Happy Ending...2400 Beat at 400hrs

[patrickg]

Amen to that, Bird! Even with a cab, once significantly above idle things start to get noisy. Many dB difference between 2200 and 2600. I carry and use, at higher RPM, a good set of muffs (like for a rifle range) and am considering the active cancellation type even though I think they are significantly over priced. (and to stay in character, here's an anecdote) Once upon a time in a Physics class far far away, I told the prof (highly esteemed acoustician, consulting expert) of my idea for active electronic noise cancelation using planar speakers as acoustic tile. He laughed me out of his office (about 1969). I went on to optics and other topics where the ridicule index was lower. (fast forward a few decades) And now kids you can buy active noise cancellation in your car's audio system to cancel engine and road noise or ear muffs just like Rutan and Yeager wore to fly non stop around the world without refueling.

Patrick

 

[patrickg]

Alan, On the surface your analysis is plausible, but is, in fact, specious. About the surface, I'm not mowing a putting green/billiard table. I'm mowing pasture or worse most of the time and can only tolerate going so fast over the terrain. I have the seat ride adjustment hardened to to max. I thought at first that it would be a function of toughening up like after not riding a road bike with a hard saddle for a while and needing time to get conditioned. Well, I have conditioned but (pun intended) I'm still bottoming out the seat cushion and hitting my head on the cab ceiling if I try to go too fast for conlditions.

Most of the time I can mow just as fast at 22-2400 as I possibly could at 2600 or 4600 if it would run that fast. My limiting factor is usually terrain (except when "logging"). When the dealer empirically determined 2200 was fast enough it was on a pretty smooth grass only situation though, so terrain was not HIS consideration. Now being over 50 hours, I have a choice and can use more RPM when it suits the situation. I suppose my HD 6' brush hog has more inertia than most 6 footers or smaller units so I may need less stored kinetic energy in the blades to carry me through the odd tough spot and I have a bit more torque and HP (even at reduced speeds) than smaller units (40 PTO at PTO speed).

I have gone to length explaining my situation so others can decide how or if what I report can be interpolated or extrapolated to aid them in theirs. I make no claim that what I am doing is "righter" for anyone than what they have heard learned elsewhere.

Patrick

 

[looch]

patrickg, just to clarify. I did state that

<font color=blue>the cost of replacement blades justifies a proper tractor break-in period</font color=blue>

My question is: Can (slightly) lower than recommended PTO speeds harm the implement? Since you indicated that you prefer to run them at a slightly slower speed than 540, have you noticed any problems?

And as for noise, couldn't you use the same argument (if your answer to the question above is "yes") that maybe a little more noise is worth saving the equipment?

 

[patrickg]

patrickg, just to clarify. I did state that

the cost of replacement blades justifies a proper tractor break-in period

Gee, I guess we're in violent agreement.

My question is: Can (slightly) lower than recommended PTO speeds harm
the implement? Since you indicated that you prefer to run them at a
slightly slower speed than 540, have you noticed any problems?

None whatsoever, so far, just under 60 hours. My basis however is not my personal experience, extremely limited, but on the recommendation of my salesman/tech advisor who put himself through college brush hogging and is a born and raised rancher who still keeps stock and lives on a working ranch (horses and cattle).

And as for noise, couldn't you use the same argument (if your answer to
the question above is "yes") that maybe a little more noise is worth
saving the equipment?

I use hearing protection and will probably be getting more, so it isn't a noise thing for me. Bird commented on how less noise was a benefit to which I commented, AMEN. Less noise is better but I don't adjust my tractoring based on noise comfort. I try to do what makes sense and then ameliorate the peripheral factors like noise. I do adjust my tractoring for ride comfort, it is just too bumpy to go as fast as I would like. I used to jeep offroad through Baja at speeds that would give me a headache and have to slow down till I felt better then do it again and this was with a far better suspension than a Kubota L4610. I got it out of my system (still got a dune buggy though).

Any of you real experts out there want to jump in regarding the pros and cons of running as much as 15% under the rated PTO speed on a brush hog?

Patrick

 

[looch]

Yup, violent agreement. With me it's just a case of new owner paranoia - which I imagine is not too uncommon. Brand new tractor and brand new implements - and I don't want to harm anything. Slightly comforting is what Bird said in his response to ckless about the manual specifically mentioning to avoid "full speed" as opposed to "full PTO speed."

