Chipper knife sharpening for dry wood?

[CalG]

I've got quite a pile of fallen tree limbs collected over a couple of years. Mostly maple, but some Hemlock.

I'm in the processes of freshening the MacKissick chipper/ shredder, and anticipate going after that pile of dry and rotted stuff.

Should The chipper knives be reconfigured?

 

[oosik]

Give it a try - see how it works. That will be the ultimate answer.

 

[jeff9366]

No.

Chipping totally dry wood causes the blades to get very hot. Hot blades dull considerably faster than cool blades. Try to chip when material is green or half dry.

It requires considerably more PTO power to chip desiccated woody material than moist or semi-moist material.

I had a Wallenstein chipper for five years. I finally sold the chipper, returned to burning debris and buying mulch when I need it. I think buying mulch by the pickup truck + trailer load is cheaper than chipping branches.

You may find otherwise.

Those most happy with chippers long term are chipping material of a uniform hardness. (Christmas tree farms, vineyards ). Then the blades can be set for optimum chip thickness = thicker for soft woods (faster chipping, fewer heat producing cuts), thinner for moist hard woods (so chipper only slows moderately under load).

 

[oosik]

Jeff is undoubtedly correct. Dry wood will cause chipper blades to get hotter. There was a time - I let my thinned pines dry for a year before chipping. A program to reduce juicy sap buildup in the chipper chute. It worked very well. I never noticed anything heating up when chipping the dryer pines. Probably because they were really just somewhat dryer and not totally bone dry.

I've had two chippers - both were Wallenstein. An excellent piece of equipment. I now run a BX62S on my Kubota M6040. It does exceptionally well on green Ponderosa pines.

 

[tomplum]

I have a McKissick tow behind model. On mine the manual gives a clearance setting for better chipping. Too much gives more vibration.

 

[jeff9366]

I had a Wallenstein chipper for five years. I finally sold the chipper, returned to burning debris and buying mulch when I need it. I think buying mulch by the pickup truck + trailer load is cheaper than chipping branches.

What I really miss from my chipping experience is pulling forty to fifty foot long vitus-rotundfolia (wild) grape vines out of Florida trees using my tractor, then feeding one end of the vine into the chipper, then, standing well back, watching the vine change into thirty pounds of chips before me, without touching the vine.

 

[MAX-24-Dean]

I have a MacKissick chipper-shredder and went through trial and error to come up with what @jeff9366 posted.
With deciduous trees I now pile them in my garden and cover them with dirt and compost and let them improve the soil. Then use the moisture holding ability of the wood to help with growing melons and other edibles.

The larger diameter limbs get burnt, I then use the char mixed with the dirt to put on the garden.

 

[oldballs]

I've run a MacKissic tow behind model SC1650 for the past 15 years. Most of the feed is wind blown limbs of Sycamore, Soft Maple and various garden cuttings. I've never set the chipping blade to anything but the OE manual spec...with an occasional hand touch up....In fact , I don't think the blade is adjustable.....just the "Wear Plate". And I am on the last edge of the shredding hammers.....just as I am on my last edge of my ability to do these things.

The Woodland Mills WC68 Chipper is used for larger projects, usually of a single species. Even there, I set the "Bed Plate" to the OE specification. I guess one could vary it (Bed Plate) a bit depending on the species and the condition (wetness/dryness) of the wood. This Chipper is powered by either of my Kubota "B" models ((19 PTO HP)...The variable infeed rate is set half way i.e. @ "5".

That's my experience.

Cheers,
Mike

The OP asked "should the chipper knives be reconfigured" As I understand it, there is only one knife on that Mac....and it is not adjustable and the grinding angle is set at 45 deg.....just the "wear plate" is adjustable due to wear.

 

[5030]

I have a good deal in as much as I sharpen commercial chipper knives (which are through hardened tool steel) as well as grind chainsaw loops for all my arborist customers (saw loops have gotten quite expensive today, like everything else). We have a large woodlot behind the house and I am always fiddling in there getting rid of deadfall and trimming and my SOP is a match, some dry paper and a pile. If it's damp green wood, I usually have at least one commercial chipper sitting in the yard so I just 'borrow' it for a short and make chips.

 

[CalG]

I've run a MacKissic tow behind model SC1650 for the past 15 years. Most of the feed is wind blown limbs of Sycamore, Soft Maple and various garden cuttings. I've never set the chipping blade to anything but the OE manual spec...with an occasional hand touch up....In fact , I don't think the blade is adjustable.....just the "Wear Plate". And I am on the last edge of the shredding hammers.....just as I am on my last edge of my ability to do these things.

The Woodland Mills WC68 Chipper is used for larger projects, usually of a single species. Even there, I set the "Bed Plate" to the OE specification. I guess one could vary it (Bed Plate) a bit depending on the species and the condition (wetness/dryness) of the wood. This Chipper is powered by either of my Kubota "B" models ((19 PTO HP)...The variable infeed rate is set half way i.e. @ "5".

That's my experience.

Cheers,
Mike

The OP asked "should the chipper knives be reconfigured" As I understand it, there is only one knife on that Mac....and it is not adjustable and the grinding angle is set at 45 deg.....just the "wear plate" is adjustable due to wear.

I've got the 3 point hitch MacKissic chipper shredder.
It has two Knives, which I sharpen from time to time as needed.
I just flipped the shredder flails last week. Whoa! I forget how aggressive those things can be.

There is only one adjustment that can be made to the chipper unit, and that is the blade to anvil clearance. "Pass a dime, stop a nickel" .

Reconfiguration would be blade cutting edge angle. Just as in wood working edge tools, there are alternate bevel angles for different hardwood/softwood applications. In regards to chippers, I have not run across recomended bevel angles for dry or green material. There is not much I can do to "regreen" the pile out back, but with the invasion of asian jumping worms, I am needing every bit of mulch material I can produce.

In reality, It's not practical to remove a lot of knife material to obtain some specific bevel angle from that which is already there. but.. one can work in the desired direction ...

Sort of like lawn mower blades (I changed four today)
Some folks try to maintain a "proper bevel" but no one can rightly say what that is.

Factory knows best.....right?