Flail Mower Boom Flail Questions...

[bjcsc]

Well I finally tried out my mower that I asked about previously in this thread. I had to replace one of the cylinder hoses, but all the other hoses, both pumps and the motor all work great. I had to make a few small parts (the chain bracket and pieces to mount the cable controls to my ROPS, etc.).

This mower (Bomford B457) reaches out 14' or so from its center. My tractor is pretty stable with it all the way out. I can tell it's out there, but I can also tell it is nowhere near pulling me over. Nonetheless, I have been wondering about ballast, and whether or not I should add something to the offside of the mower itself, load my tires, get used to it being out there or what. Most of the time the cutting head will be close to the ground (safe), but some cutting I intend to do is more similar to hedge cutting and the head will be 10' from the ground (less safe). I have a ballast box that has been more than adequate for everything I've done with my loader so far, but the manual says load the tires. I can pick up round bales with nothing behind me and not be light on my rear. I've read every thread about loading tires on this forum and I am undecided...

I also am not sure if I am supposed to drag the mower head on the ground (it has a roller), or suspend it in the air, or what? The first cylinder is connected to an accumulator. There is a delay when raising the mower. The manual said it allows the cutter to follow the ground (but I don't see how unless it will float up) and to allow most of the weight of the rotor unit to be carried by the tractor. This seems contradictory to me. I only cut about 30' or so and I was in super-cautious mode so I didn't really test it.

Maybe one of you guys have used one similar and can offer some advice...

 

[sandman2234]

From what I can tell, mine has a little more reach than yours. I do not have my tires filled, but it is running duals, so the weigth is approaching the same, but I have a wider footprint. (11' 3" outside to outside of rear wheels)My deck is 4', using the hammer blades. The front of the tractor has 12 weights on it, almost 1100 pounds plus the weight bar. I can extend the boom rearward and pick up the front axle (front wheel drive, also).
My mower isn't on the boom right now, as I built a 42" bucket to load a pile of dirt 3/10's mile up the road onto the dump trailer I recently built with a friends help. I needed some dirt, and my Church let me have the dirt, so I needed a way to load it after building a trailer to haul it on. I got unemployed unexpectedly, so I wasn't going to spend the money on renting a loader, so I figured I would make a lightweight backhoe out of it. Worked great!
There is no delay with mine when lifting, but it might be that mine is an older model, without all the neat updates? I run the roller on the ground when I can see what I am mowing and it looks ok. If there is water or obstacles, I try to keep it just a little higher than the roller.
One thing that you might consider is a solid piece of Lexan between you and the cutting head. I can turn my cutter head towards the tractor if I need to, and should a blade come loose, it could be lights out. Plus when you start mowing hedges, tree limbs and whole trees, there is a chance that some of it is going to come your way, and often with substanial force. Mine will cut either side, but the controls are on the left, so most cutting is done there. That is the side that the Lexan is mounted to the ROPS between the fender and the roof. It isn't mounted to the fender or roof, just between them mounted on a bracket bolted to the ROPS.
Hopefully you allowed enough room between the chains and the cutting blades, so they won't come in contact with each other in a worse case scenario.
I don't have a manual for mine, although the a guy at the shop of the company I bought it from says he may have it at home. They were throwing out all the old manuals, and he grabbed a few of the ones he thought he might need. Getting him to check to see if he has it is the problem.
I am sure you will gain confidence in the use of the mower. It really isn't hard, just requires a lot of attention, and good neck muscles. Stay on it all day and you will have a sore neck the next morning.
David from jax

 

[prosperity]

I've run boom arm mowers for years along the highways. We ran a rotary head though, not a flail head.

About balast - I don't know what your mower is set up like, but our mowers (Tiger) had the hydraulic tank on the left side of the tractor which helped with balast. In addition to that, we had 3-4 wheel weights on the left rear wheel. This setup made it very stable.

Before you go mowing with the head in the air, do a little test. In an open area, without the mower running, extend the arm all the way out, and lift it up so your boom is about horizontal. Then drop the boom about half way to the ground, then stop it. See how your tractor reacts. If your left rear wheel comes off the ground, you need some more balast. Yeah, you'll get the tractor rocking a bit when you do this, but your left rear wheel should pretty much stay in contact with the ground.

When you do get to mowing with the boom in the air, carefully watch the ground you are rolling on looking for dips and/or holes that your right wheel can get into. It's all about stability and keeping the tractor level.

Doing the test I metioned above also helps you get a good feel for the machine. There is some "pucker factor" when running a boom arm mower - get comfortable with how it feels. Always be ready to drop the mower head if you get the slightest feeling of tipping over.

And for carrying the head - always carry the mower head just above the ground. Never "drag" it on the ground. Dragging it will put a lot of stress on the boom arm joints. You will be constantly adjusting the lift control to make the head stay about 2" off the ground.

