Chipper Anyone use a PTO chipper?

[grsthegreat]

Stopping the disk is almost nothing for a brake, and if the overrun clutch lets it run for minutes you would have to wait a long time before you could open the housing to clear a clog. If there is no drama starting the disk, then brake should have no problem stopping it. Car brakes can last for 50K to 100K or more and they experience a lot more stress than a PTO brake.

Here is a question, has anyone worn out a PTO brake yet?

i dont know if they actually have a brake per say. id have to look into that further. My older JD would simply continue to spin down the bushhog and chipper for a few minutes till it stopped. There was no physical braking.

 

[BethesdaEC]

i dont know if they actually have a brake per say. id have to look into that further. My older JD would simply continue to spin down the bushhog and chipper for a few minutes till it stopped. There was no physical braking.

My JD2520 has a brake, next time I am running the chipper I will pay more attention to how quickly it stops, but I would guess within a revolution or two.

 

[dgwenzen]

Thanks everyone for the comments and observations. This discussion has been very enlightening.

 

[grsthegreat]

My JD2520 has a brake, next time I am running the chipper I will pay more attention to how quickly it stops, but I would guess within a revolution or two.

something from messicks about pto brakes (didnt know such a thing existed)
About PTO Brakes

 

[greg_g]

My JD2520 has a brake.

Interesting. Didn't realize the compacts had them. So I did a word/phrase search of the online 3720 manual; no PTO brake. It's not my intent to embarrass, but are you sure your 2520 has a PTO brake?

/greg//

 

[RoyJackson]

something from messicks about pto brakes (didnt know such a thing existed)
About PTO Brakes

Another thing about reducing the engine RPM is you're using the inertia (engine braking) of the engine (as RPM drops) to slow the powered implement...less stress on the implement and the tractor (and PTO brake, if installed).

greg_g's post

Interesting. Didn't realize the compacts had them. So I did a word/phrase search of the online 3720 manual; no PTO brake. It's not my intent to embarrass, but are you sure your 2520 has a PTO brake?

I didn't know iof my old 4400 had a PTO brake either, so I looked in the Service Manual:

The PTO clutch provides a means for disengaging the
PTO output shaft from the engine. The PTO brake is
provided to positively stop the rotation of the PTO
system when the PTO clutch is disengaged. The PTO
clutch and PTO brake work simultaneously. Both mid
and rear PTOs are affected by the operation of the PTO
clutch and PTO brake.​

So, my 4400 does and I expect your 3720 does too (as does BethesdaEC's 2520)...but you might have to look in the Service Manual (if you have one) to confirm that.​

One thing I think we all agree on (most of us, at least), is that it not advisable to engage or disengage the PTO at any speed higher then idle.

I think we all learned something today...I know I did!​

 

[Willl]

i dont know if they actually have a brake per say. id have to look into that further. My older JD would simply continue to spin down the bushhog and chipper for a few minutes till it stopped. There was no physical braking.

Same with my 790. No brake.

 

[RoyJackson]

Same with my 790. No brake.

I'm going to make a guess that it's the tractors with independent PTOs that have PTO brakes.
Your 790 has a Live PTO (that 2-stage clutch)...it's still a good idea to engage and disengage the PTO at a low RPM though.

 

[Furu]

Another thing about reducing the engine RPM is you're using the inertia (engine braking) of the engine (as RPM drops) to slow the powered implement...less stress on the implement and the tractor (and PTO brake, if installed).

One thing I think we all agree on (most of us, at least), is that it not advisable to engage or disengage the PTO at any speed higher then idle.

I think we all learned something today...I know I did!

I still don't see the stress on the implement or tractor if pto is disengaged at speed IF you do not have a pto brake. When disengaged my pto free spins. Don't see the stress. I would see more stress on the tractor from pulling the throttle back to idle and having the inertia push the engine unless you reduce to idle over at least 30-45 seconds so that the flywheel inertia effects are never felt by the engine and pto.

 

[BethesdaEC]

I still don't see the stress on the implement or tractor if pto is disengaged at speed IF you do not have a pto brake. When disengaged my pto free spins. Don't see the stress. I would see more stress on the tractor from pulling the throttle back to idle and having the inertia push the engine unless you reduce to idle over at least 30-45 seconds so that the flywheel inertia effects are never felt by the engine and pto.

The only real stress that a PTO chipper puts on the drivetrain is when you use it, especially on hardwoods. Starting and stopping is incidental.