Rotary Cutter Bush hog hp requirements

[Farmwithjunk]

How many here have actually bogged down a rotary cutter? I've read tht 5 HP per foot "rule" for quite a while, but have read of few folks that had issues with their cutters.
First year I had my 5' cutter, it was operated behind a 16 PTO HP tractor. That's less the 4 PTO HP per foot. I had no problems...just use common sense when you operate the unit.

That'd be me. But that's at 5-1/2 to 6 mph mowing wide open flat fields of 3' to 4' tall fescue/weeds. (Done so with several tractors, one where I was running almost 10 hp per ft.)

At normal, slower (read SENSABLE) speeds, I've seen 17 hp with a 6'er do ok.

 

[jbrumberg]

I agree with RoyJackson and Farmwithjunk (as usual ). I have managed to rotary cut some pretty nasty vegetation including ~2" softwood (poplar) saplings with
~4 PTO HP per foot. The "Compact Tractor Bible (2006)" for what its worth states: "The power (requirements) is typically 2 HP per foot of cut for light-duty rotary mowing and 5 HP per foot of cut for brush hogs capable of smashing 2" diameter saplings". The most demanding cutting I have done is ~7A's with 11 PTO HP (Ford 1100) running a 3.3' (Woods M-40) RC and I was cutting 5' - 6' weeds and a lot of ~2" saplings when we bought our property many years ago. I did bog down and stall the tractor on occassion (going too fast) but I was able to cut everything. I will state that I finally killed that RC . Common sense is the key. Jay

 

[greg_g]

How many here have actually bogged down a rotary cutter? .

Me. My Jinmas had 21.5 PTO hp and aggravated the **** outa me with a five footer. I figure I could have mowed an equal number of acres/hour with a four footer, simply cuz the five footer required such slow ground speed.

My KM454 has ~39 PTO hp, and I've slowed a six footer down some in the occasional long wet stuff. But overall it doubles the acres/hour I could do with the Jinma.

My TS354C has ~30 PTO hp, and handles a five footer just fine in all conditions. This is my first summer with it, but it hasn't bogged down yet.

My experience definitely supports the 5hp rule.

//greg//

 

[Soundguy]

Hmm.. I've had to run WOT on my 8n to pull 5' cutter thru 5-6' weeds.. but I guess it ran pretty good. This was 2nd gear inthe 5' stuff.. and 1'st gear in the 6' stuff... was just barely able to keep 540 pto rpm with throttle at max.. good thing it wasn't 6.5' or I'd had to take a 4' bite I think!

I've found that lush thick green grass is much more of a load than tall stemmy weeds that are 2x to 3x as tall as the grass...

Soundguy

 

[JoeinTX]

"I've found that lush thick green grass is much more of a load than tall stemmy weeds that are 2x to 3x as tall as the grass..."

Yeah, agree for the most part.


For the poster, he is at the outer limits of what his rig can do in normal conditions. 26hp to 6'...........okay in moderate conditions but will require a partial swath in thick and thorny areas and additional weight up front to handle the load.


Invader grass/weeds and the odd small tree or bush are easier to handle thank consistent healthy grass growth when cutting.

 

[JerryG]

I have bogged down several tractors with a mower. Tall fescue with thick undergrowth as well as when mowing bermuda. Nothing is as hard to mow fast as bermuda.

 

[Farmwithjunk]

I have bogged down several tractors with a mower. Tall fescue with thick undergrowth as well as when mowing bermuda. Nothing is as hard to mow fast as bermuda.

YEP! One of my pastures has a patch of bermuda about 100' X 200'. Even if I'm only cutting a couple inches, you can hear the tractor laboring as I pass through it. Tough stuff to get rid of too.

 

[wolc123]

I can relate to soundguy's post. My 8n did not do so good on thick grass with a 5ft bush-hog squealer. Had to run wide open, 1st gear and take a partial cut. The Ford 2000 diesel I replaced it with handled this cutter with ease. The n's just seemed weak thru the pto but it was equal to or better than the 2000 pulling a plow so it certainly had no problem applying the drawbar hp.

 

[RoyJackson]

Boy...I just slow down a bit...other then a few seconds waiting for the engine to catch up...can't say I've ever had a problem.
Now, due to the terrain, I do go slow (2nd gear which is..maybe 1.5 MPH) and on some sections, 3rd low (2.5-3 MPH).

 

[Nick Danger]

Based on my experience to date I think this is a good rule of thumb. I have 8 PTO hp per foot (6 ft cutter and 47 PTO hp) and I find that this setup is massively overpowered.

If you had a hair on your... you'd realize you can NEVER be "massively overpowered"... :thumbsup:

As I leave, Tim Allen's warcry playing in my head...