Pairing Flail Mower Size And Cutting Conditions To Tractor PTO Horsepower

[Cahaba Valley Farm]

Yes you would be correct. I don't know much of anything.

What I do know, flails have their place as well as rotary, finish mower, reel mowers, drum mowers and even a sickle bar. But if speed is your concern, you can run a larger rotary faster than you can a flail.

If you need an off set mower, or concerned with throwing rocks or you like the finish look of a flail then time is not as big of a concern.

If the finish look is what you want then a finish or reel mower might be more appropriate.

Flails requires more time to service and have more moving parts. They are more expensive to purchase and maintain.

Bottom line for me is you went through some process to determine a flail is right for your situation. Just apply that same logic to determine what size you need.

K5lwq, the reason I chose to go with a flail mower is because I didn't want to have to use two different mowers to cut my grass. With a flail mower you can cut any height of grass and still get a finish look.

I have already determined the size of flail mower that I want to go with which is a 6 foot. I just need it to cover the width of the rear tires.

 

[Cahaba Valley Farm]

One reason for such a wide range of hp recommendation is the dumb user. Not calling you dumb. Have you seen the post on the operator who got killed by a JD rollover due to no rear ballast and sued JD and won? The owners manuals are very clear on safe loader use. But dumb or in to big a hurry to read the manual or the lack of common sense happens so the companies have to try to protect themselves from those people. In all honestly we all can be one of those if not careful, me myself.

For starters it is a pto powered implement so you are working with the PTO hp and not the gross engine or net engine, only the pto hp. Now the range is due to the wide range of what can do with that mower. A flail mower can be operated in a wide range of circumstances. You can travel very slow or say 8 miles per hour. Big difference in the hp needed with the speed difference so if you will be mowing fast high hp needs. The density of what you are mowing,thin less hp of course thick more hp. Same with the height of what you are mowing, short needs less hp than does tall as flail mower does mulch what you are mowing more so than a rotary mower will.

I am in process of matching a new flail mower to a new to me tractor and with my experience am going with about of 75% of the max hp recommended. Why, for one thing I want that wide of mower to reach my ditch banks will be mowing and the other is the small amount of time I will be in heavy cutting don't mind traveling slow. Matter of fact I suggest very much from safety with any type of mower to cut slower in heavier crops.

Most of my flail use has been on boom mowers and very little with a flail mower on grass. I am very use to running in the lowest gear I have and still feel like I am flying due to all the operating to miss the tree that is huge to the changing terrain tilting mower up and down.

You will find the same process for any implement that tills also. Take a simple disk, the trash being cut, the type of dirt, the moisture level, the speed you want to run and the type of tires and ballast it has. Way over kill with hp is a waste but way low in hp is work not done and great aggravation.

Oh just thought of one big thing to consider, the result you want. Not with all implements for certain but with mowers or tillage their usually a speed at which if you exceed no machine with no amount of hp can produce the results you want. Any mower has a max speed for good results and tip speed comes into play there. You get that from the mower company. In all this you be sure you then run the tractor to get the recommend pto speed for the mower. The pto must be at the rated speed and you use the gears to get the right ground speed, not the throttle.

Hey kthompson, thanks for joining the discussion. I have read many of your posts over the years and always appreciated your thoughtful and helpful responses to different posters. You seem to always be very positive and encouraging so it's nice to have you join in.

You caught my attention when you said you're going with 75% of the max recommended hp. What is the recommended hp of the flail you are considering and how did you arrive at that conclusion?

 

[kthompson]

Hey kthompson, thanks for joining the discussion. I have read many of your posts over the years and always appreciated your thoughtful and helpful responses to different posters. You seem to always be very positive and encouraging so it's nice to have you join in.

You caught my attention when you said you're going with 75% of the max recommended hp. What is the recommended hp of the flail you are considering and how did you arrive at that conclusion?

