Rotary Cutter How to start a rotary cutter?

[john_bud]

I have a quick question, whats the "best" way to start the PTO with a rotary cutter? When I bring the engine to PTO speed and flip the switch it bogs down to ~1500 or 1800 rpm then comes back up to speed. Is that normal? Is there a better way?

Thanks!

John Bud

 

[Bird]

Ouch, that's tough on a PTO clutch. Of course, I don't have the switch you have; I actually have a clutch pedal, so I set my rpm around 1500-1700 engage the PTO lever, then ease out on the clutch to get it started, then use the throttle to bring the rpm up. When I use my neighbor's big tractor that engages the PTO by simply moving the lever, though, I do the same thing; engage the PTO at 1500-1700 rpm, then rev up the engine to PTO speed.

Bird

 

[brewerbob]

I have a JD4300 and a JD530 cutter. The manual says to engage the pto at idle, then bring the rpm up to 2700 (pto speed). The cutter has a shear bolt instead of clutch plates, so this saves the shear bolt.
Bob

 

[DFB]

John, this is what I got for info.

The manual supplied with my JD cutter cautions to; Avoid shear bolt failure at startup by engaging the PTO slowly at low engine rpm..

The sequence described in my operator's manual is to bring the engine up to pto speed and then engage the pto switch

Even though I use a slipclutch and shearing the pin on start up isn't a problem, while running my cutter I felt engaging the pto switch at lower rpms then throttling up to full pto speed made for a smoother transition.

DFB

 

[Anonymous Poster]

<font color=blue>…whats the "best" way to start the PTO…</font color=blue>

On any PTO driven implement, always engage/feather the PTO lever @ low rpm’s {1000-1400 rpm} for minimum shock and to extend the life of all PTO drive-line components, both for the implement end and tractor end… then bring the engine rpm up to PTO (540) speed.

Remember rev’ing that hotrod engine to 3200 rpm as a teenager and popping the clutch…that’s whats happening on the tractor when engaging @ top rpm speed …even if you have a hydraulic PTO/clutch pack… it will take it’s toll in a short time…

_____________________

I’ve been meaning to ask how you like your new Woods 600… I’ve yet to see any of their new series, but I’m possibly interested in “stepping up” to the Woods 7200 or Bush Hog 406. The spec’s on paper and pictures surely look impressive.

 

[Bird]

Well put, John Miller. That's the best answer of the bunch; wish I'd said it that well./w3tcompact/icons/tongue.gif

Bird

 

[hayden]

I'm not familiar with how these controls work on a larger tractor - yours in particular. Is it an electric on/off switch? If so there's no real provision for "easing" the engagement.

Is it possible to activate the tractor's clutch, engage the PTO switch, then release the clutch to more slowly start the implement?

My JD lawn tractor has an electric clutch for the mower, and it's rather abrupt. I end up doing quick on/off pulses to spin up the mower.

 

[GlueGuy]

Youch! /w3tcompact/icons/shocked.gif

Bird & John have already said it well.

I do as the manual(s) say: Engage the PTO at idle, then rev up to PTO speed. When I dis-engage, I lower the RPM to idle, then push the clutch and dis-engage.

The GlueGuy

 

[Joeinindy]

The first time I used my LandPride 6' I had the rpm's up then engauged the pto and the shear pin went. After talking to my dealer he said to leave the engine at idle, engauge the PTO and then bring up the RPM's.

 

[DFB]

Hayden,

Don't know how the other systems do it, but I'll describe the system operation on my HST JD 4100. I don't know if your JD lawn tractor is similar. The panel control switches a solenoid that when energized allows pressurized oil to flow pushing a piston that releases a spring loaded brake (that when normally engaged prevents the clutch shaft from turning), while simultaneously pressurizing another piston to lock the clutch pack (which is keyed to the pto shaft) completing the power transfer from the engine output shaft. (gear coupled) There is also a spring loaded reservoir in the circuit which acts a buffer for the pressurized oil creating a described "soft start" for the clutch. Oil pressure is controlled by both the charge pump and by shims for the spring loaded pressure relief valve. (to adjust the pto clutch pressure for correct operation)

DFB

 

[dmccarty]

John_Bud,

A really good question. My JD 4700 manual, I've read it the section on starting the PTO driven implement three times now, says to get the engine to PTO speed and then engage the PTO implement. I only have one PTO driven implement, an MX-6, and it has a slip clutch so I don't have to worry about breaking a bolt. BUT I don't like engaging the PTO this way since the engine RPMS drops by a good 1000 RPMs getting the cutter up to speed.

But that is what the book says........ What does your manual say to do?

Later,
Dan

 

[cowboydoc]

John,
Mine does the same thing. Even if I lift up the cutter off the ground it still does it. I had talked to a few mechanics about it and they said it was normal.

