RPM-BUSHHOG
- Thread starter AMP762
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JohnMiller3
Elite Member
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- Jan 15, 2001
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- Capital District, Upstate New York
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- Satoh S650G, MF135, MF165, JD5205
<font color="blue">...do you run at 540 pto rpm and adjust ground speed accordingly... </font>
Yes... if I understand your question... all U.S. PTO driven implements are optimized to work @ 540/1000 rpm... (most Cat 3 stuff (or over 80 PTO hp) is 1000 rpm- not for compacts)
If I have a wide open regular field, I'll be going 5 - 5 1/2 mph with the rotary cutter... and will always adjust my ground speed according to the terrain I'm cutting, whether that means downshifting or upshifting a gear or two to keep my engine rpm's for the "sweet PTO" range...
If you are mowing a field with creeks/dips/ruts/hills/obstacles/overhanging tree branches... you have to adjust your ground speed for safety reasons, but still maintain the PTO speed @ 540 rpm for the proper operation of the implement...
For example if you greatly reduced your engine rpm to reduce your ground speed... then the implement PTO speed will also be reduced accordingly... it would be tough cutting brush say @ 250 rpm and also trying to prevent your engine from stalling out... (unless you have lots of torque reserve)...
Some implements may have a wider/better tolerance for less then the optimum PTO 540 speed...
Yes... if I understand your question... all U.S. PTO driven implements are optimized to work @ 540/1000 rpm... (most Cat 3 stuff (or over 80 PTO hp) is 1000 rpm- not for compacts)
If I have a wide open regular field, I'll be going 5 - 5 1/2 mph with the rotary cutter... and will always adjust my ground speed according to the terrain I'm cutting, whether that means downshifting or upshifting a gear or two to keep my engine rpm's for the "sweet PTO" range...
If you are mowing a field with creeks/dips/ruts/hills/obstacles/overhanging tree branches... you have to adjust your ground speed for safety reasons, but still maintain the PTO speed @ 540 rpm for the proper operation of the implement...
For example if you greatly reduced your engine rpm to reduce your ground speed... then the implement PTO speed will also be reduced accordingly... it would be tough cutting brush say @ 250 rpm and also trying to prevent your engine from stalling out... (unless you have lots of torque reserve)...
Some implements may have a wider/better tolerance for less then the optimum PTO 540 speed...
RoyJackson
Rest in Peace
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First time I cut our lower section of the property, it was 1s gear Low Range. This is about 7/10th's of a MPH, so it's pretty slow. Now, that's at the rated PTO RPM (2600 or so on my 670). The brush was as tall as the tractor hood (or taller, sometimes). I went slow enough to react to any stumps or debris I couldn't see (too thick to do a walk through effectively).
After that first cut, and the finishing mower work is normally 2nd or 3rd gear low (still pretty slow, but my property is somewhat sloped and rutty).
But, you do need to run at the rated PTO speed for your cutter (or mower) to work efficiently.
After that first cut, and the finishing mower work is normally 2nd or 3rd gear low (still pretty slow, but my property is somewhat sloped and rutty).
But, you do need to run at the rated PTO speed for your cutter (or mower) to work efficiently.
Bird
Epic Contributor
I always did it the same as John and Roy; keep the implement running at the 540 PTO speed.
EdKing
Platinum Member
I have to agree with Bird, John, and Roy on this. The only PTO driven implement I run below 540 rpm is a post hole digger. With a brush hog you want those blades spinning fast to get a good cut.
chrisjbell
Platinum Member
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- Jul 17, 2000
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Yup, you mow to the implement speed, which should be 540 for brush hogging.
I have hydrostatic so what I do is set the RPMs to spin the PTO at 540 (or a touch higher) while stopped, then use the pedal to go as fast as is practical while not slowing the engine down. Going uphill or in really thick stuff I'm moving pretty slow, downhill or thinner stuff I can go quite a bit faster.
I have hydrostatic so what I do is set the RPMs to spin the PTO at 540 (or a touch higher) while stopped, then use the pedal to go as fast as is practical while not slowing the engine down. Going uphill or in really thick stuff I'm moving pretty slow, downhill or thinner stuff I can go quite a bit faster.
frank_f15
Super Member, Rest in Peace
you always run at pto speed and adjust groung speed as needed, one of the great advantages of a hydro tran.
SageBrush
Gold Member
Well I must be a black sheep /forums/images/graemlins/smirk.gif
I run my cutter below 540 in "light" grass sometimes. I use a Bush Hog for country lawn cutting and get very nice cuts. I tried it at various speeds and it cuts my rough areas well at 480 or so. I can hit the foot throtle on hills. I run wide open (2600 rpm) in thick / tall grass and use 6th or 7th gear, if the grass is under three foot and dry I increase my speed up to 9th gear max. 10th gear jumps the speed up a bit to much for cutting on my GST L4330. As long as the engine dosen't bog and you get a cut to your standards go for it. I can't tell the differance between 480 or 540 pto speed on my yard grass. I guess it would also depend on your tractors hp.
I run my cutter below 540 in "light" grass sometimes. I use a Bush Hog for country lawn cutting and get very nice cuts. I tried it at various speeds and it cuts my rough areas well at 480 or so. I can hit the foot throtle on hills. I run wide open (2600 rpm) in thick / tall grass and use 6th or 7th gear, if the grass is under three foot and dry I increase my speed up to 9th gear max. 10th gear jumps the speed up a bit to much for cutting on my GST L4330. As long as the engine dosen't bog and you get a cut to your standards go for it. I can't tell the differance between 480 or 540 pto speed on my yard grass. I guess it would also depend on your tractors hp.