Low HP flail mower

[SI2305]

Greg_g

When I was making the tire size comment, I was keying in on the HP comparisons to the yanmar which was stated to be 16 pto and yet ran a 5 footer. My assumption was that since the HP was being stated in PTO terms, we had a reasonably close apples to apples comparison. The tire size comment was a simple observation of physics: given a constant power source, it will be easier to turn the smaller tire than the larger tire. I have heard a few 2320 owners mention that they cannot mow in high gear. Under the hood, my understanding is that the 2305 and the 2320 are basically the same machine. I believe they have the same engine, same transmission, and one of their few differences is the rear tire size. Personally, I have had no difficulty mowing in high gear (provided the ground is smooth). Therefore, I assumed that given the similar PTO (actually slightly favoring mine) and my smaller tire size (easier to move the prime mover), I could handle the same load he did.

As far as ratings for HP, I don't doubt that these are stated in the most advantageous terms and I agree with you that JD as well as just about every other manufacturer will state the best rating with which they can get away. Or even bend the truth a little. Maybe break it once in a while. Just not too much as to thoroughly discredit in the future.

Ultimately, I was trying to make the statement that if I took it slow, I might just be able to make use of all 60 of those cutting inches and make handy use of an offset to mow some of the brush by my rather long hedgerow.

As for the PEC, I understand the physics of how moving my lifting point further from center lessens the lifting ability by increasing the mechanical load on the lower arms that are doing the work. However, I use the PEC with my nearly 600# RFM with ease. My LX4 is about 450# but sticks much further from the tractor link ends and therefore exerts even more mechanical load. The Befco 60" flail mower is rated at 450# and is not nearly as long as my LX4. I think I am in safe as far as any potential lifting goes. As far as balancing, I have the loader on which certainly adds plenty of weight, and I do have a piece of hickory trunk 2&1/2 feet long by 20 inches in diameter. It makes wonderful balast.

I will state clearly for all. I know that I have a small tractor, but I am patient with my activities and I am careful with things like mowing in tight areas or mowing dense material and as the tractor labors to chew up more material, I am not going to aimlessly continue at the same speed. Instead I would either slow down, or alter direction so that not all of the mower is engaged in cutting at the same time. I might even have to back up and try again.

Greg_g, this might sound like a vitriolic response, but it is not. I do want to be challenged before I buy so this is why I have asked the questions and given info. I appreciate your comments, especially the ones regarding the rated power and your actual experience with PTO activities. That certainly says something is amiss with the HP ratings. But the larger tire size and mowing difficulty is a comment I have heard from several 2320 owners. I assume their engine HP is needed more for simple motive power and leaving less for rear PTO power by comparison to mine which requires less motive power to move the smaller tire. Either way, the solution is to slow down.

I may have over-analyzed this particular response, but my thoughts are in print now so you can see how I arrived at my conclusions.

I look forward to your response.

SI2305

JD 2305
200CX, LX4, 60" Grader blade, 60" LandPride finish mower that replaced our old lawn mower, middlebuster, home made grass rake for long field grass collection, and now a specialized trailer to move heavy logs

 

[greg_g]

Guess we don't share a common definition of vitriolic either. I thought that was a quite reasonable response. But I do think that business with tire size is a red herring. Tire diameter does in fact impact ground speed, but that should be the only effect on PTO operation. PTO operation itself is a function of engine RPMs - typically 540. PTO revs are usually determined by watching the tachometer and setting the hand throttle. From there, the operating efficiency of PTO implements like mowers is subsequently affected by ground speed. Go too fast, your cut suffers. Go too slow, you waste time and fuel.

Dig into your 2305 operator manual Specifications section. You should find a set of tables listing ground speed versus tire diameter. Pretty sure that should fix the over-analyzing problem.

//greg//

 

[SI2305]

Greg_g

It seems that we are going to have to disagree to agree. Yes, I do mean what I said and in that order. Since we are talking about an activity that involves both PTO operation (flail) and a prime mover (tractor going forward), then the easier the machine can go forward, the less power it robs from the PTO. In this case, smaller tires are easier to move and since the engine will be taxed to at or near its max, then the smaller tires are an asset.

