Oversized tractor hp for pto chipper

[Mellotango]

Hi,

I'm thinking of obtaining a pto chipper model which can handle up to 15" trunk diameter. I intend to chip a lot of palm trunks with average diameter about 12" and they are supposedly "not easy" to chip. From the chipper specs, the unit is meant to be paired off with a 150 hp tractor. I've seen some good deals on tractors giving up to 180 hp. Is there going to be any problems with using an oversized tractor hp for a pto chipper, apart from increased fuel consumption? As I'm wondering whether more hp would help chip difficult palm trunks better.

And if this is possible, can I run the pto at 150hp for normal hardwood/softwood (hence less fuel consumption) and crank up to 180 hp for fibrous palm trunks?

 

[Piston]

I wouldn't think that would be a problem, however that's just my opinion. The real reason I'm posting is to ask you to PLEASE take some pictures and videos of that setup in action if you purchase it!

 

[ENG18LT]

Too much HP won't be a problem, just make sure the speeds match 540 or 1000?

 

[Gale Hawkins]

I agree 20% over is just fine. Not sure if fuel usage will be more for the 180 HP tractor in that the job may go faster if it does not bog as much.

 

[CliffordK]

Tractor RPM is all governed.
So, you can't really change from a 180 HP tractor to a 150 HP tractor. No dropping off cylinders like some of the new cars and pickups. But, really, the more HP demand, the more fuel that will be used.

Somewhere around 200 HP, tractors change from Cat 3 hitches to Cat 4 hitches, but since you'll likely be using a drawbar, that shouldn't affect you significantly. I believe the 540 RPM PTO shafts are standardized, although there are a couple of different sizes of 1000 RPM PTO shafts. But, you can adapt from one to another.

The risk and benefits.
A few extra horses may help keep the chipper running under a heavy load. But, it could put more stress on your equipment if you are constantly running at higher HP than the design spec, and if you clog it up, being 20% over spec could do more damage to the chipper.

That said, usually manufacturers post the "minimum" design specs, and not the "maximum".

 

[D7E]

150hp sounds small for a 15 inch chipper . When we rented a self propelled unit with a bunk it had a 300hp volvo just to run the chipper part and that died pretty good . If they claim 150hp as minimum be safe and put 200hp on it , Far less strain to have too much power running sweetly than too little power struggling and bogging down .

 

[tractchores]

It should be fine as long as the PTO RPM is at the right speed for the chipper. Many chippers have a sheer pin, belts or even a slip clutch to make sure too much force doesn't get put on either the tractor or the chipper if the chipper gets jammed. You will use more gas than a smaller machine. Given the larger machine I'd just double check that whatever protection mechanism is in place is working properly so that you don't destroy the chipper if you were to hit a rock or something

 

[Mellotango]

Here are the specs for the 15" pto Morbark Beever M12R & M15R PTO - Sacramento CA Lift Truck Catepillar Dealership It says 100 - 150 hp needed but I've been told by my dealer that putting up to 180 hp is ok, and the tougher type of palm trees I intend to chip will be faster, and the auto feed mechanism will need to kick in a bit less. I seen a used "good condition" 1995 Massey ferguson 178 hp going for a good deal. Any thoughts on this combo and do you think a near 20 yr old brand name tractor can still hold up?

 

[newbury]

I'm in awe of a 15" chipper! We need VIDEO!!

I just bought a Jinma 8" and thought that was big!

 

[CliffordK]

You're hanging 2 tons off the back of your 3-PT?
WHEW

Is this for accessing at home or a central base station, or on the road?
If you are moving around, I would think it would be easier to deal with a trailer mounted engine driven PTO that you would just pull behind your chip truck. Then it would leave your equipment free to fetch the trees.

You can sometimes find used combine engines or truck engines that are relatively cheap.

I like the 20" chipper with the grapple.
Morbark Beever M20R with Loader - Sacramento CA Lift Truck Catepillar Dealership

But I have no doubt that it isn't cheap.

It may be cheaper to buy and mount a large diesel combine engine & trailer than it would be to buy & maintain another tractor.