Mowing Violent start of rotary cutter

[Yota_85]

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.
It's so violent at start that it keeps breaking my safety chain on the cutter side of the PTO shaft. (well pulls the clippy end thingy apart anyways)

BTW: I engage the PTO at low RPM (idle-1200 rpms) then wait a few seconds for the shaking the calm down, then increase rpms.

Is this normal? Just wondering.......

Should I try this at higher rpms? I haven't because I just assume it'd be worst.

 

[Frog5234]

Have dk55 and mine does the same. It has worked like this since new.

 

[MichiganIron]

We have put slip clutches on some the DK tractors with the electro-hydraulic PTO engagement. It helps smooth out the start up on brush cutters.

Hope this helps

 

[gauthier]

I bet its the cutter,not the tractor,the blades when stopping and when pulling,will stop unbalenced,maybe squirt some spray lub,up under/around blades and make sure they are still all there,plus I think as things wear[gearboxes etc],things get like that maybe,anyways mine does it too on start,not that violent,but it does it,you can push clutch in[mines gear],let blades really slow down but not completly stop,than let clutch out quick and it will stop vibrating,might have to do it a couple times,My blades have been on since new[10 years ago or so,bet the blade hole,or bolt is wore,that sounds like a likely reason?,might change them this winter.

 

[sweettractors]

The cutter blades are getting crossed when it is stopped and when you restart, it takes a while to throw the blades out to operating position. Always start slowly at lower RPM and with the cutter slightly off the ground. Sounds like the tractor PTO is kicking in very abruptly. Ken Sweet

 

[rvaitor]

Have dk55 and mine does the same. It has worked like this since new.

I've got a 7ft cutter and generally keep the idle down to ease the transition, especially since this single spindle mower has a lot of weight to get moving and depending on the position of the blades can be a pretty good shock.

 

[Yota_85]

We have put slip clutches on some the DK tractors with the electro-hydraulic PTO engagement. It helps smooth out the start up on brush cutters.

Hope this heplps

It has a slip clutch in the PTO shaft. Not sure if there is a way to "soften the transition with an electric PTO. (like, the equivalent of, as someone pointed out slowly releasing the clutch) As another poster pointed out I'll look at the blades to see the position before engaging next time.

But engaging PTO at 1100 rpms is the right way to start, yes?

 

[doall]

I don't guess there is a way to slowly engage pto with electric. but I have to ease my pto on with a brand new bush hog or the blades will hit together so hard it will shear the pin (knew I should have opted for the slip clutch). But no problems if I engage slowly at low rpm. But it is a scary sound, sounds like there is a problem but they all do it, just not all the time.

 

[Big Wave D]

I have a friend that lets me borrow his rotary mower. One of his blades is slightly tweaked/bent. Sometimes it gets crossed with the other blade and won't let either swing into their natural positioning when the PTO is engaged. The whole mower shakes and shudders rather intensely when this happens. I wonder if you haven't got a similar situation.

Just something you might look at.

 

[KiotiDave]

Yota,
Check your (rotary cutter)owners manual and make sure that the clutch actuallyslips and is not too tight or stuck. This could damage your gearcase in the event of a strike. The electric over hydraulic PTO clutch will grab at any speed, you are better to keep RPMs low and make sure the slip clutch slips.
Dave G
KiotiDave