If we were talking about a PTO intensive operation that did not involve movement, then tire size is irrelevant. PTO chipper/shredder would be a perfect example. In this case, the only relevant power is that coming out of the rear PTO.

However, since nearly every type of mowing at some time taxes the forward velocity of the tractor (bush hogging, finish mowing, and of course, flail mowing), at some point there needs to be a compromise. Usually this means just slowing down a bit. However, those larger tires are going to be tougher to turn than the smaller tires so when the heavy mowing hits, all things being equal, it will be the larger tire that slow down first.

All things are not equal and I was trying to make the balance sheet

Yanmar*******************2305
Gear*********************Hydro
Large tire*****************smaller tire
16 PTO*******************18 PTO (maybe)


They may not be equal, but they seem pretty well matched. I do think that the tire size, despite the length of our discussions, is the least relevant part of the equation. However, it might just help make up for that power loss associated with hydro's. Basically I hoped to mow at my usual speed which is in low gear and take it easy by the hedgerows. I don't see how I am going to get these with a 48", so my hope was that a 60" offset would clean those rows along with the trails that go along with them rather nicely.

So, despite my logic, rational, or reasoning, do you hazard a guess as to my being able to nimbly but carefully (no speed records) being able to operate a 60" offset flail mower, possibly from BEFCO?

SI2305

 

[greg_g]

In the olden days of the transmission PTO, you would be not far off the mark. But most tractors manufactured in the last 40 or more years have either live or independent PTOs. Here's an excerpt from TractorData.com:

Transmission

The simpliest, and earliest, form of PTO is the transmission PTO. The PTO shaft is directly connected to the tractor's transmission. The PTO is only working when the tractor's clutch is relased, so if you take the tractor out of gear while slowing down the PTO will stop working. This is a disadvantage in applications such as mowing.

An overrunning clutch is often needed with a transmission PTO. Without it, the driven equipment (such as mower blades) will put a force on the PTO shaft, and then the transmssion, due to inertia. The equipment will "drive" the tractor, and you will still move after using the tractor's transmission clutch. An overrunning clutch prevents this from happening by allowing the PTO shaft to freely spin in one direction. In more recent models, this is built into the tractor. In older tractors, it is an extra piece of equipment mounted on the PTO shaft.
​

Live (two-stage clutch)

A live PTO works with the use of a two-stage clutch. Pressing the clutch half-way will disengage the transmission while pressing it fully will disengage the transmission and the PTO. This allows the operator to slow down or change gears while the PTO is still operating.
​

Independent
An independent PTO means that the PTO shaft is controlled with a separate clutch. As with a live PTO, this allows for full control over the tractor while separately controlling the PTO. There are two major types of independent PTO; mechanical and hydraulic. A mechanical-independent PTO uses a separate on-off selector, in addition to the PTO control lever. Often the tractor must be stopped or off to change this selector position. A hydraulic-independent PTO uses a single selector.

And my previous suggestion remains germane; find a rental outfit (or a neighbor) that has a 5 footer, try before you buy.

//greg//

 

[SI2305]

Greg_g

Actually, those terms/definitions are quite useful as I never exactly understood what a "Live, overrunning clutch was". I have still heard of 2320 owners complain of not being able to mow in high gear or have their tractors struggle to go up hill in high while mine has never hesitated. In fact, it does not hesitate to do much of anything that I throw at it. Mind you, I really am not trying to find its limits for obvious financial reasons, but I attributed this phenomena to tire size.

I agree with a "try before you buy." Unfortunately I don't have that option, so my second best option is to hash it out here. My gut tells me I could probably handle the 60 inch if I were careful with it, I have seen enough video's to see it happen.

I am sure we will talk later,

SI 2305

 

[greg_g]

Comparing the 2305 to the 2320 is another case of apples and oranges.
The basic 2305 is a 1450 pound SCUT rated at 24.1 engine hp and 41.7 ft-lbs of torque.
The basic 2320 is a 1660 pound CUT rated at 24.0 engine hp and 40.27 ft-lbs of torque.
The performance difference is a matter of power to weight ratio, tire diameter doesn't enter the picture.