Go slow - at a pace where you are comfortably adjusting the mower head as you go.

 

[bjcsc]

Thanks for the replies. It does have the tank offset to the left (the arm stretches out to the right). It is set up exactly like a Tiger mower, even looks the same as if they used the same tank and parts. Prosperity: I did a test very similar to the one you mentioned, except I looped a sling around my ROPS and chained it to one of the poles on my barn on the left side (told you I was in super-cautious mode!) I stretched it all the way out, bounced it, dropped it like you said. I even went out to it and climbed on it to see if I could lift the rear left wheel: I couldn't. I thought about wheel weights, but the only ones available for my tractor are 95lbs, and a max of 2 can be added. That's pretty much useless. Did the tractors you used for highway mowing have loaded tires? I guess it will just take some getting used to...I am still wondering what the accumulator is supposed to be accomplishing...

David: Neck muscles!! Dang...that's why I got a loader. I got tired watching my 3pt. moving hay, using a boom, etc....

 

[prosperity]

No, our highway mowers did not have loaded tires.

Sounds like you are pretty stable with your testing.
We had one machine come in - a Case tractor with an Alamo mower. This was set up very poorly - all you had to do was extend the boom, and the left wheel was off the ground. I refused to take it out.


The accumulator -
What that does is this - when you are lower the main boom, there is of course no hydraulic power down. So, as you are lowering it, it is just the weight of the boom pushing the hydraulic fluid back to the tank. The fluid from the return of that cylinder travels through that accumulator on its way back to the tank. So as you are lowering, then you stop, the accumulator takes some of the shock out of that sudden stop of fluid. It is actually like a bladder tank that would be on a well water system.
Without the accumulator, the sudden stop of fluid would make the boom more "jerky" possibly causing your left wheel to come off the ground. With the accumulator, it makes for the boom to have a softer stop when you neutralize the lever.
You might have noticed when doing the test we talked about - when you stopped the boom on the way down, after stopping, it would continue to rock a little bit. This is in part the tires flexing, but mostly the accumulator doing its thing.

I am very happy to hear that you are being so cautious and testing things out the way you did. I was also involved with a lot of safety training with that job and it has all really stuck with me.
You should have seen me my first time on my zero-turn mower on hills - I was really cautious, gradually testing it out in different situations until I got more comfortable - ROPS up and seat belt on at all times!

 

[sandman2234]

My boom mower has power down as well as up. I know, as i just used it as a backhoe to load about 600 yards of dirt. I was warned never to run mine without duals, as I considered taking a set off to narrow the width. The operator that told me said mine gets real light without the extra width. My hydraulic tank is centered in the rear, and the arm will work from either side or behind the tractor. I have a rotary mower (5') that has never been run, but I like the flail head, so I haven't ever plumbed the hydraulic hoses to the rotary.
David from jax

 

[4x4sche]

The accumulator is there to allow the flail head to float along the ground. (I have a manual valve on my accumulator to "turn off" this effect and get a more direct response for cutting the tops of hedges etc.) For cutting on the ground, here is how you set the boom. Lower it fully to the ground and then raise it using the cylinder with the accumulator (usually the lowest boom cylinder) until the head is just lifting off the ground. The weight of the head is now fully supported by the gas "spring" in the accumulator. This will allow the ground contacting roller to raise the head over bumps with very little force as you drive forward. Without this accumulator the whole weight of the head is resting on the ground as soon as you move forwards and the ground raises by even an inch. With the accumulator you can allow the head to float along over 6-12" variations on its roller. Since the tractor wheels also go up and over bumps, I cannot imagine working without this. My driveway and pond edges are almost a mile, it would drive me crazy to continuously adjust the height with the controls as I drive.

 

[Grrrr]

I think everyone else has given you good intsructions on using your machine.

We mainly use them on hedges so have to constantly adjust them. They even have competitions around here to see who can make the straightest job on a hedge

The last time I used one the tractor had filled tires and ballast on the front. It didn't feel tippy but it did have 110 HP in the bonnet

 

[bjcsc]

but it did have 110 HP in the bonnet

Wow, that's a heavy hat

I spent a couple hours yesterday evening mowing. I didn't have any trouble feeling light and was quite used to it by the time I was finished. I still have much more to do and expect it to go as well. The mower did a great job. I would like to check the rotor shaft bearings, but don't know how it disassembles. I might try to get into it this evening...

 

[RAILTRAC]

Has anyone seen ?, or does anyone have a boom flail on a JD 3720 ? I asked this same question to most of the companies that make them and only Alamo
Industral had the courtesy to contact me, then there local dealer here contacted me.Asked a million questions. The reader digest version never heard of a JD 3720 had sold the 4720 with a boom mover, most common JD they sell with a boom mower is the JD 5525.