Flail Mower Let's talk flail mowers

[leonz]

Greetings all -- First time poster here, and first time flail mower owner. I am looking for some advice on basic setup and mowing technique. I have a Kubota L4060 and Vrisimo Minimax 60" flail mower. I am looking to mow 10 acres of dense 3ft grass with some light brush mixed in on occasion.

On my initial mowing attempts, I quickly caused the main belt to smoke. My speed was between 1-2 km/h. Grass as mentioned above and moderately wet. I am thinking that the ways to manage this are, cut height and tractor speed. I was mowing in a snaking line, taking full width passes.

Given my circumstances what is the desired cut height? My intuition is that a higher cut height would cause less stress on the mower; and that driving slower would provide less stress on the mower. Yet, I have read here and elsewhere that having a 2" or lower cut height can be optimal given how these mowers operate.

Regarding cut height: I have read the owner's manual, and it seems to me that there are three points of adjustment. 1) roller height adjustment ie, "back gauge roll adjustment", 2) top link arm length adjustment, 3) actually raising or lowering the three point hitch. Is this correct? It seems to me that the top link arm length adjustment makes that roller a pivot point causing the mower to sit at a shallow angle.

In general is it best to mow in rows or spirals? Should I take full or half passes? Should I make multiple passes?

I will continue to read this thread looking for answers, but thought I would post here as well.

Much obliged to any advice.

Good morning cptmax,

I want to welcome you as the newest resident member of the "Flail Mower Nations" from Humboldt County in the Great State of California.

As you are a first time flail mower owner you have a small learning curve to deal with and "once you go flail you never go back".

Thank you for supporting the economy of The State of California and purchasing a Vrisimo Flail Mower.

OK, lets get your flail mower set up first:

But before that you need a physics lesson to help you understand how your flail mower works and why it does what it does.

Your beautiful American made flail mower operates using the verticut method of mowing.

The flail mower/crop shredder creates a pressure gradient(vacuum) under the flail mower rotor shroud to lift and cut the clippings/brush/crop residue up and over the flail mower rotor and throws it back down on the ground.

The 33 knife hanger mounting positions are staggered to allow the side slicer or hammer knives to overlap when mowing assuring that all the side slice knives cut the entire 60 inch width of the flail mower.

The Flail Mower Rotor to which the hammer, double edge side slicer or dethatching knives are attached spins at 2,200+- RPM when your mules 540 RPM PTO engine speed is reached using a one to one gear box with the cross shaft connected to the drive pulley which uses a V belt to spin the driven pulley to spin the Flail Mower Rotor at 2,200 RPM+-.

Vrisimo and others refer to their flail mower rotor as a cutter drum which is technically wrong but not an issue.

The ideal cutting height is 2 inches, this allows the flail mower to create the pressure gradient to mow the brush and lift the clippings up and over the flail mower rotor.

NOW, please listen to me as I show you how I want you to set up your mower for trouble free mowing.

Setting up your flail mower requires a flat level surface, as you are a first time user of a flail mower this is very important.


Your Vrisimo Minimax Flail mower has three rear roller adjustments which regulate the mowing height of the knives in combination with the top link adjustment, this is the adjustment you need to make for your mowing needs.

The lowest mounting position creates the highest knife cutting height which is 3 1/2 inches which is where you should start as a new user. You should make this adjustment first by lowering the rear roller to the lowest mounting position.

First you should support the flail mower with a wide wooden plank resting on concrete blocks before you do this. After this is done I want you to lower the mower to the flat surface and leave it there.

The skids are never to touch the ground, they are there to protect the cutter drum/flail mower rotor from impacting a mound from ants or gophers etc.



Please use blue loctite on the roller mounting bolts to hold them in place and to prevent them from loosening.



Now, after you have lowered the rear roller to its lowest mounting position I want you to use the bubble level in this manner; place the bubble level on the gear box facing you as you work from the left or right side of the mower and slowly rotate the top link adjustment watching the bubble level until the bubble is centered and then stop and lock the top link in place. This is your forever adjustment on your flail mower to maintain level plane from front to back.

I have to go and do chores and I will be back to help you more with this, so hold on until then please.



Leon

 

[leonz]

Now back to you mowing needs,

When a flail mower is running well and clipping brush and grass it will sound like a big shop vac,
this is how you can tell it is running correctly.

