Chipper What happens if I hook up too much HP to a Woodland Mills Chipper?

[JethroB]

I was going to let this go but I can't help myself.

The question isn't if that scenario will take weight off the front axle, it's when will it take weight off the front axle and when will it add weight to the front axle? Use your scenario but add an additional 20,000 lbs. to the bucket. The fulcrum just changed from the back axle to the front axle and your 10,000 lbs. on the back added to the weight now on the front axle. But we all know it is absurd to think anyone would ever actually put any amount of load in the bucket of their tractor.

Back to your regularly scheduled program.

Interesting counterpoint and example. The weight is going ‘somewhere’. Thankfully the engineers are ahead of us with the hydraulic relief valve.

 

[Reb954]

I'm glad to see folks have a sense of humor.

 

[5030]

Before I sold it (for what I paid for it), I ran one of those Chinese chipper on the back of my M9000 Kubota which is 82 PTO horses and the chipper was rated for 30 PTO input maximum. I just added a Weasler slip clutch to the chipper input and set it to slip at a moderate input. 3 years and never an issue. I did have to add extension legs to the chipper body as it sat too low for the M9's output stub as it was built for a compact tractor.

 

[CoyPatton]

That really isn't true...

The smaller hp tractor most times will slow down a bit before shearing a pin. Many times it gets through the rough spot before the pin shears.

With the much higher hp tractor, for the same size shear pin, is has to much hp on tap, it shears the pin much faster and you go through more pins.

I've seen this happen many times...

SR

Agreed, while there is some truth to the shear pin protection from HP, I expect that you will shear pins frequently with near double the HP.
As for running at a lower RPM, you certainly can, but unless the tractor is equipped with an economy PTO feature, you will not obtain 540 RPM PTO speed. You may be fine with not being there but then again you may not!
You are in the position that you can play to see if it will work at an acceptable performance level and only lose the cost of some shear pins. If that is ok try it, but also start shopping for a chipper in the HP rated area of your new tractor. That way the decision making on purchase is at least jump started.

 

[Steelkilt]

Thanks everyone for the great information. I looked on the Woodland Mills website for shear pins as it seems I will need some for this experiment. Surprisingly, I did not see any available for sale. It was already after hours so I left an email. My 50hp tractor already burned one pin so I am on the last supplied of the two that came with the chipper. I'll find the WC68 manual tomorrow and look at the remaining pin in the PTO shaft to try and figure out what size is needed.

 

[Citydude]

With the hydraulic drive feed rate, I wouldn’t be concerned about the HP at all.

 

[oosik]

Regarding shear pins/bolts. Some chippers, like my Wallenstein, recommend use of Wallenstein shear bolts only. It's a specially designed bolt with a grove cut round it. This is where the bolt will shear. Some will specify their own bolts or an equivalent grade machine bolt.

By far - the equivalent grade machine bolt will be MUCH less expensive. The special Wally shear bolts are around $6.75 - as I remember.

If you are going to be snapping many shear bolts - it could be worth your while researching this.

 

[Egon]

Agreed, but the post I was quoting was so general, it just needed to be corrected.

Using a chipper, other than when first starting out, a bigger hp tractor shouldn't be a problem. You just have to be carful not to engage the pto too forcefully.

SR

Nothing vague about the post. When the shear pins rating is exceeded it breaks. It really doesn稚 matter what the HP is.

 

[CobyRupert]

The question becomes: Does the sheer bolt protect the equipment or the tractor’s PTO?
Using the extreme examples: 10,000 hp on a 10hp (rated) chipper, one hopes the bolt is sized for the 10hp chipper. (It should be).
The opposite is probably a problem: A shear bolt for a 10,000hp chipper won’t protect the PTO for a 10 hp tractor when it comes to an instant stop. Hopefully the PTO is rated to take the full stall shock load of the engine.
IMHO running a 20hp rated chipper on a 100hp tractor is better than running a 100hp chipper on a 20 hp tractor/PTO.

 

[k0ua]

The question becomes: Does the sheer bolt protect the equipment or the tractor’s PTO?
Using the extreme examples: 10,000 hp on a 10hp (rated) chipper, one hopes the bolt is sized for the 10hp chipper. (It should be).
The opposite is probably a problem: A shear bolt for a 10,000hp chipper won’t protect the PTO for a 10 hp tractor when it comes to an instant stop. Hopefully the PTO is rated to take the full stall shock load of the engine.
IMHO running a 20hp rated chipper on a 100hp tractor is better than running a 100hp chipper on a 20 hp tractor/PTO.

You bring up some very good points.

 

[jonsstihl]

again it is those extremes making it easier to visualise.

 

[Tractor Time with Tim]

Sounds like opportunity for a test video.........for TTWT......

have you checked in here lately Tim....????...

