shear pin vs. slip clutch on a brush hog

Soundguy · Jun 8, 2004

I get you.

On my NH the pto engagement lever is manual.. but there is no 'partial' engagement.. it is either in or out.. but you have to clutch it to get it in.. if you move the lever without the clutch in.. you hear metaltometal. But the 2 stage clutch lets you feather it in.. so you still have control.

I gather that the electric solenoid engage units.. just snap in.. and that even at low rpm,, it is still a jolt. Too bad the electric units couldn't control a hydraulic valve.. and simply when you hit the switch.. the hyd valve opens engaging a hyd clutch pack.. that seems like it would be a decent middle ground... still have electric engage/disengage.. but also have the benefit of a clutch lock up mechanism.

And yes.. I agree with you..product liability laws ( lawyers / government ) tend to muck up alot of otherwise 'good' ideas.

Soundguy /forums/images/graemlins/laugh.gif

timb · Jun 8, 2004

Even more ironic - I think on the 4000 Ten JD's you do have an electric switch controlling an electric solinoid controlling a hydraulic valve engaging a hydraulic PTO clutch (or a brake on the way out) and it is still apparently a problem of the PTO engaging too harshly. Sumpin' ain't right in all of that.

IMO the only thing "wrong" with your setup from my idea of the "ideal" user interface is that both of your clutch sets (tranny and PTO) are controlled by the same device - your clutch pedal. If they would de-combine the second clutch set acutation from the tranny clutch pedal and give you a discrete control (lever) somewhere - you've got full control over how the PTO load is taken up without interrupting the tranny action.

It's independent, it's analog, and it provides tactile feedback.

Oh - but I forgot - it's not a 'push button'. Politically incorrect.

Tim

JerryG · Jun 8, 2004

This was what I was asking about a few days ago. If the independent PTO's on other brands, engaged all at once or what I was calling feather touch engagement. Massey has two stage engagement for the independent PTO. It appears that Kioti doesn't. Which way are the other brands made?

GaryS · Jun 8, 2004

for the extra dollars, I'll get the slip-clutch. This will be the easiest part of the whole "new tractor" purchase decision /forums/images/graemlins/smile.gif

When spending sooo much money on the tractor, if this is a small insurance policy against me doing something dumb, it well be money well spent.

rockyridgefarm · Jun 9, 2004

Ok, lessee if he can crawfish a little....

Somehow I think I have given the impression that there is a big problem with my electrically actuated solenoid to the pto setup. There ain't. It works great and it is very ergonomic. Both my wife and I use our tractor a lot, and we both expect to operate all the function intuitively, and safely. It takes less than a flash to get your hand on that pto knob and it is off. To me, that is well worth it. I can hop on there, and even with the seat fully forward and lowered rfor her, still easily operate all the controls.

It may be possible for mechanically actuated controls to be as thoughtfully placed, but they probably would have their own set of problems (like unreliable linkages)

As far as the breaking shear bolts, I was warned by others that I would prefer a slip clutch. I like the idea of a slip clutch, so that was no problem. My old mower did get all beat up, but it was a beat up old mower...

shvl73 · Jun 9, 2004

My Mahindra has an electric actuated pto, I engage it at idle usually & it seems to be no problem at all. My Brushbull & my tiller have slip clutches, my posthole digger & my snowblower have shear pins.

Soundguy · Jun 9, 2004

( IMO the only thing "wrong" with your setup from my idea of the "ideal" user interface is that both of your clutch sets (tranny and PTO) are controlled by the same device - your clutch pedal. If they would de-combine the second clutch set acutation from the tranny clutch pedal and give you a discrete control (lever) somewhere - you've got full control over how the PTO load is taken up without interrupting the tranny action )

Considering that ton the 2 stage clutch, the first level of the pedal moving down clutches the drivetrain ( leaving the pto engaged ).. you are correct.. that it is impossible to clutch the pto without also clutching the drivetrain.

I guess an independent pto engagement lever would do that.. provide it had some sort of soft engagement thing worked into it.

Soundguy

timb · Jun 9, 2004

Guess there are two areas of 'engagement' to be concerned about. One, actually 'engaging' the gear train running to the PTO output shaft to the rest of the powertrain. Sounds like you've got a 'hard' connection there - no syncros, after all, so everything has to be dead still. The other area is in then applying engine power to that output, where the load of the implement is brought on line (hopefully without snapping any shear pins.) There I think you've already got the control level needed via the foot pedal. It's not 'digital' (on/off) - it allows you to ease into the load.

Tim

Soundguy · Jun 9, 2004

Yep.. on the pto engagement.. clutch must be in for it.. heck.. even to shift the tractor tranny.. tractor can't be moving. I also take that to mean unsynchronized.

The 2 stage foot clutch makes it pretty livable though..

Soundguy

OkieG · Jun 10, 2004

Yup, the 855 doesn't have the electric pto engagement, does it 

Just based on comments on this thread, I think you are right. But, there must be some electronic component to it because of the safety switch under the seat. It seems to electrically disengage the PTO somehow. I'm not sure if that has anything to do with how the PTO handle engages the mechanism in the first place.

OkieG