No more than 5 or 6 pumps of grease in the rotor/drum bearings every time you mow.
No more than 4 pumps of grease in the rear roller bearings or the V belt idler bearing.

You should invest in a Gates V belt tension gauge so you can properly tension the V belts on
the Minimax flail mower when needed.

With your L4060 you need to make sure the lower links are tight to keep the mower centered.

Which Kubota L4060 model do you have, the DT, GST, HST or HSTC?

if you have an all weather cab the mowing will not be so tedious and hot and you can listen to a radio if it has one.

If you have a ROPS you can always mount a fender radio on the tractor.

Did your Kubota dealer mount the Vrisimo Minimax mower for you or did you mount it on the L4060?

In making your first mowing pass it is best to start in the center of the plot and begin mowing in a tight circle at a crawl.

By doing this you create a center open space to work from. Don't worry about the un mowed center.

Now you can set your speed control to creep speed if you have it and start mowing.

Once you have made 1 complete circle you can move over three feet to take half cuts in a spiral pattern to mow the entire plot. Mowing in a circle save fuel and your brakes and eliminates backing and turning around.

Mowing will take a while but once you have it knocked down you can go over it a second time with you cruise control set a bit higher to recut the brush.

More on your tractor later.

 

[cptmax]

@leonz Thank you for your thoughtful reply and advice.

I will setup the cut height as you advised. The trickiest but will be finding a true flat spot as I live on a hillside!

I have the HST model, with a ROPS. I was thinking of putting on some music while I mow, but I wanted to better understand the belt burning issues first; the first indication of slippage is sound so I didnt want to obscure the warning signals.

The dealer did not mount the mower, I did. They did mention that I may have to cut down the PTO shaft length, but it does not seem too long to me, and installed without incident. I have eliminated the sway using the turnbuckles, and have it fairly centered.

The unit shipped with scoop knives. Given that I have light brush intermixed with the grass should I consider the industrial or dethatcher knives?

What causes the vbelt to burn and smoke? How do I prevent this?

How do I know when the belt need to be replaced? Are replacements available from 3rd parties or must I order from dealer or manufacturer? I will purchase a gauge as advised; how do I know what the optimal tension is?

Should I grease the rear roller bearings or the V belt idler bearing after every use?

I have noticed that grass gets wound up on the roller where it mounts to the frame of the mower on both sides. The grass is packed tight enough where I need pliers to extract. Is this something I should keep after?

Thanks again.

Max

 

[JethroB]

My first rookie flail (Caroni 72” on a Kubota 54 hp) mistake was over-greasing the bearings on the belt pulleys. Gooey mess very quickly when the belts melted. I follow the owners manual for greasing intervals.

Keep the blades out of the dirt, heavy wet grass, or standing water. My Y blades give a poor cut in wet grass or tight turns.

 

[leonz]

@leonz Thank you for your thoughtful reply and advice.

I will setup the cut height as you advised. The trickiest but will be finding a true flat spot as I live on a hillside!

I have the HST model, with a ROPS. I was thinking of putting on some music while I mow, but I wanted to better understand the belt burning issues first; the first indication of slippage is sound so I didn't want to obscure the warning signals.

The dealer did not mount the mower, I did. They did mention that I may have to cut down the PTO shaft length, but it does not seem too long to me, and installed without incident. I have eliminated the sway using the turnbuckles and have it fairly centered.

The unit shipped with scoop knives. Given that I have light brush intermixed with the grass should I consider the industrial or dethatcher knives?

What causes the v-belt to burn and smoke? How do I prevent this?

How do I know when the belt needs to be replaced? Are replacements available from 3rd parties or must I order from dealer or manufacturer? I will purchase a gauge as advised; how do I know what the optimal tension is?

Should I grease the rear roller bearings or the V belt idler bearing after every use?

I have noticed that grass gets wound up on the roller where it mounts to the frame of the mower on both sides. The grass is packed tight enough where I need pliers to extract. Is this something I should keep after?

Thanks again.

Max

Hello Max,

Do you use ear muffs or disposable ear plugs? Gemplers has ear muffs with AM-FM radio.

The burning belt issue is strictly do to extremely heavy brush and too fast a ground speed.

The scoop hammer knives cannot cut and recut the brush as quickly as the side slicer knives and the long brush that was sheared by the hammer knives is sticking and rolling around the rear roller. With side slicer knives you can mow backwards in thick brush and then mow forwards to knock it down more.

