wood chipper/shredder mod to increase chip size

[GeneV]

Guys, anybody done such a mod? I got a Dirty Hand Tools 3" chipper/shredder, but the chip size it makes are tiny, almost fit for compost. I'd live to increase chip size, make it more usable for mulching. Is there usually an adjustment for the anvils in there? I don't know much about the internal workings of these.

 

[5030]

Most anvils mount with a set of bed bolts and can be adjusted in and out. Normal setting for clearance is the thickness of a credit card (anvil to knife clearance) so you might want to check that. the closer the anvil is to the knife, the smaller chip is produced.

 

[s219]

Dedicated chippers usually have a gap adjustment for knives and anvil, but wider gaps take more power to make the cut, so you may find the chipper bogs down. Normally there is a spec for gap and you are supposed to set to that.

A unit with shredding capability will have a different type of cutting arrangement and may not be something you can change. They may use hammers and anvils. They are a different beast than a pure chipper. Normally you can’t tweak the output size of a shredder.

 

[GeneV]

Thanks for the info guys. Yeh it is a chipper/shredder, and it already does bog down when I stick a big branch in there. So I learned to not just jam it in.

 

[oosik]

I have a Wallenstein BX62S. It has a specific gap - knife blades to anvil. My chip size - half to one third the size of a playing card and about two times as thick as a playing card.

 

[bigtiller]

If you could purchase a screen for the shredder that has larger holes, it would increase the size of the chips. Or maybe you can remove the screen and drill some of the holes out larger.

 

[Captain Dirty]

As s219 pointed out wider gaps (for larger chips) take more power. With around 6 hp your chipper will be hard pressed to shave chips off the end of a 3" branch, especially if is a dried, slow growing hardwood (like apple or lilac). The operator's manual notes:

• Large, hard, dried tree branches that resist chipping can be processed by rotating them as you alternately insert and retract them. (Effectively reducing the diameter.)
• Material conditions vary, sometimes exceeding the capacity of the equipment. If the material to be chipped is extremely hard, kicks back forcefully when being fed into the chipper inlet, or cannot be easily controlled, remove
  the material immediately and set it aside. Do not attempt to process these materials.

Know and respect the limitations of the equipment you have. I am given to understand that Valby made or makes machines with easy to adjust chip size provisions costing on the order of 10X Dirty Hands.

 

[oosik]

If you have a screen on the chipper discharge chute - take it off. That should increase chip size. I would not recommend increasing the distance between the knife and anvil. It could put an excessive load on the chipper.

When I upgraded my tractor - I wanted to upgrade the chipper also. I had a Wallenstein BX42S. I looked at a Valby. They make some superior units. But the nearest dealer is in Montana. I went with my Wally BX62S and have had no regrets.

I even considered the Wally BX92S. Then I had a stroke of realism. It's all I can manage - drag a 25 to 30 foot long pine that is 6" on the butt. There is NO WAY I would have been able to drag a 32 to 35 foot pine that was 9" on the butt. Since I will fell 800 to 1100 small pines - I have no time to fool around with a system that is beyond my abilities.

My spring felling/chipping sessions usually last a month or more. Or until I get so beat up from dragging to a pile or falling that I simply quit. Finish off this annual project in the late fall.

Yes - falling down is, unfortunately, a part of thinning my stands. After I thin a stand of small pines - it looks like a giants game of Pick-Up-Sticks.

 

[5030]

Increasing the distance between the anvil and the knife won't impact the ability to chip or present an excessive strain on the chipper. It will however cause it to string chips if the gap is too wide.

 

[GeneV]

Hey guys, yeh thx. I don't see a screen in the discharge, no. This chipper does start to bog down if I force feed it 3" branches, but I'm wise to it's tricks at this point so just pull back on the branch and let it recover. I figure if increasing knife/anvil gap makes that issue slightly worse, it's fine, I could deal.

BUT, 5030 you bring an interesting point about that possibly making wood strings instead of chips, I see what you mean there. Then again, if S219 is right and there's nothing I could adjust in there anyways coz it's a chipper/shredder, well that's the end of that idea anyways. I'll just have to tear in there and see what's up, I'll report back if there's any progress.