Thanks for those kind words. Well it was a careful thought, lol. Not really. I am in down sizing mode. Time to leave farming. My tractor needs are totally changing and looking to go with such as JD 4066 or Kubota L6060. Need much heavier tractor for my boom flail mower so looking at getting an offset flail mower that operates with two hyd cylinders to swing it and tilt up and down. I need a mower that can be used to trim under trees around fields, ditch and pond banks and also tilt down to cut the inside of the ditches and pond bank. In all that having to work tractor capacity, lift category, and range of the offset to reach inside the ditch and pond banks. To get the reach I need best mower I found suggest 30 to 50 hp. Those tractors are hitting the full 50 hp for the pto, the Yanmar I really was leaning to did not hit the 50 hp. (I really like the cab on the Yanmar and yes their transmission but a thread on here about service issues on a Yanmar has turned me off. Support is the most important feature of any tractor or any machine there is to me.)

Even at 75% of max recommend hp for my needs felt that I would safe considering how little should be mowing that heavy a load going real slow would be nonissue.

Not aware what kind of tractor you have nor your mowing needs. All that comes into consideration. Think on the reality of your needs, will you being mowing a lot and often? If so you need to be very near or ever over on hp by some. If you are mowing really heavy even at slow speed may ought to be at max hp still. If your tractor has an eco pto where you can have option to run lower engine speed for light pto jobs then go with around max hp as in heavy cutting you can run higher engine to get max torque or run lower engine rpms to save fuel and engine on lighter cutting.

Of course don't miss what has been said here, you can always narrow the width you are mowing, well most of the time. Some times that is not possible.

 

[Cahaba Valley Farm]

Thanks for those kind words. Well it was a careful thought, lol. Not really. I am in down sizing mode. Time to leave farming. My tractor needs are totally changing and looking to go with such as JD 4066 or Kubota L6060. Need much heavier tractor for my boom flail mower so looking at getting an offset flail mower that operates with two hyd cylinders to swing it and tilt up and down. I need a mower that can be used to trim under trees around fields, ditch and pond banks and also tilt down to cut the inside of the ditches and pond bank. In all that having to work tractor capacity, lift category, and range of the offset to reach inside the ditch and pond banks. To get the reach I need best mower I found suggest 30 to 50 hp. Those tractors are hitting the full 50 hp for the pto, the Yanmar I really was leaning to did not hit the 50 hp. (I really like the cab on the Yanmar and yes their transmission but a thread on here about service issues on a Yanmar has turned me off. Support is the most important feature of any tractor or any machine there is to me.)

Even at 75% of max recommend hp for my needs felt that I would safe considering how little should be mowing that heavy a load going real slow would be nonissue.

Not aware what kind of tractor you have nor your mowing needs. All that comes into consideration. Think on the reality of your needs, will you being mowing a lot and often? If so you need to be very near or ever over on hp by some. If you are mowing really heavy even at slow speed may ought to be at max hp still. If your tractor has an eco pto where you can have option to run lower engine speed for light pto jobs then go with around max hp as in heavy cutting you can run higher engine to get max torque or run lower engine rpms to save fuel and engine on lighter cutting.

Of course don't miss what has been said here, you can always narrow the width you are mowing, well most of the time. Some times that is not possible.

You bring out some really good points for me to consider. :scratchchin: The 4066 is actually one of the tractors that I am seriously considering, so what a small world. You made a great point about ePTO but the problem is the 4 series tractors don't have that capability and I have been stuck wondering if the 4066 is too much for what I am doing. :confused3:

 

[Cahaba Valley Farm]

Based on all the replies that I have gotten so far from everyone that took the time to comment, it sounds like the only way to solve this mystery is to get the opinion of an experienced operator or demo the product to be sure of what you need. Flail mowers are so niche that not many people have experience with them and when you add on top of that a model of flail mower that not anyone on TBN has, it just becomes practically impossible to make an educated guess. However, I do have a contact that I am in touch with that is very experienced with flail mowers and has actually been selling them for over 30 years. I sent him some pictures of my property early this morning and are waiting for a reply back from him. If and when I hear back from him I will be sure to let all of you know what he says.