After you have everything knocked down after the first couple of mowings after readjusting the rear roller to the lowest position look at the sod and decide if you are happy with the amount of brush clippings. You will know if there is a heavy heavy brush load by walking on it or digging down to the bare ground with your fingers.
Remember that excess grass clippings/mowed brush can burn too.

A V belt has gone bad if it smells burned and the V belt has a glazed look and or the V belt has cracks or the rubber crumbles off in your hands.
Over time you will have rubber dust inside the V belt guard so that is not a real concern but checking the V belts once a month for wear and tension is a good idea.

Buying V belts is a personal choice, whether you by them from Vrisimo or the local farm store-read below-
You need to make sure that you have two "B42" V belts with identical lot numbers with Kevlar webbing which is more resistant to shock loading. My own preference is for either Goodyear or Gates Rubber Company V belts.

You have no way of knowing who Tractor Supply, NAPA, Farm and Fleet or Menards buys thier V belts from or whether they know that V belt pulleys with 2 or more grooves MUST have V belts with the same lot numbers as a V belt with a different lot number will stretch more under load.

I went through this with NAPA trying to buy snowblower belts for my JD snow blower that was equipped with metric v belts and pulleys, I am glad that thing went to the scrapper.

I have a motorized Mathews Company lawn Genie Pick Up Mower for my use and my father had a 7 foot JD 25A finish mower for his 12 acres of pasture.

When I use my flail mower I grease it after I mow and in so doing I remove the V belt guard and check the V belt and grease the flail mower rotor roller bearing on that side more easily. I have a spring tensioned idler pulley on my flail mower.

YOU MUST buy V belts in pairs; The 2 V belts MUST have the same lot number which is the number that is melted in the rubber carcass. If you decide to have spare V belts on hand put them in a black garbage bag, seal it and place the bag away from sunlight.


Please be very careful when raising the flail mower as raising it too high can cause the PTO shaft to break and in the process break the reduction gear drive from the transmission to the power take off and it will get uglier and more expensive from there if that happens.

You should not need to raise it more than a foot off the ground to transport it anyway.




Sent you a PM

 

[cptmax]

@leonz Thanks for the info on the belts. Will do.

I am currently in the process of adjusting the roller height; from the factory it came in the lowest position where both bolts can be attached (2 bolts per side lock the roller in place). I can pivot the roller lower and use only the lowest hole in the frame, but this would only allow for one bolt per side. Is this what we mean as the lowest setting? Or is the factory position, with two bolts, the lowest setting?

Photo shows the roller dropped to lowest point with one bolt.

 

[LouNY]

Yep, that is the lowest roller position which will yield the tallest cut. With the top link lengthen out to set the machine fairly level fore and aft. You can then vary the cutting height by lengthening the top link (taller stubble) or shortening a bit (shorter stubble).

When replacing multiple V belts as leonz has mentioned you should get matched bet sets or if your pulleys can fit them banded belts will work better.

They are available in most sizes and configurations, 2,3,4,or 5 belts in one

 

[dieselscout80]

Yep, that is the lowest roller position which will yield the tallest cut. With the top link lengthen out to set the machine fairly level fore and aft. You can then vary the cutting height by lengthening the top link (taller stubble) or shortening a bit (shorter stubble).

When replacing multiple V belts as leonz has mentioned you should get matched bet sets or if your pulleys can fit them banded belts will work better.
View attachment 880097
They are available in most sizes and configurations, 2,3,4,or 5 belts in one

The Ford 917 calls for a banded belt and it works good as well as last for a long time.

 

[JethroB]

A couple of questions about belts on my Caroni TM1900 72” flail:

What should the belt tension be? I am looking at buying the Gates tension gauge but the Caroni’s manual doesn’t specify.

Where do you shop for same lot or ‘matched’ belts?

Thanks

 

[Macinnis]

I have a flail mower question, but first the details.

I have had a woodmaxx flail mower for about 4 years now and it has been great. About 2 years ago, the roller came off and I got it repaired, no big deal. A month ago it came off again, but this time I know what I did to cause it, so lesson learned.

I repair it again. This time it came off 1.5 days later. I couldn’t wait, so I just cut without the roller on and it cut fine.

I have a hydraulic top link on my tractor.

Do I even need to use the roller?