Rotary Cutter 6' KK rotary cutter problem!!

   / 6' KK rotary cutter problem!! #41  
Re: 6\' KK rotary cutter problem!!

All that may be true and yet no one has really gotten any closer to solving the problem. We have people here with various types of PTOs and various types of cutters including KK, none of whom seem to have the problem.

The facts are that 1) he is shearing pins at start up so for whatever reason, whether it is the tractor or the mower, PTO start up forces are too violent for the shear pin. 2) The blades seem to be hitting at startup. Is this related to #1 or not? I don't know but I don't really see why the blade tips hitting would cause the shear pin to break. 3) Once things start spinning all else is fine.

I don't know if the real solution is to be found in these facts, but it seems fairly safe to say that regardless of where the problem actually is that a slower, gentler start-up would help. Other than that I'm totally stumped.
 
   / 6' KK rotary cutter problem!! #42  
Re: 6\' KK rotary cutter problem!!

</font><font color="blue" class="small">( )</font> Skip

You are correct putting the PTO in Auto mode and slowly letting out the clutch, made zero difference.

Gentler startup didn't help. I would say that there is a different issue than the tractor. /forums/images/graemlins/smile.gif
 
   / 6' KK rotary cutter problem!! #43  
Re: 6\' KK rotary cutter problem!!

</font><font color="blue" class="small">( </font><font color="blueclass=small">( )</font> Skip

You are correct putting the PTO in Auto mode and slowly letting out the clutch, made zero difference.

Gentler startup didn't help. I would say that there is a different issue than the tractor. /forums/images/graemlins/smile.gif )</font>

I read that. I was not sure if he meant that the blades still hit or the blades still hit AND it sheared the bolt. Either way that doesn't change the main things we know about the problem as listed above.

It also doesn't make sense to me. There are forces at startup that break the pin. If slowly and gently applying those forces doesn't help at all, what could it be? The answer might be more obvious except for the fact that once it does get going everything is fine. That would seem to rule out a gear box issue.
 
   / 6' KK rotary cutter problem!! #44  
Re: 6\' KK rotary cutter problem!!

I think that when he gets his Bush Hog or Woods Cutter, his problem will be solved. /forums/images/graemlins/wink.gif
 
   / 6' KK rotary cutter problem!! #45  
Re: 6\' KK rotary cutter problem!!

</font><font color="blue" class="small">( I think that when he gets his Bush Hog or Woods Cutter, his problem will be solved. /forums/images/graemlins/wink.gif )</font>

Well, not really unless he's able to get his $800 back. And I would certainly agree that you'd be less likely to have problems with an expensive name brand mower, but there isn't any reason to _expect_ the kind of problems he's having even from an inexpensive mower that is brand new. I have a hard time believing this is a design flaw in the mower. There are too many of them out there. Just found out a friend of mine has been using a 5' KK for at least 8 years with no problems and this guy is almost uniformaly hard on everything he owns to the point of irresponsibility. It certainly may have a manufacturing defect, and that is what you'd expect from a low end mower. But again, how come it runs fine when it gets going? I know I'm beating a dead horse but for some reason this problem is intriguing. I guess its because it seems like it ought to have a simple soultion but so far it does not.

Regardless, the most telling aspect of the whole situation is the poor customer support from KK. That alone would put me off from buying one.
 
   / 6' KK rotary cutter problem!! #46  
Re: 6\' KK rotary cutter problem!!

</font><font color="blue" class="small">( I have a hard time believing this is a design flaw in the mower. There are too many of them out there. )</font>

So do I. I have the 6'KK brush mower, run it on a tractor with electric/hydraulic PTO. Never had a problem starting the cutter or any type of problem for that matter..
 
   / 6' KK rotary cutter problem!! #47  
Re: 6\' KK rotary cutter problem!!

</font><font color="blue" class="small">( he blades freeswing and hit each other mid-way and on the tips. I don't see how this could be a issue with the tractors PTO )</font>

On a cutter with one stump jumper with 2 blades.. I really don't see how the blade tips touching ( forming rough triangle ) causes any problem with the olt shearing.. unless the blades are touching something else and hanging up.

</font><font color="blue" class="small">( The first cutter did the same exact thing as second one. I engage the PTO at idle speed at 700-800 rpms range. It is frustrating to pay $800 bucks for a cutter and it has a design flaw )</font>

Respectfully.. I don't see any design flaw.. except in the enginer that designed a pto that cannot be feather engaged.

I fthe other mower did it.. that's how it is built.

I have a KK mower.. used it for uears.. have ran a few different Howse mowers.. never ever have i sheard a bolt on startup.

All the tractors I've used were either indepentent pto, or live/2 stage clutch pto's.. or single non live clutches.

Again.. all engaged at low idle and feathered in...

Soundguy
 
   / 6' KK rotary cutter problem!! #48  
Re: 6\' KK rotary cutter problem!!

</font><font color="blue" class="small">( but there isn't any reason to _expect_ the kind of problems he's having even from an inexpensive mower that is brand new )</font>

I agree. I have a 'cheap' howse 10' mower.. Ipump 9hp per foot into that... cut 3" woody trees down accidentally all the time... flatten ant mounds.. etc.... cheap mower hasn't broke yet.. and worked as advertised when i got it.

I think more investigation needs to be done.

Is there damage to the pto shact/yoke where the shear pin goes.. letting the conenction get sloppy then shear the pin? Is there a binding in the gearbox letting force build up/get high between the pto and the gearbox ( leaving the blades/stump jumper out of the picture?)

Does the gearbox turn over smoothly by hand.. and 'hang-up' areas?

I don't see a high dollar unit NOT performing the same way... unless it simply turns smoother... the weak link here is obviously the shear pin, and whatever torque is needed to get the mower rotating. perhaps if a lower gear ratio was use din the 'expensive' gear box.. then less power would be needed.???

In either case.. everyone going back and forth between non-feathered tractor pto, and cheap mower.. doesn't help the situation. A new mower doesn't really help either.. as this guy is still out money..( wow.. 800$ for a 6' KK... prices must be high where he bought his... I can get one for less here in florida ).

Bad bearings binding / grabbing? Chipped gearbox teeth slipping? Blades contacting deck?

Soundguy
 
   / 6' KK rotary cutter problem!! #49  
Re: 6\' KK rotary cutter problem!!

I agree, try rotating the pto shaft leading to the mower by hand and see how it is.

Any chance the shaft is to long/short?
 
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