//greg//

 

[SI2305]

Greg_g

I think the particulars on the specs you showed to me are an example of what you stated earlier as Deere (and others) being choosy about just how they represent their engine stats. In your figures, the difference between the two machines is less than 1 HP and barely 1 ft/Lb of torque. I believe they use the same engine and tranny. The 200# difference is the only spec that is measurably different in a practical sense, but as this is still only %15 their gross weight I still don't think this is going to count for much, especially as one starts adding more weight to the machines in the form of loaders, mowers (of all types) and or course the operator himself. Add these together and that percentage marginal difference in weight gets even smaller. I do believe that tire diameter, perhaps the only significant factor left, will make a difference.

Take a hypothetical. If I were to add the tire of say a 4720 to my little tractor and assuming zero losses for the obviously complicated hardware, would I even be able to move my tractor now over a level parking lot? Probably, but it would not take much mechanical load anywhere on the system to bring this weird hybrid to a halt.

Take bicycles. As we get larger bikes for our growing kids, they always want the larger one until they realize that they have a much harder time pedaling than on the smaller one. The gear ratios are the same, it is just much harder for their little legs to move that larger diameter tire. Eventually, they will catch up to the physics and want a new bike and we move on (hopefully to a hand-me-down).

The same physics applies to tractors too, and I think that given the specs you mentioned to make the 2305 and the 2320 apples and oranges, I think they are really apples and apples in most situations.

We'll chat more

SI2305

 

[SI2305]

Knotweed,

This would be a great time for those pictures of your yanmar/flail operating. They have started a rather good debate and while they won't settle anything, I am itching to see what your 16 pto ponies can do with a 5' flail mower.

Hope to see your picts soon,

SI2305

JD 2305
200CX, LX4, 60" Grader blade, 60" LandPride finish mower that replaced our old lawn mower, middlebuster, home made grass rake for long field grass collection, and now a specialized trailer to move heavy logs

 

[IslandTractor]

200lbs of tractor weight doesn't seem very significant to me. A Kioti CK20 with 22hp weighs 2150lbs and would be just as effective. Yeah, when going up hills in high range tractor weight counts a bit but at mowing speeds in low or medium range it really is not a major factor in what horsepower remains to drive the PTO implement.

I would also agree that tire size is almost irrelevant as again the amount of horsepower needed to actually move the tractor itself is pretty small. If HP used in actual locomotion is maybe about 4-5hp and smaller tires give you 15-20% extra torque, that benefit amounts to less than a single hp.

To me the choice between 48 and 60 in this case is driven by the need to cut next to hedgerows. 60" works, 48 doesn't unless you spend a lot of time and effort offsetting the mower. The total acreage of grass that can be cut in a given time should be about the same in lush grass or brush as you could go faster with the 48 but you'd cut more each pass with the 60. In lighter grass the 60 would cut faster as PTO hp would not be a limiting factor.

 

[SI2305]

Island Tractor,

You are a voice of moderation in a heated but friendly discussion. It seems that initial points made by both sides have been blown out of proportion. I am curious as to your opinion. Knotweed runs his 5'flail/16PTO Yanmar. I thought that would be as good a comparison as any I have yet seen on this particular thread. My initial comment about the tire side was that it would partly offset HP losses from the hydro. I did not intend for this to become the focal point of discussion.

So what do you think? For comparison sake in a scenario where we can likely never get identical equipment to do side-by-side testing, does the following sound like reasonably close apples-to-apples comparison:

Yanmar*******************2305
Gear*********************Hydro (a minus)
Large tire*****************smaller tire (maybe nothing, maybe slight plus)
16 PTO*******************18 PTO (maybe) (small plus)
runs 5'Flail*****************don't know(?)
(Overall close to equal?)

Again, I highly doubt I will find someone with exactly my setup, but this seemed like a reasonably logical comparison--do you agree or am I misjudging? Thanks for your input. It is well placed and seems well reasoned

SI2305

JD 2305
200CX, LX4, 60" Grader blade, 60" LandPride finish mower that replaced our old lawn mower, middlebuster, home made grass rake for long field grass collection, and now a specialized trailer to move heavy logs