Flail Mower Let's talk flail mowers

[Ricn]

YES, ME. My 2501 pulls the woodmaxx 60 inch just fine cutting very tall reed canary grass. This setup is much more than I thought it would be, very happy.

Ricn

 

[TheFarmerInAdell]

Another question..... How often do you guys need to replace blades or hangers on your flails? Not because they are full, but because they've broken off and are missing????

For example, I have 7 missing from mowing maybe 4 acres yesterday. This to me seems like an incredibly high number to lose.

Look where your top link is mounted to the tractor. Are there holes that you can lower the top link position? I did this and it dramatically reduced my scalping. The mower now tips as it goes up and down over hills due to the altered geometry of the top link.

Are you tearing out the hole in the mounting flange on the rotor or just losing your cutter and link? Or are your nuts loosening on the hanger (the part that bolts to the rotor flange)? What did you lose and what is still there? that will give you a good indication of what is going on. If you tear out your mounting hole in the flange either the flange is weak or you're doing some serious damage when you mow. If you're losing the whole assembly then likely your nuts are coming loose. If you lose just the knife you are probably hitting stuff. If you lose the link as well then I have no idea what went wrong there.

I lost a few knives when I sucked up a hidden 4" tree branch. Otherwise I don't lose knives. On my old 917 I saw a few of the holes in rotor flange were torn out before I got it. Check if this is happening.

 

[JWR]

My 3 point lift arms are not 'bottomed out' when my mower is mounted on flat ground. So if you imagine the tractor backed up to the edge of a cliff, the mower would drop maybe a foot before 'bottoming out' the lift arms and hanging in mid air.

So I'm thinking if I set my lift arms up so that this settling didn't occur, it might help with the scalping.

This mower has been a real PITA. It cuts nice but I'm kinda wishing I just bought a nice brush hog.

A bush hog is simply far more durable and less "high maintenance" than a flail. I like the flail, feel I can mow a smoother consistent mulched looking path left behind it, and seems faster (7.5 ft flail) than my 7 ft hog more so than the 6" difference. That's great in grassy places where there is little heavy debris. In a pasture field with rocks here and there, fence post sized limbs and debris in 20 places per acre, etc. the bush hog keeps right on going and the flail makes me stop and replace knives and hanger clevises a couple of times per day of mowing -- and that's when I am super careful to lift the flail over any visible limbs that are too large. I'm getting ready to put my nice hefty trouble free hog back on next trip to the farm.

Now about all these scalping reports -- one guy saying he was missing 7 knives !!?? ****, ONE knife pair missing on my age old Alamo SD88 makes the vibration so bad I know darn well I have to stop and fix it. Seven is a severe exaggeration or just crazy. I am pretty sure that most if not all flail mowers we speak of here have a common design feature -- namely a trailing roller in back with a rotor carrying knives that "hits the grass first." That design inherently means that your TOP LINK is what sets the mowing height (given that you have the roller bolted in at some workable height and are not screwing with it often.) So those with "scalping" concerns need to run their top links back/longer which raises the flails higher off the ground. I love my hydraulic top link for many reasons and that is one more -- allows me to adjust cutting height from the driver's seat.

Other discussion about lower lift arm adjustments, limiting their travel, etc. to me are irrelevant and have little or no relationship to scalping issues. Also the discussion about skids seems off the mark to me too since my skids rarely touch the ground and normally ride around 2-3 inches above the soil. My opinions of course...

Bouncing around here a bit -- this thread is more like a 12 guage with bird shot than it is like my 243, shots going everywhere -- friend FarmerInAdell says "If you lose just the knife you are probably hitting stuff." and I agree 100%. That's exactly what happens to me. But FarmerInAdell also says he lowered the top link position in the multi-hole "beam" that anchors the top link and found dramatically reduced scalping (??) That should not make any difference. In his experience apparently it did make a big difference, but I can't understand how it makes any difference in geometry that logically affects scalping. Maybe he or others on here can explain that one ?