Paul

 

[glennmac]

As to noise, I have taken to wearing hearing protectors all the time.

Noise aside, I have difficulty thinking of any benefit of running a brush cutter below rated pto speed. That's the speed it was designed and manufactured to run at. That's the speed that will produce the optimal blade speed for the type of cutting it was designed for. The gearbox hp ratings for cutters typically far exceed the pto hp of the tractors driving them. If Patrick has a heavy duty Bushhog cutter I'll bet its gearbox rating dwarfs his 4610's pto hp. How can an implement be "harmed" by running it at the blade speed it was designed to run at? Of all the things that can--and inevitably will--harm, damage, ding and bash a brush cutter, I don't think proper pto speed is one of them.

What I do know from experience is that running a cutter below pto speed will degrade and diminish its ability to cut properly. I have from day one run all implements at pto speeds. In the instances where I have mistakenly run my Woods medium duty cutter below pto speed, there was a definite tendency to bog down and incompletely cut things. Sometimes this even seemed damaging or even dangerous. For example, a branch that might be pulverized at pto speed might be incompletely cut and jam in the cutter, or be shot out of the cutter in an incompletely cut state.

If you are cutting woody stuff your cutter is going to produce sounds akin to an artillery battle or Armageddon. That's normal. And fun.

 

[Bird]

<font color=blue>I recall folks that were so enamoured of their ability to downshift through the gears and use compression braking A N D S A V E O N T H E I R B R A K E S that they did it virtually all the time, mindless of the fact that clutches were more expensive and more difficult to change out than brake shoes</font color=blue>

/w3tcompact/icons/laugh.gif/w3tcompact/icons/laugh.gifPatrick, I'm old enough to have learned to drive with a manual transmission, started working as a cop when all the cars had manual transmissions, and always ran down through the gears as I slowed down (unless it was a sudden, unexpected need to hit the brakes), and while your comment that clutches are more expensive and difficult to replace than brake linings is, of course, right, I've never had a clutch replaced on any vehicle I've driven, except for one under warranty because they left some bolts out when they built the car./w3tcompact/icons/laugh.gif

Bird

 

[GlueGuy]

<font color=blue>just like Rutan and Yeager wore to fly non stop around the world without refueling</font color=blue>

Actually the DNR headets that Rutan & Yeager used were prototypes from Bose; hand soldered no less. They failed on the 3rd day from moisture & corrosion in the circuitry. When Dick & Jeana landed, they had spent 6 of the 9 days in a pretty noisy environment. According to their book, they both sustained a 15% permanent hearing loss.

I hope that the ones we get these days are a little more reliable. /w3tcompact/icons/crazy.gif

The GlueGuy

 

[ckless]

Wow, quite a response and good ones too. As for this unit, I'll only be running a 4' bush hog and I hope to look for a mmm since I have a ton of trees and will keep most of them(including an acre of planted pine). I'll probably take it easy on the bush hog, keep the RPM's where the unit seems most happy and keep the blades very sharp(this is also very important in my opinion). And yes I wear hearing protection. As a youth(or 'yute' as Pesci would say) I lost 25-30% in both ears due to a fondness for guns and hanging out at my father's workplace where they overhauled jet planes and other aircraft. I am told that the high, loud noises(like a gunshot) are actually potentially less damaging than a loud, continuous noise, such a running a chainsaw or tractor for hours on end. Your ears actually lose the ability to 'recuperate' from prolonged periods of noise whereas they may recover from a sharp, loud sound(provided it doesn't cause the drum to rupture). I use muffs, similar to what I use on the gun range, and the soft foam variety of the plugs depending on my activity. I take the jokes and ribbing from neighbors and friends about being a wimp and return the favor when I ask them a question and they go 'What?' and I say 'What's the matter? Are you deaf?' Save your hearing or you'll miss out on 1/5th(of your senses) that life has to offer...

Happy Tractoring!

ck

 

[looch]

ck,

Unless you'll only be cutting grass or grass-like material, keeping the blades sharp isn't a good idea. Small trees are dealt with much better by shattering them with a dull blade rather than slicing them off clean with a sharp one: less chance of a punctured tire and they'll rot more quickly. Again, though, if you're only cutting grass, sharp is fine.

I love bush hogging.

Paul