Flail Mower Let's talk flail mowers

[leonz]

Why are bolts bad? What types of failure could one expect to encounter with bolts vs welds?

Around where I live people have been driving over HUGE metal structures -bridges- that are essentially BOLTED together (rivets and or bolts). Should they panic because bolts and rivets are being used? Bridges can be subjected to immense stresses.

I would be more receptive to an argument that considers the roller or the drive mechanism, as these things, I'd think, take on more stresses.

I personally have no illusions that a flail mower can stand up to (or should be subjected to) the same sort of treatment that rotary cutters are subjected to.

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If you want to see stress on a flail shredder mower you should watch them work with a forestry flail mower or cutting sugar cane stubble on irrigated land, cotton stubble on irrigated land or pineapple brush stalks soon after harvest. Just like butchering hogs, its noisy and ugly until the dust settles and there is no brush or plant stubble left to be seen.

Flail shredders are stronger because the continuous weldments and four plate construction with rolled shroud weldment make the entire flail mower a one piece affair with 5 continuous welds on average.

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I never attacked them ever, As I have said in the past, the reason is that "a" bolted side plate being both the driven side and the carrier bearing side of a flail mower shroud will be subject to the same stresses that a welded side plate is subject to being-1. racking, 2. twisting of the shroud and side plates as the mower works as the rear roller is following the ground contour and pushing upward against the mounts for the rear roller putting stress on the flail mower and the weight of the flail mower is pushing down on the entire width of the mower to the rear roller.

There is a good reason Mott went to rear wheels with the ability for manual height adjustment for some of thier mowers in the beginning and Wessex uses them on the towed motorized flail mowers using twin cranks and worm shafts to set the mowing height for the front and rear of their motorized mowers as they do not have a rear roller.

The radial stresses coem from crossing over the ground where the Y axis is pushing from one or both sides of the X axis of the mower from the rear roller forward and upward across the side plates and flail mower shroud

With the Flail Mower Shroud welded to the side plates and then the front of the shroud and side plates welded to the tubular steel stock with continuous welds around the tube stock and across the front cross weldment plate and the weld continues with a continous weld from the front of the shroud weldment on both sides to the mounting point for the rear roller which has been the weakest part on some flail mowers. The fully welded body counteracts any wracking and twisting and any forces transmitted by the rear roller to the side plates through the rear roller hangers.

It is essentially a "unibody" flail mower made from very thick steel weldments to become one very large heavy weldment that aids in cancelling out stresses delivered by the weight of the flail mower which is transferred to and from the rear roller and or skid plates if an impact occurs.

 

[DieselBound]

Great, thanks, leonz, for providing some basis here!

Given that welds are superior, at least in the case of flail mowers, and that sidecarist has already noted that the Woodmax fails are welded, then that should be one less thing to be critical about with regards to the Woodmaxx, yes?

 

[sidecarist]

It's clear from the photos and videos on the website, that the woodmaxx fails are welded construction. The deck or shroud and end plates are 1/4in steel plate. The hitch assembly is bolted on not welded. This has both positives and negatives for me.

I can see that a casual look at the photos might give the impression that they are bolted together. The hardware visible in the photos is related to the rear trash door not the fabrication of the chassis.

I only point this out so that someone else doesn't get the wrong opinion about the construction. As I have said I'll gladly provide a review of the FM78H I have on order when it arrives. If anyone here wants specific photos etc I'll try and accommodate those requests.

I intend the mower for use on rough fields to shred/mow things like buckwheat, clover, etc. That we are planting for honey bee and wildlife forage. I will then re-seed those fields to rotate the crops. This will not be used to get a lawn type finish, but rather a better chop/mulch that a rotary would give. I'm not interested in speed, but because the volume of cut material will be high I want the option of opening the rear door.

Stay tuned...

 

[SI2305]

Dieselbound, sidecarist,

Thanks for your input. I have always found tractorbynet to be a wealth of useful, informed opinions and I certainly appreciate your inputs. Sidecarist, I have to especially thank you as you took the plunge for me. I am not in the position to make this grand transition right now, but in a year, perhaps. Sidecarists, please share pictures of your flail when you get it and tell us how well it works. I just got off my tractor and was flailing some trails I have near my house. Now that I own a flail mower, I never want to be without one!

SI2305

 

[sidecarist]

Will do. Many here at TBN have been helpful to me. I hope I can repay that helpfulness.

 

[leonz]

Yes it is a plus for them, the big worry is always a roller bearings quality of manufacture and their "B10 Life".

At least "all" bearings are metric just like V belts per international convention so that is one less thing to worry about in the scheme of things.

Whether they used the right high speed spherical bearings rated for 2,200 Plus RPM for the flail mower and whether it is sealed on one side to hold the grease in the open bearings housing is another concern-remember also that they are "three locked in place open bearings"- the cross shaft, the driven side and the carrier bearing side.

I have a 36 year old U joint coming from my engine to the first open drive bearing so that's a plus


The rear roller also travels at high speed on the ground, not 2,200 RPM but the rotation speed is faster than the front tires on the "mule" when working due to the smaller rolling radius of the flail mowers rear roller.

The rear roller bearing quality is just as important when examining these things as these bearings do a lot of work and react to the stresses from the flail mowers movement along the ground-one more reason for rear mounted wheels on unknown ground/ground not mowed in many years as the ant hills and brush clumps will do a number on thin rear roller tubes and when a roller gets wacked it pushes agains the inner race of each rear roller bearing and it will get messy just like losing a set of Brillion cultipackers when the 500 Lb. gang of packer wheels falls off due to the inner race of the one of that gangs bearings breaking away due to the bearing going bad from dirt and or lack of grease or stress from rolling over rocks that pop up after the ground was disc harrowed after plowing.

Ideally a rear rollers bearing sets should be a double row ball bearing but I do not think you will ever see that happening.

 

[Dan in MN]

A little update.. finished rebuilding the carb on my '53 Ford Jubilee today and it seems to run a bit better, but had same results trying to mow. I get a little ways in and then the mower just seems to load up and pull the tractor down. Had to think back to when I had some better success mowing originally and had a bit of an 'aha' moment... I posted some pictures of a certain type of stalk that was popping back up, and as I started making adjustments to get it to mow better I dropped the back of the mower closer to the roller to mow lower, and also raised the front at times to try to expose the flails to the material better. What I believe may be the issue now is that dropping the housing closer to the roller reduced the amount of space available to eject cut material, and it may be building up underneath as I try to mow areas with ~2 ft tall green grass. I have around 2-1/2" from roller to housing now, would be curious how much space some other flails have? Tomorrow I'll be dropping the roller all the way down away from the housing to get the max opening size for material ejection and trying again...

 

[CADplans]

A little update.. Tomorrow I'll be dropping the roller all the way down away from the housing to get the max opening size for material ejection and trying again...

That sounds like a good possibility,,, the vegetation has to go somewhere!! :thumbsup:

 

[Dan in MN]

That sounds like a good possibility,,, the vegetation has to go somewhere!! :thumbsup:

Shoulda bought a Woodmaxx with the peekaboo door in back.... :laughing:


With the way things have gone for me it probably won't make any difference, but it does make a lot of sense with the way the tractor feels like it's working really hard and then just gets dropped to it's knees..

 

[CADplans]

Shoulda bought a Woodmaxx with the peekaboo door in back.... :laughing:


With the way things have gone for me it probably won't make any difference, but it does make a lot of sense with the way the tractor feels like it's working really hard and then just gets dropped to it's knees..

As slow as you have traveled at times mowing,,,
the tractor should not even know the mower is doing anything,, once the rotor is turning.