PTO chippers RPM

[mellotango]

Hi,

I've been doing months of research, and am quite set on getting a pto chipper. I see the pros of pairing it with a tractor for its multi-versatility, since the tractor would not only be able to power the pto chipper for chiipping, but also be able to do loading (with front end loader attached), log crane attachment at back of tractor, and the capability to tow cargo loads of tree trunks to a certain spot before chipping. I've been speaking to my dealer, but they have highlighted a fact to me that pto chippers can only handle max 1000 rpms on the pto shaft, hence chipping output will be lower in comparison to common built-in engine driven wood chippers, which can achieve rpm over 2000-3000 rpms. I was planning to get a trailer hitched 15" pto chipper to be powered by a 150 hp tractor. In light of their comments, is there a truth in that only a max 1000 rpm by pto shaft will reduce the output or performance compared to an engine that comes built in with a chipper?

Thx in advance for your feedbacks.

[OneWithWood]

Welcome, mellotango!
My PTO chipper is designed to run at 540rpm which is the output of my 50hp tractor.  Does a good job but you can't push it.

[beenthere]

Welcome to the Forestry Forum.

Some chippers don't get belted up from the 540 PTO rpm, and there is a noticable difference in clearing chips. More cleaning out plugs from over pushing it.
I suspect the dealer is trying to get you the best combination, as he's heard the frustrations from others already.

[tgalbraith]

540 has always  been the standard PTO speed, but the newer tractors come with a second shaft (different spline too) that is
1000 rpm.   

[jdonovan]

I've been speaking to my dealer, but they have highlighted a fact to me that pto chippers can only handle max 1000 rpms on the pto shaft, hence chipping output will be lower in comparison to common built-in engine driven wood chippers, which can achieve rpm over 2000-3000 rpms.

is there a truth in that only a max 1000 rpm by pto shaft will reduce the output or performance compared to an engine that comes built in with a chipper?

I have and run a PTO chipper. It has a belt & pulley to get the chipper disk up to the right speed for chip clearing. If you got a 'cheaper' chipper and it ran the disk at 540, then yes, I could see it being a problem, but I doubt you'd find one rated for a 150 HP machine.

I've got a http://bearcatproducts.com/products/pto_machines/ch9540h/ its handled up to 9" material with out issue.

Unless you really had a need to turn saw logs into chips, or needed to chip VERY quickly, I'd think it would meet most farm-duty needs. Its rated for 60 HP, and I'm feeding it with 45. It takes 2-3 people to keep it fed.

I don't know what your needs are, but unless you were doing whole tree chipping, or running it commercially I would expect something like the 9540 will probably satisfy the general farm/land-owner need.

If you've got bigger needs than that, you're probably into a veemer, or one of the other trailer mounted 200+ HP machines.

[bill m]

I'm curious, who makes a trailer hitched 15" pto driven chipper?

[mellotango]

Thx for replies. I'm looking at a morbark beever m15r pto that is currenly the biggest pto on the market up to 15" logs. Not many people know this. It is just nice for old palm trunks that I intend to shred, whose average size is mainly around 12-14". So the entire trunk can go in at once without needing additional work to split the trunk into smaller size. See http://lifttruck.holtca.com/M12RM15RPTO.htm

I'm trying to compare it with an in-built engine model e.g. a bandit 15" chipper http://marriott-tree.com/product_showroom/Model_255XP.asp I can't seem to find out the output rate (in m3/hr), but it seems for pto and engine, their feed rates are both around 100ft/min. So am I right to assume the output rate is probably similiar, even though pto only revving at 1000 rpm, compared with the engine model of >2000 rpms? I am intending to get a used 160 hp tractor to pair the pto chipper with, which is higher than the max 150 hp tractor recommended. Will the extra hp count for anything? How does extra hp and rpm speed work together in relation to output capacity in this case?

[jdonovan]

I can't seem to find out the output rate (in m3/hr),

you likely won't. It depends far too much on the material being chipped. softwood brush, vs 12" hardwood poles, will have greatly differing feed, output, and volume.

their feed rates are both around 100ft/min. So am I right to assume the output rate is probably similiar,

yes.

pto only revving at 1000 rpm, compared with the engine model of >2000 rpms?

Get past the input RPM hang up. The manufacturer has designed the chipper disk to run at an appropriate rate and has gears/belts/pulleys etc.. to get to the right speed. Its not like they cut the 3600 RPM engine off the unit and just put a 540 RPM pto spline on and sell it as a PTO powered chipper.

I am intending to get a used 160 hp tractor to pair the pto chipper with, which is higher than the max 150 hp tractor recommended. Will the extra hp count for anything? How does extra hp and rpm speed work together in relation to output capacity in this case?

10 HP over I wouldn't sweat it. They seem to be rating the chipper for tractor HP, not PTO HP... So there is a range of machines that will match up. Not all 150 HP tractors are exactly the same at the PTO. What they are suggesting is that a 175, or 200 HP machine would have the ability to over power the unit, and may overwhelm the cutters, belts, gears, clutches etc...

[bill m]

I see from their web site the Morbark is a drum chipper. I have many hours on both drum and disk chippers and from my experience the drum chippers don't do as well with a steady diet of large diameter wood. Size for size it takes more hp to run a drum chipper verse a disk one.

[240b]

 My experience with chippers both brush and whole tree is at all about the HP. 12" is a pretty good stick of wood I don't know how dense palm is but I'd think it will be pretty slow going with a rig that size. Plus if the chipper is work at its limits its going to be stop and go with the feed rolls and the the tractor reving up and down.. I've found you need about twice the capacity chipper than the material you want put in it.. (12"wood= 24" chipper) I chipped a couple hundred tons of pine pulp with a 600-700 hp morbark and it was slow.  The feed was stop and go the whole time. the material was 10" un under....  I'd find one of these

 

[Knocker of rocks]

Your dealer is all messed up.  A properly set up chipper will run correctly for the PTO RPM it is designed for.  Most tractors run 540 RPM, and less run 1,000 RPM, but 1,000 RPM is more common with higher HP.   The chipper will have a clutch and transmission to get the disk to its design RPM.

You should look a new dealer. 

Buy a chipper to match your tractor.  And you won't need an economy PTO option on your tractor, you'll only need full RPM when you're running an impliment