Rotary Cutter How to start a rotary cutter?

   / How to start a rotary cutter? #1  

john_bud

Super Member
Joined
Sep 23, 2000
Messages
6,596
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

35-43507-little_tractor.gif
 
   / How to start a rotary cutter? #2  
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
 
   / How to start a rotary cutter? #3  
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
 
   / How to start a rotary cutter? #4  
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

18-30366-dfbsig.gif
 
   / How to start a rotary cutter? #5  
<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.

18-35197-JD5205JFMsignaturelogo.JPG
 
   / How to start a rotary cutter? #6  
Well put, John Miller. That's the best answer of the bunch; wish I'd said it that well./w3tcompact/icons/tongue.gif

Bird
 
   / How to start a rotary cutter? #7  
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.
 
   / How to start a rotary cutter? #8  
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
 
   / How to start a rotary cutter? #9  
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.
 
   / How to start a rotary cutter? #10  
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

18-30366-dfbsig.gif
 
 
 
Top