Why Can't Someone Make a Good 12' Batwing Cutter?

[rockinbbar]

I retired from John Deere... put many tractors and mowers into production over the years. It's ok to disagree. ;<)

I'm not saying tip speed doesn't make a difference. I'm saying it's not the whole story and "faster is not always better".... you pay a big price in power concumption to swing the blades fast and often the cut is not improved.... especially if you bog in tough cutting (finish or rotary cutters).

I little secret: spindle placement is HUGE. Tire tracks from the power unit push the grass forward and mash it down. If mid mount and rear mowers designers had their way... they'd place the 'back sweep' side of the mower blade to mechanically lift those tracks. They can't! That's why front mount mowers and ZTR's out-cut everything. The designer can tweak the front caster wheel placement to coincide with the back sweep behind it.

Yeah, I tend to match the horsepower with the cutter, to minimize slowdown and maximize cut performance.

But I do several things as well. Ground speed, keep blades razor sharp, corners blunted, and turn direction of tractor adhered to. Small things make a difference.

Big change in performance and cut with my HD cutter when I went from 100hp to 120. For the vast majority of my projects, the added horsepower allows me to cut without lugging the engine, and slowing the cutter.

 

[dieselscout80]

But I do several things as well. Ground speed, keep blades razor sharp, corners blunted, and turn direction of tractor adhered to.

Question what do you mean by turn direction adhered to?

 

[rockinbbar]

Question what do you mean by turn direction adhered to?

On a good cutter, all 3 cutting decks don't turn the same rotation direction, so when you turn one way or the other, you may notice a poorer cut.

Mine cuts better when I make a turn, or circle a tree counter clockwise. The only difference would be the direction the blades are spinning.

I also try and not turn too sharp, as the main drive shaft gets more pressure on it from a sharp turn, than a gradual turn. Those CV joints and shafts are expensive, and I litterally slather the CV joint with grease daily to cut down that wear. Last one made it 11 years and was still tight.

 

[dadohead]

On a good cutter, all 3 cutting decks don't turn the same rotation direction, so when you turn one way or the other, you may notice a poorer cut.

They counter-rotate the blades to mechanically "back-sweep" the tire tracks. In a turn though, the tire tracks can run out of the back sweep and move into the forward sweep portion of the cut. The tire tracks arent cut well and stand back up in a few days. No amount of tip speed can fix it either. Spindle placement is huge!

 

[rockinbbar]

They counter-rotate the blades to mechanically "back-sweep" the tire tracks. In a turn though, the tire tracks can run out of the back sweep and move into the forward sweep portion of the cut. The tire tracks arent cut well and stand back up in a few days. No amount of tip speed can fix it either. Spindle placement is huge!

Tip speed and spindle placement seem to be your strong points.

Please inform me as to my options on spindle placement in the field cutting brush. Not sure why you think that I believe tip speed fixes anything, other than I'd rather have a higher blade tip speed, all other things equal.

And yes, my tractor pulls my batwings, so how do I avoid them pushing the grass down as I mow with a tandem pulled cutter?

I do have a front mounted cutter for my CTL. 6 foot Modern Ag. I reckon I can position that spindle in front, but am unsure of the tip speed because it varies depending on the hydraulic flow of the machine. But it sure doesn't cut nearly as good as my batwings do.

 

[dadohead]

But it sure doesn't cut nearly as good as my batwings do.

Ha, you can't compare mowers unless they are set to the same HOC, run at the same ground speed, and cut in the same grass side-by-side. I'm done here... good luck.

 

[MtnViewRanch]

How about a Bush Hog 12' cutter?

3112 Flex-Wing Rotary Cutter - Bush Hog

bushhog.com

There used to be a guy on the tractor forms who cut highways for a living. All he used were Bush Hog brand mowers

 

[Brown Dog]

I absolutely don't agree with you that blade tip speed doesn't make a difference … When shredding ranches with 3-5 foot of brush growth, a higher blade tip speed means that I get a cleaner cut, and have to circle back less often to cut down the stragglers …

I totally agree with you.

I had to over rev my JD MX10 to get it to cut good.

My BH 2815 with faster BTS cuts way smoother.

I’m all about a faster BTS in all my grass cutting eqpt

 

[rockinbbar]

Ha, you can't compare mowers unless they are set to the same HOC, run at the same ground speed, and cut in the same grass side-by-side. I'm done here... good luck.

Thanks so much for your engineering contributions to this thread!

Yeah, I know you can't compare cut on a CTL front cutter and a batwing cutter... That would be like comparing finish mowers cutting country club greens to batwing cutters shredding pastures.

I just put that out there because I, or anyone else don't have many options about "spindle position" when pulling a batwing cutter... which is what this thread was about from the onset.

Have a great day!

 

[dieselscout80]

On a good cutter, all 3 cutting decks don't turn the same rotation direction, so when you turn one way or the other, you may notice a poorer cut.

Mine cuts better when I make a turn, or circle a tree counter clockwise. The only difference would be the direction the blades are spinning.

I also try and not turn too sharp, as the main drive shaft gets more pressure on it from a sharp turn, than a gradual turn. Those CV joints and shafts are expensive, and I litterally slather the CV joint with grease daily to cut down that wear. Last one made it 11 years and was still tight.

Thanks for explaining it.