Flail Mower Let's talk flail mowers

[Weedaway]

Another option for you to examine is to simply remove two rows of knives as long as they are opposite of each other and continue mowing that way with less work and chaff.

My Caroni has the finishing rotor, with twice as many blades. I just left off every second pair on each row. It works great and there are no gaps on the cut. This rotor uses a spiral design, so YMMV.

 

[ddbackhoe]

Being on the front of the Steiner the maneuverability is fantastic and i can mow very extreme bank sides now which is what i wanted when i started this project. There is a few cons, one being that with the mower mounted in front the radiator gets plugged with in 30 minutes of mower and the tractor starts to get hot.

I am pretty jealous right now. That video makes it look like a great match. I am curious about two things. Why do the clippings plug the intake screen(s)? Why did you opt not to use the front gauge wheels?

With a good lathe, I don't see any reason why you couldn't fab up a new rotor out of a piece of schedule 80 pipe

 

[Fallon]

I am pretty jealous right now. That video makes it look like a great match. I am curious about two things. Why do the clippings plug the intake screen(s)? Why did you opt not to use the front gauge wheels?

With a good lathe, I don't see any reason why you couldn't fab up a new rotor out of a piece of schedule 80 pipe

If the mowing & dust raising is going on in front of your machine instead of behind you drive into the dust cloud. Clippings usually get caught by screens, but dust & other small chaff can be worse. My tractor gets the radiator plugged enough with the flail behind the machine. Earlier this week I found the radiator, A/C coils & granny cooler mostly plugged with small junk that made it past the vents on the hood as well as the screens over 2 of the 3 cores under the hood.

Round & balanced are 2 different things. Varying well thickness & density makes balanced hard. The faster things spin the more important balance becomes. It's relevant at 540rpm, but the impeller on a snow blower with use stuck to one side doesnt vibrate to bad. A rotor in a flail spins at 2,000RPM or higher. The length & speed make bearing & machine killing vibration much more of an issue.

You need a pretty long lathe to machine a 5-7' rotor. Not to mention it being decently in tolerance with a skilled operator. I just dropped $8k on s 13x46 lathe. Neither it nor myself would be up to the task (I'd be lucky to be able to machine a 9" diameter rotor 3' long. My brother has a lathe that might have been able to do it 30-40 years ago. It probably weighs 2 tons (double what my 40hp machine could lift) & was worn out decades ago (he mostly uses it for hand turning wood now).

Front casters would probably help keep things level & even. My Peruzzo would have them if I'd gotten a front mount model instead of a 3pt one (same machine, just different mounting gear).

 

[KTA CAT KILLER]

Correct on the clippings plugging the rad. the way that Steiner sucks in their cooling air and the way i travel into the dust cloud and not away from it causes the rad. to plug faster than a rear mount would. I assume that the rad never plugs with the finish mower is because it has side discharge. im also taking down some pretty thick stuff. when i moved to some thinner stuff i was able to go a lot longer with out cleaning the rad.

Im not using the front gauge wheels right now because the mower didnt come with them, it would be easy enough to build them and i think i will but i wanted to make sure everything else worked first.
2
the biggest obstacle was changing the rotation of the gear box to work with the rotation of Steiners belt drive. most gear boxes have a key way in both spots to put the pinion gear on the other side of the other pinion gear but this one did not. Fortunately we have a lathe and mill on our farm so i was able to make a new shaft with a key way on the correct end.

on the rotor balancing you are correct that it is beneficial to dynamically balance a rotor but that doesnt mean that is the only way to balance a rotor. 100 years ago there were combines with much bigger and faster spinning rotors and chopper cutting drums before there was electrical dynamic balancing. That being said i would love to not have to build a new rotor and i think ill take half the knifes off and try it.

The whole setup now has about 10 hours on it with the only problem being the gear box got major end play at hour 2 from me not having a snap ring in right. I was not able to find how fast Jacobsen turns this flail so i guessed and im running it at 2500 RPM rotor speed. At that speed it cuts good, there is no vibration, And after hours of running the bearings are cool to the touch and the gear box never gets over 160*F.

 

[aczlan]

Round & balanced are 2 different things. Varying well thickness & density makes balanced hard. The faster things spin the more important balance becomes. It's relevant at 540rpm, but the impeller on a snow blower with use stuck to one side doesnt vibrate to bad. A rotor in a flail spins at 2,000RPM or higher. The length & speed make bearing & machine killing vibration much more of an issue.
You need a pretty long lathe to machine a 5-7' rotor. Not to mention it being decently in tolerance with a skilled operator. I just dropped $8k on s 13x46 lathe. Neither it nor myself would be up to the task (I'd be lucky to be able to machine a 9" diameter rotor 3' long.

