Is the "5hp. per Mower-foot" Rule Inviolate? Want a 6' MMM on a B2630 vs. B3030

[Gary Fowler]

Re: Is the "5hp. per Mower-foot" Rule Inviolate? Want a 6' MMM on a B2630 vs. B3030

Like Bird says, it all depends on the grass /weeds and how tough they are. I have some grass (I call it wire grass, don't know what it is) that is so tough that it will stall my 60 HP tractor with a 7 foot BH and I have to slow down a lot to cut thru wet areas where it grows proficiently. The guy I bought my B26 Kubota from routinely ran a 5 foot bush hog in waist high grassland with the 19PTO HP but the grass was tender to cut. MMM and rear finish mowers don't take as much HP per foot as a bush hog mainly because the blades are sharper/thinner and turn faster.

You may pull a 6 foot mower OK but have to go slower. At some point the travel speed that you have to go to run a 6 foot compared to a faster travel speed with a 5 foot is going to outweigh the wider mower in production factor. There are just too many variables to say absolutely that it take 5 HP per foot or 10 or 4. Every pasture/yard is different and every tractor's PTO power may be a little less than advertised or less than another model. Each engine runs a bit different and HST models suffer a larger loss at the PTO than a straight gear drive.

 

[My Hoe]

Re: Is the "5hp. per Mower-foot" Rule Inviolate? Want a 6' MMM on a B2630 vs. B3030

Thanks to one and all.

Your answers were VERY helpful.

I apologize for the long delay in following up--to much LIFE got in the way.

Thanks again,

My Hoe

 

[kcender]

Re: Is the "5hp. per Mower-foot" Rule Inviolate? Want a 6' MMM on a B2630 vs. B3030

If Kubota offers a 72 inch mower for your tractor,they must feel it has enough power or they wouldn't make it available.But that would be for normal mowing which I don't think 12-14 inches is.

 

[big bubba]

Re: Is the "5hp. per Mower-foot" Rule Inviolate? Want a 6' MMM on a B2630 vs. B3030

can't go wrong w/advice given here. i would also add that the brush hog weight is also a consideration. a tractor pto hp may handle a given size hog, but be iffy on handling it's weight esp on slopes. assume you have a fel which helps considerably to counterweight the rear load. of course, finish mowers are lighter but can't handle the wider application of heavier duty models..... your manual should give maximum specs for various implements on your model. just to keep in mind imho

 

[My Hoe]

Re: Is the "5hp. per Mower-foot" Rule Inviolate? Want a 6' MMM on a B2630 vs. B3030

kcender,

Re:

If Kubota offers a 72 inch mower for your tractor,they must feel it has enough power or they wouldn't make it available.But that would be for normal mowing which I don't think 12-14 inches is.

Agreed and agreed. 12-14" is not normal mowing height. Good points, both. Thanks.

an't go wrong w/advice given here. i would also add that the brush hog weight is also a consideration. a tractor pto hp may handle a given size hog, but be iffy on handling it's weight esp on slopes. assume you have a fel which helps considerably to counterweight the rear load. of course, finish mowers are lighter but can't handle the wider application of heavier duty models..... your manual should give maximum specs for various implements on your model. just to keep in mind imho

I agree--I really appreciate ALL of the great advice I've received here!

And thank you for your point about the weight of the tractor itself possibly being inadequate. I do know that Kubotas are some of the lightest CUTS, for a given horsepower, as a general rule. I had not considered your point before, because I was not considering a brush hog, but perhaps that's really what I'd need, rather than a finish mower, if I were to mow as infrequently as planned. And I had never considered that brush hogs were heavier, per a given width, than a finish mower, but that only makes good sense, now that you mention it.

Since I don't want to leave the FEL on (as a counter balance to a heavy brush hog), given the number of obstacles I'll need to mow around, I may have to concede that my plan to only mow at (abnormally high) heights is unrealistic, and go with a lighter, finish mower, and be more "normal," and less lazy.

I appreciate the reality check--from all of you. And especially, the courteous diplomacy with which it was given. That's yet another thing that's truly special about this Forum.

Thanks again, to all.

My Hoe

 

[buck boost]

Re: Is the "5hp. per Mower-foot" Rule Inviolate? Want a 6' MMM on a B2630 vs. B3030

Hi all,

I have read that one should have 5hp. for every foot of mower-span--but I'm not sure if this applies just to THP mowers, or to MMM, as well?

I am a fan of the "old" (discontinued in, I believe, 2012) "Premium B" series, comprised of the B2630 and the B3030 (and it's cabbed variants).

<snip>
I just do not like excessive vibration. It's a personal quirk/failing/idiosyncracy and I've accepted it, so I hope you all can, too.

<snip>
However, I believe I want the 6' MMM, instead of the 5' MMM, for quicker mowing time, and possibly being able to get in closer to obstacles, with the wider mower.

I have seen B3030's with 5' MMM's, and B2630's with 6' MMM's--and vice versa.

My Questions:

1. Is the B2630's 19.5 PTO hp. enough for a 6' MMM, given that I want to mow infrequently, at the 12"-14" stage?

2. Should I go with a B3030, given it's 23 PTO hp. if I want a 6' MMM?

<snip>
So...is the B2630's 19.5 hp enough for a "high grass mowing" (think 12-14" or more) or do I need the B3030's 23 PTO hp. for this duty, to run a 6' MMM?

And I do realize that, at 23 PTO hp., even the B3030 does not match the "5 hp. per foot" rule, as it would have to have 30 PTO hp. to do this--and it does not.

Also, does a MMM require MORE, or LESS, hp. per foot, than a TPH-mounted mower, all other things being equal? Or doesn't it matter?

And please--don't spare my feelings--if I've overlooked something in this calculus, please "fire away"--I'm here to learn, not make myself feel good.

Thanks, very much, in advance.

My Hoe

Answers to questions based on my own experiences:

1.) 19.5 HP is plenty for a 6' MMM under normal conditions. 12"-14" is not normal though IMHO. Even with nice sharp blades you will struggle. A 5' rotary cutter is a better choice for that type of length. If you want to chop down that height of grass with the MMM, go with the 5' for sure.

2.) I would try to go B3030. Four PTO hp is actually a lot IMHO.

Your last question about hp requirements between different types of mowers is loaded question lol.

So let me clarify what I'm trying to say. 72" single spindle mower/cutter takes more HP than a 72" three spindle mower/cutter. A lot more.

Rear discharge mowers should use less HP than side discharge.


Hope this helps some.

 

[David Devuono]

Re: Is the "5hp. per Mower-foot" Rule Inviolate? Want a 6' MMM on a B2630 vs. B3030

I with Gary. I have done a couple of acres of 3 ft tall grass and weeds with a 48" bush Hog behind my B4200 with only 10 PTO HP. It could do it, well could not lift the rotary cutter but could cut grass. Then I got tired of mowing in low, 2nd gear so put the cutter on my MF135 and proceeding to cut 8 more acres in the time I cut two acres with the B4200. I would not worry about the weight as its centred and usually has wheels. All my tractors rattle and shake, 1 is 2 cyl, one is 3cyl and my B3200 is 4cyl. Having two gear tractors and one HST, all I can say is with your options, ear protection is a must. (HST is so loud) I love my old Massey, super quiet and comfortable.