 

[Anonymous Poster]

The PTO on my Kubota doesn't have a clutch. If i try to engage the PTO with the motor running, it just grinds. So I engage it with the motor off. Doesn't seem to cause a problem. I disengage it before I shut off the motor, though. Takes the thing a minute or so to spin down freely, those cutters have a lot of inertia.

 

[Bird]

Dummy, I gotta ask; what model Kubota do you have?

Bird

 

[hayden]

That's much more complex, and probably less abrupt than mine. Mine's an electrically activated clutch, just like the clutch on and automotive AC compressor. Low tech, abrupt engagement.

 

[john_bud]

Hey Guys!

Thanks for the great replys. My computer has been "goofy" since I added network cards and I just got it seeing the modem again. Whew!

I read the manual, but I guess not real well /w3tcompact/icons/blush.gif. I saw the part about bringing the tachometer to the 540 rpm PTO indication and missed the part about reducing the rpms first engaging the PTO, THEN going to the PTO speed! Doh!@! I will give it a whirl at a lower rpm next time I need to cut.

John Miller asked how I like the Woods Brush Bull 600.
AWSOME! is the word I would use. Built like a tank. A buddy of mine said that the pan on mine is about 4x the size of his 72" cutters pan. I was nervous about picking it off of the trailer with the FEL as the listed weight is about 1050 pounds and the loader is rated at 1050. But I guess there is a lot of underestimation in the Kubota literature, as the tractor picked it up easily. I actually had to drop the engine rpms down to be able to move the FEL slow enough to feel warm and fuzzy. (Attached photo of the loader holding the cutter. You can see the size of the gear box compared to the tractor. What you don't see is the thickness of all of the metal sections, the nice welds and the smooth rounded top.) I still don't have chains. The dealer tells me they are still on back order. But the guard in place is metal about 3/16th thick and it has withstood the abuse of my use with no damage to date.

It isn't really all that noisy to operate, but I still wear the head phone type hearing protection. At a guess, it is a tad quiter to operate than my lawn mower, which is an 18 hp cub cadet 2186 with a 48" deck. It has gone ripping through 3" soft wood trees and 2" maples. No probem. Although I did "find" a spruce tree that was down in the weeds with an 8" trunk. That made some clunking! But not as bad as you might imagine. I think the large diameter blade pan allows it to ride over stuff that it too big to cut rather than letting it get batted around in there. The only time it bogs down is when I go over a gopher mound and it is held up by the blades. Cutting tall grass is also pretty good. Quality of cut is ok, but it isn't a lawn mower!
I can't provide operational comparisons to other units, but I do like this one.


Thanks again for the sage advice!
John Bud

 

[Anonymous Poster]

Brad: an L2850DT, shuttle shift 4x4, 30 something hp/27.5 PTO, late 80's I think. Had it for 6 months or so now.

Seems odd that there's no clutch control for the PTO. Kinda spooky, too. If I need to stop the implement in a hurry my first reaction is to go for the clutch, I need to re-learn and go for the lever instead.

The PTO is totally independent of the gearbox, it'll run whether you're in gear or not, or whether the clutch is in or not. Does that make it a "Live" PTO? Whenever I read a definition, neither the live or non-live PTO descriptions seem to match the way mine behaves.

I like the tractor but my old 9N sure felt more safe when sideways on an incline. I've never tipped one but somehow the Kubota seems like it might, in spots where the old Ford never even hinted it could. The Ford had calcium in it's tires, maybe that's the difference. Love the wieght but hate the way that stuff rots everything it touches. The Kubota gets *real* tippy with a full loader, too, where the Ford never did.

 

[patrickg]

The way they 'splained it to me, my Kubota clutch pedal works both the PTO and tranny. I was told to go to idle RPM, then depress clutch, then engage PTO control, then ease clutch out, then throttle up to PTO speed. I can rub my tummy and pat my head at the same time but still disconnected the PTO at full RPM once.
It coasted for a L O O O O O N G time. Safety manual says wait for it to stop before dismounting from tractor.

Patrick

 

[jdrotert]

I'm kinda new to this diesel compact tractor thing, so bear with me. I am using a 5' Farm King finish mower on my B2150DT. I usually never throttle up to PTO speed (540 rpm PTO, 2467 rpm engine) because the engine seems like its racing. I usually run the engine at about 1700 rpm because the engine is not too loud then. Do I need a new muffler or is the engine supposed to sound that loud?

 

[mlmartin]

Compact tractors are designed to run at full PTO speed for days at a time/w3tcompact/icons/smile.gif Most implements are designed to work best at 540 PTO RPM. At a significantly lower speed, you will suffer with substandard cutting and/or spend more time mowing than you should.

Tractors and implements are generally pretty noisy. If you value your hearing you should be using significant hearing protection. I use AO brand ear muffs. They reduce noise by ~20dB. Hearing protection is something I've always taken seriously and as a result I have far better hearing than most people my age (50).

Matthew