Rotary cutter for M7040?

[canoetrpr]

If you have the time, then have at it. I had been under the impression that you had better things to do, not sure why I thought that, but I did. :confused2:

Thats probably because you thought I was a sane human being

 

[Chilly807]

Chilly807 - I don't think I follow your logic. That rule of thumb as I understood it is meant to provide guidance for minimum horsepower.

That's what I'm getting at.. if you have 62 HP at the PTO you are capable of running a 12 foot cutter under most normal conditions.

In addition if I am running the engine at the appropriate RPMs to achieve PTO speed I can't see how the engine is not being worked appropriately?

Diesel engines should be loaded to at least 75% of their capacity as much as possible. Few of us actually achieve that, but the engine will stay much cleaner internally and be more efficient. Low load equals low exhaust gas temperature, incomplete combustion, carbon and soot build up, and wet exhaust. Extended use (such as mowing) is an ideal opportunity to let the engine actually work under load for a while and clean itself out.

In general is there really something wrong with me running the engine at say 1500 RPM when transporting a load in the bucket?

RPM is entirely independent of load, so how fast the engine is running really isn't a factor in this case. Mine gets used at low loads more than I'd like. In your example it won't hurt anything, but you wouldn't want to run it like that all day either.

Hopefully this makes sense, I work on diesels for a living and it comes as second nature to me.

Sean

 

[Verticaltrx]

Having read what you posted right before I did, I think a 6' unit would work fine. When you move up in acreage someday you could keep the smaller one for ditches etc, and get a larger pull-type.

 

[5030]

The usual rule of thumb is 5 hp per foot of cutter, I'd be looking for at least an 8 foot cutter if not a 10 or 12. I'd say he has an 1872 in stock but nothing bigger?

The 1872 is a nice cutter, I have the 1860 for my L3400.

Something else to consider, if you're mowing any amount of ground. The engine will work better if it's loaded to at least 75% capacity most of the time. Low load for extended periods will result in carbon buildup and possibly glazed cylinders. The 6 foot cutter can't put much load on the 7040 under normal conditions like you describe.

Sean

I don't understand that. My M9 and 105 are never loaded at 75% of their rated PTO power and both have hundreds of hours with zero problems.

Could you be referring to extended idling time perhapse?

 

[gwdixon]

Just to chime in FWIW - I have a LandPride RCR2596 cutter (8') that mows 4' high old growth weeds down to 4" on a M7040 without the slightest lugging of the engine.

Mowed on 3rd gear low, 2400 rpm, to make sure nothing was missed. The tractor could have handled a much wider swath.

 

[Chilly807]

Just to chime in FWIW - I have a LandPride RCR2596 cutter (8') that mows 4' high old growth weeds down to 4" on a M7040 without the slightest lugging of the engine.

Mowed on 3rd gear low, 2400 rpm, to make sure nothing was missed. The tractor could have handled a much wider swath.

This is the point I'm making... a 7040 with a 6 foot cutter is like trolling with a 200HP outboard. You can do it, but why would you? The L3400 you have now with a six foot cutter would be a good match for the mowing you have described.

Sean

 

[canoetrpr]

This is the point I'm making... a 7040 with a 6 foot cutter is like trolling with a 200HP outboard. You can do it, but why would you? The L3400 you have now with a six foot cutter would be a good match for the mowing you have described.
Sean

I'm interested in understanding what you are specifically recommending though.

Assume I get a M7040 for reasons OTHER than specifically running a large rotary cutter though 4" saplings. e.g. having a nice big loader for round bales, a tractor that I can grow with, and the fact that it is pricing out to about the same as a L4740 / L5740.

With 8 to 10 acres of pasture I certainly don't need a 10' rotary cutter. It would also be a detriment for a ditch that I currently mow - just would not be able to do it with even an 8 footer. An 8 or 10 footer is also going to cost me a lot more.

In your earlier post you pointed out the possibility of damage to the engine over the longer term if I mowed with a 6' setup. Is this really the case or am I misunderstanding you?

I am moving up tractors for a cab and a larger loader for round bales. My L3400 is plenty for mowing which I do with a 5' rotary cutter. I'm trying to understand whether there is any real truth to a downside of me not working the tractor 'hard enough' which will affect longevity of the engine. I understand that I will burn more fuel needlessly if I pull the same size rotary cutter that I could pull with a GL4740.

One way or the other, an M7040 is going to be used quite lightly on my current property - compared to how it might be used on a much larger property. Is this a reason not to get it and get a smaller tractor at the same price?

 

[Chilly807]

I'm interested in understanding what you are specifically recommending though.

Assume I get a M7040 for reasons OTHER than specifically running a large rotary cutter though 4" saplings. e.g. having a nice big loader for round bales, a tractor that I can grow with, and the fact that it is pricing out to about the same as a L4740 / L5740.

