Posted in attachments too My friend mowed some brush with his new Deere 333E CTL and new brush cutter for me the other day. When he stops the mower it makes a terrible (to my ears) noise, like a shuddering screech down to stopped speed. It just doesn't sound right to me and he has no clue, just says it's always done it. he's probably got 50 hours on the ctl /mower and he's already been through a hydraulic motor on the mower. Anyone with same/similar setup can comment on this issue? The noise comes from the CTL not the mower and it stops in about 3 seconds.
Sounds like the aux valve port relief opening up when the valve slams shut. Something with a lot of kinetic energy spinning you usually want a check valve to allow crossport flow as it spools down, but if the mower can be run in both directions that's not easy. What kind/make/model mower is it?
I don't know the technical term as to how the hydraulics are cut off, but the noise is normal. The blades don't carry speed and "coast" to a stop like a pto driven brush hog. They just stop.
Looks like we were typing at the same time. I knew someone more tech-saavy would explain it.
he's getting me the make and model on the mower. I know all that rotational energy has to go somewhere but is there a ramp down function on the hydraulics or is there some setting to make it behave like an overunning clutch or is it really ok to hammer that relief so often and hard?
Mower is a blue diamond extreme duty 72 inch.
The point lantraxco made about whether the mower runs in one direction or two needs to be addressed first. If it only runs in one direction, it is an easy fix by plumbing in a check valve between the two motor ports.
Mfg site gives the following specs Custom purpose built motor and relief block out last industry standard motors External cross-port reliefs protect motor versus internal relief valves... So I'm assuming the idea behind the 'External cross-port reliefs protect motor versus internal relief valves' is to allow the oil to just go in a loop around the motor when it's acting like a pump? and maybe the noise is actually coming from the relief block at the motor?
Well, supposed to have crossport reliefs and braking according to the website. I would have several questions especially keeping in mind there's already been one motor failure: 1) Is the motor properly sized for the machine's available flow? If he has a high flow machine, it can push I think 34 GPM? 2) Are there in fact crossport reliefs on the motor, and what pressures are they set at? Does this manifold have the braking check valve built in? 3) If this mower is designed to rotate in one direction only (no reason to reverse it, it's rotary) is it connected correctly and turning in the correct direction? Just for starters, but then I'm a curious sort. Try to get the model number off the hydraulic motor and the flow spec for the CTL, if it's standard or high flow.
Yes, as well as allow some cushion for spin up, and also probably has much lower pressure settings than the machine's valves do, the Charlynn motors they're using typically are rated below 3,000 psi.
I'll call mfg and see if noise is acceptable. Thanks.
They use a eaton Charlynn 2000 series. They do not like shock. Most Blue Diamond mowers are bi directional. Does the operator idle the engine down BEFORE he cuts the mower hydraulics off?
He says it makes the same noise whether shutdown at full speed or idle. So i think he mostly shuts it off at full speed.
per mfg, noise is normal. Thanks for replies.
all of our mowers and brush cutters coast down. if it is dead heading the pump, that is bad and would crap a pump in a hurry
I have a diamond mower we run on a asv rc100 and Iit coasts to a stop. It runs very freeley and for quite a while when spinning to a stop even at idle. I never shut it down at full throttle. I always idle down.
I have a CID mower and it has a check valve between the lines that hook to the motor to prevent this. It coast to a stop probably takes close to 5 minutes. The mower was advertised as bidirectional and the blades have cutting edges on both sides. However I figure you would need to reverse the lines to use the other side of the blades if the check valve is being used.
So you went through one motor already because? Something to do with the noise or
I have a bobcat t740, with rs72 cutter by JD. I get that same chatter when I tilt or raise boom when Im mowing. Only does the chatter on the raise/tilt, and on the disengage of the hydraulics as mentioned above. Hydraulic halve seems to heat up pretty quik during operation. Cutter has 10 hours on it. any idea on a remedy for the chatter?
My Diamond does the same thing. I don't think they are supposed to just stop. My mulcher and rock hound mulcher for my mini ex doesn't just stop either, they coast. There is a lot of momentum there to just stop. The mowers/mulchers use that momentum to help cut, where does that momentum go when they just stop instantly? Seems like a short lived system to me.
I talked to the manufacturer, and they said this was common on the stop. the momentum of the wheel actually turns into pump drivivn by the wheel instead of motor driven, safety mechanism he said. My deal is when mowing, if i boom up or tilt up the same thing happens.
That is because you are robbing flow from the attachment to raise the boom and/or tilt the bucket. Less flow for the attachment, it slows down. If there is not enough flow to keep up with the attachment, then the motor overruns, creating the noise.
I gotta say our 97-2 Kubota runs our 6’ Diamond mower very well. It doesn’t. Slow much at all when lifting while cutting and never runs hot at all. It’s a perfect match. The drum mulcher is a different story. It’s far more taxing on the hydraulics