How about a semi truck driveshaft balancing shop? They are used to handling and balancing stuff that long.

Aaron Z

 

[Fallon]

How about a semi truck driveshaft balancing shop? They are used to handling and balancing stuff that long.

Aaron Z

It can definitely be done & a driveline shop would be a good candidate for doing it. But getting end cap's on & properly centered then balanced can be a challenge unless you have the right lathe & jigs. Welding on a a bar or tabs to mount knives or hammers on messes with the rotor staying straight & balanced even more. It's all doable if you have the equipment, but there is a reason a replacement rotor costs half what the whole consumer grade flail costs. I've heard some people try to get driveline shops to balance rotors, but they wouldn't take the work due to liability & insurance reasons.

Fabbing up a rear roller is a lot easier as it's spinning much slower so doesn't have to be perfectly true or balanced like a rotor.

 

[ddbackhoe]

Round & balanced are 2 different things. Varying well thickness & density makes balanced hard. The faster things spin the more important balance becomes. It's relevant at 540rpm, but the impeller on a snow blower with use stuck to one side doesnt vibrate to bad. A rotor in a flail spins at 2,000RPM or higher. The length & speed make bearing & machine killing vibration much more of an issue.

Where did I say anything different? I do have access to the right equipment, but building a rotor is something I have not had a need to do....yet. I didn’t say it was easy, but it is doable. You could build a jig with some scrap metal, bearings and an electric motor if you really wanted to.

 

[aczlan]

It can definitely be done & a driveline shop would be a good candidate for doing it. But getting end cap's on & properly centered then balanced can be a challenge unless you have the right lathe & jigs. Welding on a a bar or tabs to mount knives or hammers on messes with the rotor staying straight & balanced even more. It's all doable if you have the equipment, but there is a reason a replacement rotor costs half what the whole consumer grade flail costs. I've heard some people try to get driveline shops to balance rotors, but they wouldn't take the work due to liability & insurance reasons.

Fabbing up a rear roller is a lot easier as it's spinning much slower so doesn't have to be perfectly true or balanced like a rotor.

Here is a thread where someone made their own: http://www.tractorbynet.com/forums/build-yourself/220394-my-homemade-flail-mower.html

Some videos of someone's project:

Rotor to homemade heavy duty flail mower Part 2/3 - YouTube
Rotor to homemade heavy duty flail mower Part 3/3 - YouTube

Aaron Z

 

[def38]

Today I went back to the dealer and put a deposit on a Kubota B2650, then came home and ordered a 5 Caroni from Agri Supply. Tractor is supposed to arrive on Tuesday, and the Caroni is scheduled to ship the same day, so I should see it either Wednesday or Thursday. The Caroni could have come earlier, but I need the tractor to move it down the driveway. (WoodMaxx is quoting mid-Sept for delivery of their 5')

So I need both gear oil and grease gun + grease before I can use the Caroni. Anyone have suggestions on brands? Some grease guns have a rigid tube, others a flexible one. I assume flexible is preferred. Is it better to get synthetic grease?

Jerik, The Walmart lubricants are quality products. I use their oils and grease with success. For your gearboxes, use Supertech gear oil, GL-5 rated, probably 80w-90 or 75w-140. Synthetic is not needed.

For grease, I use Supertech NLGI II, Lithium soaped and fortified with moly. It stays in place and provides EP protection.

What about the tractor engine? I use Mobil Delvac 1300 15w-40 HDEO in my Cat powered motorhome as well as the Perkins diesel in the Massey Ferguson. Synthetic not needed.

 

[DieselBound]

I wonder whether there isn't a bit of trade-off in radiator clogging with a front-mower. That is, IF the grass is really tall I tend to find that my radiator et al really tends to clog up; if the grass were cut down ahead of the front of tractor then the seeds/chaff(?) wouldn't be there to hit the front of the tractor: doesn't, of course, resolve the issues of cut grass being thrown back against the front of the tractor (I have no experience with this so I cannot qualify it).

I don't know about the Supertech greases, but I was recently researching oils and ran across testing data of their oils and was pretty impressed. A fantastic resource for oils/lubricants(?) data is: The Petroleum Quality Institute of America