With 8 to 10 acres of pasture I certainly don't need a 10' rotary cutter. It would also be a detriment for a ditch that I currently mow - just would not be able to do it with even an 8 footer. An 8 or 10 footer is also going to cost me a lot more.

In your earlier post you pointed out the possibility of damage to the engine over the longer term if I mowed with a 6' setup. Is this really the case or am I misunderstanding you?

I am moving up tractors for a cab and a larger loader for round bales. My L3400 is plenty for mowing which I do with a 5' rotary cutter. I'm trying to understand whether there is any real truth to a downside of me not working the tractor 'hard enough' which will affect longevity of the engine. I understand that I will burn more fuel needlessly if I pull the same size rotary cutter that I could pull with a GL4740.

One way or the other, an M7040 is going to be used quite lightly on my current property - compared to how it might be used on a much larger property. Is this a reason not to get it and get a smaller tractor at the same price?

As I understand it, you'd like to buy one tractor to cover your future needs. While I can understand the desire to avoid repeating the depreciation cycle as much as possible, my position is that if you can't use the extra power there's no real advantage to having it. Future needs are something only you can assess, the question was what size cutter to get to suit the 7040.

Our requirements are similar to your current needs, we have a small horse property that we mow a couple times a year, about 7-8 acres in pasture currently. The L3400 we have works a bit when we're cutting, although not to it's full potential. I could have gone to a 6 foot mower and reduced my cutting time by 20%, but under some conditions I think the tractor would have struggled with a 6 footer (meadow grass and alder cutting). So, we picked a 5 foot cutter, RCR1860, and it handles that quite well. I also like mowing, it's a zen kinda thing I'd be finished in no time with even an 8 foot cutter. We do occasionally mow about 18 acres more, which is a full day and a half. That job may disappear next year, so it's not really a deciding factor.

A few times I've thought I'd like to have bought a bigger machine, say an MX5100 for example, but then I say to myself "What would you use it for, really??" More loader capacity would be nice, a little more stability on side hills, etc. I've never run out of power, although traction has been on the light side a few times due to the light weight of the L.

We don't feed round bales however, we're still able to get small squares. I agree with you that the L3400 isn't ideal for round bales at all, and the large rounds are out of the question. I tried to get the right size for the majority of the work we had planned without working it at the limit all the time. We may have to feed rounds in the future, I'm hoping to be able to get 4x4 or 4x5 at the most, or re-bale rounds into squares if we really had to. If not, I'll need a bigger machine, something along the lines of an L4400 would be better for that. We shopped the L4400 when we bought the L3400, and decided we didn't need the extra power and size, and cost was a factor as always.

I don't have an exhaust temperature gauge on the L3400, that's the best indication of how much load is on it. If the max allowed exhaust temperature was 1000 degrees F, I'd like to see 750-800 regularly to get more complete combustion and keep the cylinders and valves clean. I've seen the results of running an engine capable of 1500 horsepower (continuous rating) at an output of 500 HP for sustained periods. Pretty much what I described earlier. A diesel is meant to be loaded to 75-80% of capacity for the best results. Running at 100% isn't recommended for long periods either, but it's not as harmful as low loading.

The problem with farm work is that it's not possible to do that often. Moving bales is no challenge for the 7040, it's a pretty capable machine. If you can't find some serious work for it, it's possible you may have reliability issues with the engine. The rest of the tractor should last forever under light duties. Like others here, that's my take on a situation, they have different opinions.

A six foot cutter will work on the tractor, but in my opinion it's not the best choice. If you need a six foot cutter for some situations, then buy one for those specific jobs. When you can justify a larger cutter for bigger areas, the 7040 will handle a big one. You can offset a smaller mower somewhat to mow up to fence lines, so that's not really an issue.

I'm not trying to be antagonistic, just offering my opinion on farm chores in general (limited experience) and diesels in particular.

Sean

 

[slowzuki]

Just clipping pasture? Small light duty mower is fine on the 7040. Easy to get through gates. We run a 5 ft on a 100 hp tractor from time to time but just mowing grass slowly.

You can offset the 3 point to one side to cut tight to fence lines. We do that when the 5 ft is on the 50 hp tractor.

Clipping or topping is pretty light work. As long as you don't go and plow into a heavy overgrown field with the 7040 working hard you'll be fine.

Some people clip small pastures here with their lawn mower even, and its no load for the lawn mower.

 

[Verticaltrx]

In your earlier post you pointed out the possibility of damage to the engine over the longer term if I mowed with a 6' setup. Is this really the case or am I misunderstanding you?

I think yall are both over thinking this. You will absolutely not cause any long term harm to your tractor by using it at less than capacity. A 6' cutter will work just fine behind a 7040 if that is what you want. Just get one with at least a 65-75hp gear box and don't worry about it.

What Chilly807 is saying has some merit, but unless you are planning on keeping the tractor to 10,000+ hrs I seriously doubt you will notice any difference in service or longevity. My family has tractors that are only used for daily chores (i.e. light work) that have tens of thousands of hours on them.