Shredder DIY

[Erie Fred]

Shan't be cutting stones.
Not intentionally..............

Many times sticks have dirt on them.
You'll note the style of shredder you copying has slow moving rotors that aren't bothered so much by rocks, steel etc.

 

[Screwdriver]

I'll watch with interest but unless it's a paper shredder, I fear any sideways force at all and those blades will eat each other in a heartbeat.

 

[prepman]

Many times sticks have dirt on them.
You'll note the style of shredder you copying has slow moving rotors that aren't bothered so much by rocks, steel etc.

The commercial garden shredders that I've had, a Bosch and Hyundai wouldn't fare well either. The Bosch used a corkscrew chopper and the Hyundai uses a series of chopping blades arrange as vanes. I'll put a sign on in it ' NO STONES'

 

[prepman]

I'll watch with interest but unless it's a paper shredder, I fear any sideways force at all and those blades will eat each other in a heartbeat.

There is one thing to bear in mind is that the blades turn in the same direction not opposing. But side play will have to be limited. The spacing discs will be greater than the tooth width, by how much neds to be decided. Remember they all laughed about the Earth being flat once?

 

[prepman]

The spacing disc will be the costliest component, cut from solid bar? Cut from plate? Cut tube and spoked? x20 whichever. Commercially
available? Plastic?
Wider and larger diameter spacing changes dynamics. This would cut it into strips so not a fix. So a secondary cutter? Angled-Side feed?

 

[8ob]

Getting confused here, is this to be a high speed shredder or a low speed high torque ripper/crusher?

Bob

 

[dieselsamurai]

Getting confused here, is this to be a high speed shredder or a low speed high torque ripper/crusher?

Bob

I think to make sawdust as he requires will need to run faster than PTO speed but have some form of feed roller system

 

[oldbikedavey]

Had a fair amount to do with a Morbark trailed chipper, and the single blade is about 9" wide by about 3/4" thick HSS, mounted on a drum that probably weighs about 300 lbs.
Adjusting the blade to anvil gap is a pest, as it has to draw in air as well as branches via the hydraulic feed roller.
Part of the action is simple slicing across the grain, but part of it is also fracturing along the grain as well.
Uses a 22hp V-twin Kohler engine.....

 

[prepman]

Getting confused here, is this to be a high speed shredder or a low speed high torque ripper/crusher?

Bob

Still high speed but coarser cut.

 

[prepman]

Had a fair amount to do with a Morbark trailed chipper, and the single blade is about 9" wide by about 3/4" thick HSS, mounted on a drum that probably weighs about 300 lbs.
Adjusting the blade to anvil gap is a pest, as it has to draw in air as well as branches via the hydraulic feed roller.
Part of the action is simple slicing across the grain, but part of it is also fracturing along the grain as well.
Uses a 22hp V-twin Kohler engine.....

But obviously intended for branches > 4" ?

 

[prepman]

The thinking behind the idea is that most of the chippers rely on brute force on 1 contact point using a slicing action. My approach is to try to acheive the 'same' effect taking smaller faster cuts. At no point can I say that I know this will work. But it'll be interesting to find out. The spacers are my main concern. Also if the <4 " branch is fed directly in it will produce long pieces (basket weaving), so it needs to be angled to cut diagonally through the bough. The pinching action will try to pull the branch in and the spacers will counteract it. Similar to chainsaw teeth depth setters. Might well end up as an unfinished project, and me paying a couple of grand for a ready made? It isn't mainly about saving money although that's nice.

 

[prepman]

I've got 16ft wide Y flail mower. I could lay them on the ground and just run over them?

 

[pedrobedro]

I've got 16ft wide Y flail mower. I could lay them on the ground and just run over them?

Then you have the job of tidying up after

 

[gaz1]

turn a hand planner upside down and try that method

a shallac planner would also give the same method but with smaller teeth instead of a blade

 

[Farside]

"Welsh Man Eaten By Rogue Garden Machine."

 

[gaz1]

there is a youtube video and build

 

[prepman]

there is a youtube video and build

Hmmmm...not exactly....

 

[Kram]

It would be much simpler with only one set of blades. I'd suggest without spacers and just have the teeth staggered to make a drum without any gaps.

The tooth size will give you the width of chip. Length of chip will be the circumferential distance that the tooth is in the wood until it crosses grain and chips early.
Chip thickness depends on the disc rakers/clearance behind the tooth and how hard you feed the wood.

I may have to make one as a chainsaw attachment.

 

[Erie Fred]

I may have to make one as a chainsaw attachment.

They make something similar:

https://www.baileysonline.com/chainsaws/chainsaw-attachments/chainsaw-debarkers.html

I have seen somewhere one with segmented blades as you suggest.

 

[Kram]

Yes seen those dislike the idea of using a chain and bar to drive it... Thinking more like this with a belt drive

https://www.amazon.co.uk/Debarker-debarking-machine-Mounting-Stihl/dp/B06X3YJPJF/

And without a guard it could do small stumps with it.

Another option is to get a 60-80mm dia thick tube and cut a helical 1.3mm groove in it and wrap a chain with a screw clamp on the ends.