 

[TheFarmerInAdell]

Bouncing around here a bit -- this thread is more like a 12 guage with bird shot than it is like my 243, shots going everywhere -- friend FarmerInAdell says "If you lose just the knife you are probably hitting stuff." and I agree 100%. That's exactly what happens to me. But FarmerInAdell also says he lowered the top link position in the multi-hole "beam" that anchors the top link and found dramatically reduced scalping (??) That should not make any difference. In his experience apparently it did make a big difference, but I can't understand how it makes any difference in geometry that logically affects scalping. Maybe he or others on here can explain that one ?

When going over my ditches and hills the mower tilts as the 3 point arms go up and down. So when the tractor is on the level but the mower is still on it's way out of the ditch the mower is tilted to the angle of the ditch instead of being level with the tractor. And when I'm going down a hill and the tractor makes it to level the mower is still on the hill, it tilts to the angle of the hill. Lowering the top link at the tractor mounting point will effect the arc of travel of the top link compared to the lower links. Instead of the mower staying parallel with the tractor it tips with the 3 point lift arms a bit. Think of a fork lift vs front end loader with the way the bucket or forks move.

 

[JWR]

When going over my ditches and hills the mower tilts as the 3 point arms go up and down. So when the tractor is on the level but the mower is still on it's way out of the ditch the mower is tilted to the angle of the ditch instead of being level with the tractor. And when I'm going down a hill and the tractor makes it to level the mower is still on the hill, it tilts to the angle of the hill. Lowering the top link at the tractor mounting point will effect the arc of travel of the top link compared to the lower links. Instead of the mower staying parallel with the tractor it tips with the 3 point lift arms a bit. Think of a fork lift vs front end loader with the way the bucket or forks move.

OK, I can see that. Now that I understand the change in the arc, I'm still surprised it makes that much difference in the scalping. Interesting.

 

[ericm979]

Try measuring the angle of the mower at different points as it's raised an lowered by the 3pt. When you get to where the top link is level, it will have the mower tipped back as far as it will go. When above or below that point, the top link's angle will pull the top of the mower in which will reduce cutting height. The 3pt arms' angle will have a similar effect with the bottom of the mower but less because they are longer.

 

[arto98607]

I find this discussion about scalping problems with flail mower interesting!



I have used my 60" Ford 917L now three times for mowing our pasture and a forest. The pasture has reasonably level ground and the flail does a nice job mowing it but the forest area has several nasty uneven areas where the flail mower has worked beautifully so far and without any scalping at all. It's set to about 3.5 inch cutting height.


My 48" JD brush hog has always given some trouble with scalping in the uneven forest areas but it can handle it no problem, I just don't like the looks of it!

 

[jthibodeau89]

View attachment 665599

The hanger on the right end is partially dislodged and needs to be secured before running again. The mounting tab on the rotor appears to be bent already. Be very careful if bending back not to crack the weld.

I prefer the flail mounting method on my JD mowers. I.E. continuous axial rib with formed flat straps that secure D-ring blade hangers. The down side is that the corners of ther blades can hit the rotor, dullling them. But no individual tab welds to break.

 

[JWR]

View attachment 665599

The hanger on the right end is partially dislodged and needs to be secured before running again. The mounting tab on the rotor appears to be bent already. Be very careful if bending back not to crack the weld.

I prefer the flail mounting method on my JD mowers. I.E. continuous axial rib with formed flat straps that secure D-ring blade hangers. The down side is that the corners of ther blades can hit the rotor, dullling them. But no individual tab welds to break.

This machine has identical hangers, knives, clevises and pins to my aged Alamo SHD88. Typical I hear of roadside maintenance equipment. VERY repairable and maintainable. If I were you (unless you do your own welding) I'd take it to a welding shop and have the left support heated and straightened and just put it all back together. I can't see the dislodged right side hanger but of course weld that back solid to the big rotor shaft too. Not a problem.

I'm not familiar with the JD mounting method -- got any pictures of that?

 

[TheFarmerInAdell]

The only scalping issues I've had is when the mower drops below the tractor while mowing my ditches perpendicularly. That's where moving the top link on the tractor side helped. The other side of that is when the mower is higher than the tractor it was leaving the grass long, again solved by the top link adjustment. I would also like to note that I use this mower for my lawn so I leave it at about 2-3". If I have time this weekend I'll try to get pictures or video to show how this works. In a perfect world I'd add wheels to the front of the mower and float the top link. I just haven't had the ambition to do that yet.