How Many pto speeds do I need?

[goodoleboy]

I looked at a Farm pro tractor that had selectable 540 pto and 1000 pto speed.
I looked at a big 3 brand and it only had one? Is the switchable pto an option?
Or do different implements run at different speeds?

 

[GRUMPA]

540 is the most widely used speed for implements. 1000 is used for specialty equipment that I myself will probably never use.Nor 99% of other folks for that matter.

 

[Robert_in_NY]

540 is the popular pto speed for tractors 60hp and under. However, the 540 pto shaft will shear on larger tractors which is why almost all larger tractors have 1000pto. In ag use 1000 pto speed implements is about all you find. 1000 is a stronger system all together but very few items use it in the small scale like 6 foot brush choppers and tillers. There was a thread about it with all the numbers about force and such and why the 1000 will hold up better then 540 but I don't remember the thread and don't feel like tracking it down. Maybe someone else will remember it or you can do a search for it. Take care.

 

[timb]

Torque=(hp*5252)/rpm.

From that it's not hard to see that if you need to run a certain amount of horsepower through any shaft - raising the rpm will cut down the torque force involved while still delivering the same hp.

When the twisting forces get too high at 540 rpm - going to a 1000 rpm system nearly cuts the twist in half at the same hp.

Now the PTO shaft is turning faster, so there has to be more gear reduction built into the implement to get back to the same tiller etc.,. shaft speed, but at least you've reduced the stress on the driveshaft connecting the tractor to the implement.

 

[Bob_Skurka]

I think Grumpa probably gave the most practical answer to your question.

I don't care a red cent about the theoretical issues or the physics involved in the 1000 rpm PTO speed. And to be honest, I don't care what implement speeds "real" farmers use on big tractors. What I care about is can I find implements to use with my small tractors.

Other than some imported used stuff on Ebay, I have never seen anything that fits a small tractor that runs at anything other than 540 PTO speed. I've looked at brochures from LandPride, Woods, Befco, King Kutter, Buher Farm King, New Holland, Kubota, Tractor Supply, Northern Tool, etc. None of them list any implements for sale for a CUT in anything other than 540.

I buy medium duty diesel trucks and one of the tricks that truck salesmen try to pull on me is to show me features that are nice in their big rigs. But as I don't buy those over the road trucks, the discussion is pointless. Seems like a 1000 pto speed on a CUT falls into that same category. Just becuase a real farmer needs it, doesn't mean it will help me in any way at all, and if it won't help me, then is it just something else that might break down?

I guess 1000 pto speed on a small CUT is sort of like **** on a bull; interesting to talk about, but not very practical. Now for the intersting observation, the Farm Pro & NorTrac tractors are sold by people who list the 1000 pto speed as a benefit, but they don't sell implements that run at that speed! So then what is the point? They sell you a tractor and say that a 2 speed PTO is better, but they don't even offer the implements to go with it. Sounds like the same trick the truck salesmen try to play. Personally, I'd rather deal with an honest salesman.

 

[PineRidge]

<font color="blue"> 540 is the most widely used speed for implements. 1000 is used for specialty equipment that I myself will probably never use.Nor 99% of other folks for that matter.
</font>

I agree with Grumpa. I have never even seen a 1000 RPM implement for cut use. They may be out there but they sure aren't plentiful. My last tractor had a 540/1000 RPM PTO speed but the higher PTO speed was never used it was a moot point.

 

[timb]

Well... someone asked for the mechanics behind the reason. /forums/images/graemlins/wink.gif

I agree though that a lot more useful if anything might be something in a 540 + 700-800 range. That way a bigger CUT might be able to run a normal implement in a light-duty mode at reduced engine rpm when you don't need all the power. Some of the bigger UT's offer something like that calling them 'economy PTOs' but haven't seen one on a CUT.

I have seen a couple of CUT-sized 'implements' that either take (generators) or 'benefit' from a 1000 rpm PTO, (a couple of chipper/shredders to get to prime cutter speed) but they're pretty rare - and there are plenty of more standard 540 rpm versions to choose from in any case.

I'd be more interested in how a particular tractor controls the PTO - (live independent or not?) and the 'clutch' - slam-on electric or electro/hydraulic or a mechancal control you can feather?

 

[Soundguy]

</font><font color="blue" class="small">( I have never even seen a 1000 RPM implement for cut use )</font>
]
Lots of the yanmar tractors have a 3 spd pto. 540, 768, and 1040.. all using the same shaft.

The yanmar specialty tiller uses the higher speeds. Also, the mid pto speed give you the option of running the engine at less than 'pto' speed.. but yet still getting correct pto rpm's on the implement. A spreader comes to mind.

Some of the larger tractors have a swapable pto shaft.. depending on what shaft is installed, is what pto speed you have.

Soundguy

 

[Robert_in_NY]

540 was designed back when tractors didn't have much power. Since then 1000 is a better system but there are all these items that are around designed for 540 so it is hard to change and tell people they need a new tractor to run a new brush chopper. Just because you don't use it doesn't mean it isn't a better system. A lot of hay equipment is 1000 pto and a lot is an option when ordering, you can order a 540 or 1000 setup depending on what your tractor is set up. I think just like 3pt hitches were standardized, all pto implements should be standardized. At least most of them are the same size for 540, they use to be different sized 540 shafts back in the 50's. But you are right, you have no use for it so it should not be a option on a tractor.

 

[Bob_Skurka]

Robert, just for clarifications sake, you are talking about tractors in larger size ranges are you not? More like the larger Utility Class machine and the implement that those, and larger, tractors operate?