiencing an “extended spring” here in western Montana… the rain and cool weather has stuck around… causing our fields to grow more than usual… best guess is about 3’ tall…

I may have to mow twice… probably not the entire 20 acres this year, just the stuff closest to the house… leave the rest with stubble… I can live with that…

im gonna check out the mower thoroughly… including direction of rotation and hammer orientation…

 

[K5lwq]

We have been experiencing an “extended spring” here in western Montana… the rain and cool weather has stuck around… causing our fields to grow more than usual… best guess is about 3’ tall…

I may have to mow twice… probably not the entire 20 acres this year, just the stuff closest to the house… leave the rest with stubble… I can live with that…

im gonna check out the mower thoroughly… including direction of rotation and hammer orientation…

That explains some of the issues. Mowing lower and more frequently will give a lot better result. But when mowing taller stuff I go slower and usually am happy with one pass on stuff I do not care much about. If I don’t like it I go over it again a few days later.

Here is a picture of an area that I only mowed once this year with my flail. This was about 3’ tall and went over only once. But the mower is set for about 2-1/2 inches.

 

[TerryR]

I'm getting ready to bring the mower into the garage for some adjustments... gonna lower the roller to it's lowest setting (I believe there's 2 choices)... I'll also lower the skids back to the "factory setting"...

With these two changes I'll be able to get a closer cut... and, hopefully, be able to lift the mower when I come across one of the larger obstacles (rocks, ant hills) in our field...

From my experience, I can tell you that lowering the mower will not help with the stiff weeds, but will make it worse because they will be pushed over more and will lay on the ground below the blades. About all you will accomplish is hit more rocks and dull the hammers. Get ready to sharpen them.

What you need to do to cut them is create more opening in front of the blades. Adjusting so the front is higher may help some, but I couldn't tell much difference when I tried that. The only thing that helped was making the front guard more "transparent" to the weeds.

As many have said, a flail only really works well if you cut often. The corollary, seldom stated, is they don't work well if you only cut a couple times a year. I only mow twice a year. I replaced my rotary cutter with a flail only because mine can be offset past the tractor tires and thus doesn't have to deal with stuff mashed down by the tractor. It wasn't because it cuts better, because it aside from that, it actually doesn't do as good a job with tall material.

 

[diesel85]

That's on my list of "Things I May Try" if I can't get this going to my satisfaction... Hooking up to the Massey is also on the T.I.M.T. list...

How long are the chains on your Woodmaxx?

I just measured, and they are 6" chains from the rod.

 

[leonz]

Might be a dumb question but are the flails/hammers pointing the right direction?

Scoop/spoon/hammer knives face the rear wheels, side slicer knives have 2 cutting edges.