Mowing Violent start of rotary cutter

[DK35vince]

Hey all,
Have a 6' KingKutter rotary cutter on my DK35se.
When I first hit the electric PTO switch to engage, it's a pretty violent start. The whole cutter shakes around for a second or two until it gets up to speed. Fine then.
Is this normal? Just wondering.......

My DK 35 with 6' King Kutter rotary cutter does the same thing.
The independant PTO on these tractors turns on hard. No way to ease them on.
I turn my cutter on at idle or just above , let the cutter shake till it gets up to speed and go.

 

[Dargo]

My last tractor also had an electric PTO engagement setup and it too shook the heck out of my rotary cutter when starting. I specifically deleted the electric PTO when I ordered my current tractor and I have zero issues. Until the manufacturers come up with a way to ease the PTO on with their electric PTO buttons, it's something you'll have to deal with. It's not your cutter, it's the electric PTO engagement setup. If you loosen your slip clutch enough to prevent this issue, you'll smoke it the first time you use it. Sure it has to slip to protect the cutter, but you'd have to adjust the slip clutch to slip at about 10 hp to prevent the hard start to it. At that loose, it will slip constantly when you're cutting and it will indeed smoke. And, yes, I do know this from experience.

 

[Willl]

Ditto what Dargo said, it's not your RC. My late fathers JD 4410 did the same thing.

Wait till you try cranking up a 6" chipper w/ a 'switch'. :confused2:

 

[MichiganIron]

Put a slip clutch on the tractor PTO shaft, they're about $90.00.

Problem solved for starting up about anything.

 

[sweettractors]

Put a slip clutch on the tractor PTO shaft, they're about $90.00.

Problem solved for starting up about anything.

I think like Dargo said, by the time you back the clutch off for a smooth electric over hydraulic cutter start, the cutter clutch would be way too loose for operation. Ken Sweet

 

[Yota_85]

My PTO shaft has a slip clutch on it. And I have loosened it a bit, but for reasons stated here , I didn't want to loosen it too much.

It is good to hear though that others have experienced this with the DK.

The only other thing I run off the rear PTO is the snowblower, and that starts fine.

Also, can sharpen the blades on a rotary cutter? Do I have to worry about them being "balanced" like on a finish mower? Just wondering because I cut mostly grass and a little (very) light brush. The cut in the field is so-so, and unless I go real slow it misses spots. Figured that they don't come real sharp when they are new, in case the owner wants to pound the crap out of them on heavy brush.

 

[jinman]

Also, can sharpen the blades on a rotary cutter? Do I have to worry about them being "balanced" like on a finish mower?

Yes, you can and should sharpen those blades in my opinion. I do it and never worry about imbalance. I use my loader to pick up the rotary cutter and lean it against a tree so I can get at the blades easily with an angle grinder. I grind the edge down to a semi-sharp edge but nothing like a lawnmower blade. That fine edge won't last anyhow. Sharp blades make an amazing difference in cut, but don't ever expect a rotary cutter to be perfect. It's a shredder instead of a mower and just doesn't have the tolerances of a mower deck with a lot of vacuum lift. I sharpen my blades at least once per season and it works well. If all you cut is grass and light brush without ever hitting a rock, then your blades will last a long time. I've "mowed" my rocks several times and they don't grow back like the grass does.

Oh yes... When you sharpen your blades it is also the perfect time to inspect your stump jumper and the blade bolts for tightness. Also, I've had several gearboxes that loosen up and have to be retightened. Sharpening and doing a once-over inspection of the underside of your cutter once per year is minimum maintenance.

 

[MichiganIron]

We've installed slip clutches on several tractors DK Tractors. Works great.

 

[radman1]

I don't see how a slip clutch on the pto is going to help. If the clutch slips on just a start up it is way too loose IMHO. They are meant to slip under much more load than just a start up.

Newer larger ag tractors do have a soft start on the pto to help engage larger pto equipment. I expect some day, the CUTs will have it as well. I recently purchased a JD HX 10 pull type mower for my 60 hp JD 4520. It is a little rough getting that the pto started. I need about 2000+ rpm before hitting the pto button. I would prefer the old manual start up in that situation.

 

[Dargo]

I don't see how a slip clutch on the pto is going to help. If the clutch slips on just a start up it is way too loose IMHO. They are meant to slip under much more load than just a start up.

They won't help. As you noted, if you loosen it to the point where it slips on start up, it will be shot before you cut an acre with it. I suppose if you're really talented you could re-tighten it after it's up and running. I'M KIDDING!! Don't try that unless you want to lose a limb. As stated, a slip clutch in the PTO line won't help this situation. I was foolish enough to try that several years ago and wasted about a hundred bucks. And, no, the guy who suggested I do that wasn't willing to replace the smoked PTO slip clutch!