 

[zonedar]

:thumbsup:

 

[Mike 1734E]

Greetings to all of you out there. For the last several months I have been working and researching every day to find an answer to this question: How do you correctly pair a particular size flail mower for a particular type of cutting conditions to a particular tractor's PTO power output? I have gone as far as contacting several tractor dealerships, flail mower manufacturers and even tried asking particular knowledgeable members in the big flail mower thread this question with no satisfactory answer given to date. If there is anyone out there on this forum that knows the answer to this question please comment so the 8th wonder of the world can be solved.

See the product compatability tool on the bottom of this web page PTO Flail Mowers | Flail Mower | Hydraulic Flail Mower | 3-Point Hitch Mower | Finish Mower Mowers | Tractor Flail Mower | WoodMaxx Flail Mower |

 

[leonz]

Based on all the replies that I have gotten so far from everyone that took the time to comment, it sounds like the only way to solve this mystery is to get the opinion of an experienced operator or demo the product to be sure of what you need. Flail mowers are so niche that not many people have experience with them and when you add on top of that a model of flail mower that not anyone on TBN has, it just becomes practically impossible to make an educated guess. However, I do have a contact that I am in touch with that is very experienced with flail mowers and has actually been selling them for over 30 years. I sent him some pictures of my property early this morning and are waiting for a reply back from him. If and when I hear back from him I will be sure to let all of you know what he says.

As I have written about this extensively on the forum you have to a decision tree
if you want to come to a conclusion and then use an upside down decision tree to
validate it. Another avenue is the Ben Franklin close which is less precise.

No one is going to demo a flail shredder for you.

You will only have a finished look mowing at a 2 inch height flail shredder mower
with side slicers will be unable create the pressure gradient/suction you need to cut and
recut the clippings if it is set above the 2 inch cutting height.

Every branch of a decision tree is simply part of the puzzle to achieve the end.

You may very well find that renting power for a month and buying a very large
flail shredder with heavy side slicer knives will cost you much less money as you
will be able to have a 2 inch cut for all the workload you think you may have.

 

[scootr]

I have a Kubota MX5200 which makes 45 hp at the PTO. I use a 7 ft offset flail with 4 inch hammers. I have no power issues. The offset allows me to cut closer to the fence without running over the fence. And once the fence pass is made I turn around and mow in the opposite direction keeping only one wheel in the uncut material unlike my Brush hog which keeps both wheels in the uncut materials.

 

[RayIN]

Based on all the replies that I have gotten so far from everyone that took the time to comment, it sounds like the only way to solve this mystery is to get the opinion of an experienced operator or demo the product to be sure of what you need. Flail mowers are so niche that not many people have experience with them and when you add on top of that a model of flail mower that not anyone on TBN has, it just becomes practically impossible to make an educated guess. However, I do have a contact that I am in touch with that is very experienced with flail mowers and has actually been selling them for over 30 years. I sent him some pictures of my property early this morning and are waiting for a reply back from him. If and when I hear back from him I will be sure to let all of you know what he says.

You must weigh the stress on the tractor engine. I would not want the engine to be working at 100% capacity for an extended period of time. It greatly shortens the lifespan of the engine and drivetrain.
Usually as HP increases, so does tractor weight. Buying the smallest size tractor not only shortens its lifespan, but the lighter weight will result in several things, wheel spin is just one, this results in more fuel consumption, more drive tire wear, and more wear on the drivetrain.
I could go on, but by now you understand the point.
That 75% capacity for your total needs is a reasonable decision IMO. This leaves a 25% margin for those seldom heavier patches of brush or heavy, blown down Johnson grass one might encounter, without having "too much tractor" as you said.
An example I'm familiar with; a neighbor bought a John Deere CUT W/FEL and belly mower, and back hoe, about 28 HP. He has a depression he'd like to mow but says he's hesitant to drive down into the 1 acre depression for fear he cannot drive out when finished mowing.

He asked me if I'd mow it for him with my MF 451, 52HP tractor and rotary mower. I declined for insurance reasons.
Now had he bought a large enough tractor for his requirements, he'd not have any issues.