Do you mow at 540

[cp1969]

6 db huh? that can be a huge amount of SPL... you really think it cut your sound by a wide factor like that... considering sound is non linear.. etc

Soundguy

It is a huge amount of reduction. Maybe it's 3 db...whatever cutting a sound pressure level in half amounts to, in decibels. Somebody else can look it up if they want. The bottom line is, at rated speed, I tend to use ear plugs and I don't enjoy wearing them. At 1800-1900, no earplugs needed or wanted.

There...are the flyspecks picked out of the pepper sufficiently now?

 

[Neophyte]

Not to get off topic but I looked at PineRidge's website. Great job on your project descriptions and pictorials at the bottom of the page!

 

[Propertymaint]

Wow! I think the summer heat is getting to everyone. I think we should call this one a draw. Hats off to Sound Guy - he hit us non-540 pto rpm guy's with four posts in a row. As a famous man once said "Get-R-Done!" (By the way, I mowed 5 hrs straight yesterday below 540 PTO rpm!)

 

[JoeL4330]

Every tractor model and/or brand is different. But in general, the RPM where 540 RPM PTO speed is achieved is USUALLY not where peak HP is achieved. Sometimes it's quite a bit different. On one of my tractors, 540 rpm's on the pto is at 1700 engine rpm. Peak HP is at 2250 engine rpm. At pto speed, hp level is (according to some old specs I have) 15% less than peak HP. That isn't uncommon. Most farm tractors I've been around will have the 540 rpm pto speed marked in some manner on the tach. Also, you'll find a "do not exceed" mark for pto use that's a tad faster and closer to peak engine hp output.

In the end, this isn't rocket science. So long as the engine pulls the mower (or whatever pto load is) and it cuts like you'd expect, it isn't all that critical what rpm you run at. However, in about every case I've seen, mower performance, as well as engine performance is better when you operate at or near manufacturers suggested levels. There are exceptions to every rule. In tough conditions, I'll run at or near that peak rpm level.

It's always been my thinking that the people that designed and built my equipment may just know more about the subject than I. When they give me a suggestion on how to operate it, I listen. Until someone or something proves that wrong, I'll stick with what got me here.

I believe you will find that 540 is just beyond the torque peak (and therefore below the HP peak) The reasoning is that if you are just over the torque peak and the engine wants to bog down, the torque increases a tad and usually pulls you through

 

[Farmwithjunk]

I believe you will find that 540 is just beyond the torque peak (and therefore below the HP peak) The reasoning is that if you are just over the torque peak and the engine wants to bog down, the torque increases a tad and usually pulls you through

That's true on SOME tractors. Not ALL. Some brands use a basic platform (gearbox/rear end/ect) and attach various engine combos. (More common in older models) Sometimes it isn't nearly as scientific as we would choose to believe. But as a genaralization, you are correct.

 

[Bob_Young]

Well it's obvious to me, now that it's been explained, that the reason the engine and mower make so much noise at 2600/540 is so that everyone will know that you're running at 540. Nothing really bad could ever happen at that speed but the racket is important because it informs others that the proper PTO speed is being used.

Someone who is QUIETLY mowing, on the other hand, is up to something. Probably thinks he's saving fuel or part wear or blades or something really underhanded like getting more seat time for fuel consumed. This is UNFAIR and cannot be permitted. Its a job for Dum...de...Dum...Dum, the PTO POLICE! ;^)

Back when I was learning how to hand start a John Deere A, nothing had tachometers; at least nothing I ever operated. This included the Johnny Popper letter series; Farmall H, M, and C; and, my favorite, the mighty Oliver Super 88. Yet they all had 540RPM PTOs. They didn't have PTO idjit lights either. So how do y'all think PTO RPM was set in those days?

 

[greg_g]

So how do y'all think PTO RPM was set in those days?

My experience with those ol' boys is limited to a JD-B, and an Oliver 88 (Standard I think). On them it was just a matter of pulling the throttle to the stops. But I don't recall either of them having over 30 drawbar horsepower, you needed to milk all the torque they could muster.

//greg//

 

[Soundguy]

I wasn't trying to nitpick.. I was just wondering if your tractor really got twice as loud without dropping half the rpm?

Just curious.. what tractor are we discussing.. and does yuor manual have an ergonomics section.. many do.. if so.. it may mention a spl in db that is observed at the operators platform, ( in an open area.. thus no side reflections ).. Just wondering what you's lists.

Mine's 89db at rated rpm. ( though i still use headphones so I can block out all the sound except for the classic rock coming thru the headphones.
I try to care for my hearing a little better than the 'average' joe...that means I wear hearing protection alot... even in areas that are osha safe levels.. Doing this.. I've found it is easier usually to wear good protection, vs avoiding the sound, when it comes to damage prevention.. etc.


Soundguy

It is a huge amount of reduction. Maybe it's 3 db...whatever cutting a sound pressure level in half amounts to, in decibels. Somebody else can look it up if they want. The bottom line is, at rated speed, I tend to use ear plugs and I don't enjoy wearing them. At 1800-1900, no earplugs needed or wanted.

There...are the flyspecks picked out of the pepper sufficiently now?

 

[Soundguy]

That's only beacuse 2 pages of posts pile dup before i had a chance to read. And since i read and reply serially.. .. all my posts get stacked on the end in a wad if I've been gone for any length of time..

A draw? This isn't a competition.. it's an 'opinion' volley ball match. With a few bits of (uninterpreted and sometimes vauge ) fact in the middle.

now where were we.. who's serve was it?

Soundguy

Wow! I think the summer heat is getting to everyone. I think we should call this one a draw. Hats off to Sound Guy - he hit us non-540 pto rpm guy's with four posts in a row. As a famous man once said "Get-R-Done!" (By the way, I mowed 5 hrs straight yesterday below 540 PTO rpm!)

 

[Soundguy]

Back when I was learning how to hand start a John Deere A, nothing had tachometers; at least nothing I ever operated. This included the Johnny Popper letter series; Farmall H, M, and C; and, my favorite, the mighty Oliver Super 88. Yet they all had 540RPM PTOs. They didn't have PTO idjit lights either. So how do y'all think PTO RPM was set in those days?

Hmm..

timing light?

Manual roller pto gauge?


Soundguy