Hey YLee! I search for TTWT periodically.


To answer the question, it really isn’t a good idea to use too much tractor on a PTO implement. The shaft itself has a HP rating. Of course, a shear bolt or slip clutch can help, but most slip clutches are set too tight to really help, and when they slip repeatedly, folks will tighten them. Same thing for a shear bolt. The temptation is high to use a harder bolt to allow more power to the machine.

Having said all of that, if the user is careful, I’m sure he can get by without issue.

Tim

 

[justman777]

An end to the argument. Instead of using a chipper, just go with the more economical route of burning whatever it is you were chipping. Problem solved! :laughing:

Seriously, I'd love to have a chipper, but my finance committee says I have too many toys already. I'm like "Whaaaaaaaaattttt????"

 

[Sawyer Rob]

Nothing vague about the post. When the shear pins rating is exceeded it breaks. It really doesn稚 matter what the HP is.

I never used the word "vague"...

SR

 

[Egon]

I never used the word "vague"...

SR

So, General !

 

[workinonit]

Nothing.

 

[PEJ5]

Before I sold it (for what I paid for it), I ran one of those Chinese chipper on the back of my M9000 Kubota which is 82 PTO horses and the chipper was rated for 30 PTO input maximum. I just added a Weasler slip clutch to the chipper input and set it to slip at a moderate input. 3 years and never an issue. I did have to add extension legs to the chipper body as it sat too low for the M9's output stub as it was built for a compact tractor.

Steelkilt. This is one thing to consider...the angle of the PTO shaft joints. My snowblower manual contains a chart showing PTO shaft life relative to angle. You may need to modify the chipper base to sit higher. Love my WC-68.

 

[4570Man]

I often use the 10,000 pounds of ballast weight on the 3 point when I am trying to demonstrate to an "unbeliever" that putting weight on the 3pt. REALLY DOES unload and take weight off of the front axle. This concept will still be debated by some people that cannot wrap their head around the concept that a tractor is a teeter totter with two fulcrum points. The front axle and the rear axle.

So put 10,000 pounds of weight behind the rear axle and tell me the front axle won't lift skyward. But if you just put a 1000 pounds out back, many will erroneously debate that it doesn't remove even a pound of pressure on the front axle. They cannot see it, but the 10,000 pound example will usually get them to thinking. Another absurd example is to put a 100 foot boom pole on the 3 point and then put 100 pounds of weight at the end of the 100 foot boom pole. Think about that one for a bit. Yes, using absurdity to explain the logical, can work to enlighten.

That’s a lopsided argument. The backhoe on my M59 is the heaviest reasonable ballast you’d come across and heavier than most. If I remove the backhoe and attempt to lift a load the hydraulics easily just flips the tractor. The entire weight is riding on the front axle but it’s a lot less than with the backhoe. If I put the backhoe back on it definitely lightens the front axle load by a lot. Enough so that it’s prone to sliding sideways without additional front load. The hydraulics aren’t strong enough to straight up lift the back end up like that but it’s close. Now you’ve got a 10,000 pound machine plus the 4000 pound load riding on the front axle where it was probably only half that much in the previous test. Point being that for 3 point ballast to actually “save” the front axle it would take a ridiculous amount of it. Now if you claimed it helped the front axle by increasing the traction on the back axle you’d have a good point. With the backhoe on the M59 I can usually work on 2wd. With the backhoe off it’s useless in 2wd. My L3800 can still tip itself forward with loaded tires and a 500 pound BB. So that’s not enough ballast to help the axel. The point that’s a often overlooked in these ballast arguments is yes the ballast removes weight from the front axle while measured with light load on the FEL but any amount of ballast short of a ridiculous amount is going to significantly increase the front axel loading potential.

 

[k0ua]

If you would put about 1100 lbs on the 3 pt then you would not be able to tilt the tractor forward no matter how much weight you put in the bucket. Your 500 lbs and loaded tires is not near enough for that sized tractor. Even if you put 100, 000 lbs (probably need gold or platinum here) in the bucket your tractor would not tip forward because the relief valve would open and you would never get the bucket off of the ground. Same thing as hooking the lip of your bucket under a rock down low, your tractor cannot raise the rears because you have proper ballast on the 3pt and the relief valve opens. You have proved to yourself that your rear ballast is inadequate to the task of keeping the rear tires on the ground. If your tractor raised the rears in any situation of front end loading, then by definition your don't have enough rear ballast.

 

[DieselBound]

And THE answer IS: "Here, hold my beer!" :laughing:

If one puts 20 amps to an electrical circuit protected by a 10 amp fuse vs putting 40 amps to an electrical circuit protected by a 10 amp fuse, and?