That looks good enough split up some big log slices, I would have a days worth of chunked wood in no time. The only bad about cutting up big logs into slices,it take a toll on big saws and chain saw blades, In some cases might be the best rought, Another way i might go is rig a big log pick up devise,and split up the log and then chunk as usual, Though i havent dealt with cutting big diameter logs much yet luckly. The rebak chunkers look like the best chunker,fast chunked wood for 2" average size tree limb or split wood.
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I had a video of the chipper in use but that is long lost. I just bought another vertical mill to replace my Bridgeport. I will be moving the chipper from where it has been in the shop for the past decade. 've been cleaning up in preparation for the move. I’ll get some pictures or a video of it explaining what I built.
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Here are some photos from building it. The screw was machined from a section of stamping press crankshaft that unfortunately was a bit low on carbon to be able to harden to the amount desired. I hard faced the cutting edge and then used a tool post grinder to grind the screw to a knife edge.
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The screw needed a means of driving it. I planned on driving it with a tractor power take off. This is the drive coupler that connects the screw to the power take off drive shaft.
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Excellent work, @ohlerron. Just one question about sizing. Isn’t it a bit too long? I would say that length equal to 1.6x diameter is enough for the purpose.
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It was my intention to feed sawmill slab wood into the chipper. These pieces of wood are easily upwards of 12" wide. I actually wanted to make a Laimet type but lacked the components for my universal mill to mill a conical screw.
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Here are more photos. I made a flange that was welded to a collar for the screw that prevented chips from exiting past the screw support bearing. I made an anvil or cutting die that fit tight to the screw. I made the flange slightly larger than the screw necessitating a step in the anvil. I made the anvil from thick tube and turned the step in the tube in a lathe. The length of tube I had was too short so I made the anvil from 2 strips welded together to make a longer strip. These were then formed to the correct radius in a press. I welded the formed anvil to angle iron with a steel bar welded in place to prevent the anvil from bending away from the screw under load. The anvil and the screw support bearings are able to be shimmed and the support bearings have adjustment bolts to be able to fit the screw tight to the anvil. In the photo of the drive coupling one can partly see the anvil bolted in place with counter sunk cap screws.
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Hydraulic ‘chunker’ I hadn’t seen before. Interesting blade design.
https://www.youtube.com/watch?v=0bK99Ne2JyI&list=FLNjlzx0mwrswMIqVHHAqrug&index=112
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I had started converting a 24" stroke Cincinnati metal working shaper to a splitter/chunker but the fire left it sitting outside and in my way. It joined the other 80,000lbs of burned machinery in the scrap container last year. They will cut a serious chip out of a block of steel so I figured one could work as a chunker. I still have a 24"x30" Gould and Eberhart shaper that I can convert.
I keep looking at one of the old lathes I have thinking they have possibilities as a rotary chunker.
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Does anyone have any experience with these shredders?
I was visiting a friend far away ( not so far as Jakob is used to travel) and he got this shredder. I think it is a perfect fuel for a drizzler or one pipe design. Anyone with real brains got anything to report?
He wants to make pellets but I think it is ready for gasification.
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I have seen videos of that type of shreder being used for wood and shells I think in India. They are typically used as garbage compactors, or metal shredders. They are typically quite pricey. That style is also used for shredding plastic so you can recycle the plastic. If you want something smaller but useful to see how they go together, the shredder pro is probably in the ballpark.
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found that one already and downloaded. Still a little high in price for the components.
The one my friend has comes from BMW scrapping steel.
I am thinking of pallets we have to get rid of and willow from the land. Plus plus. Cant get it out of my head now for a few months.
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yeah. I wouldn’t buy the components they (to me) seem extremely marked up, and parts of the design seem like they are intended to make it so you need a machine shop ie buy their parts to make. And of course metal costs always seem really high to me in general so there is some distortion there. Then the premium for being green.
I would stick with the basic design though. I will let you figure out fab with the tools you have available. You are good enough to mimic it. 
They actually make smaller ones for 3d printer recycling at home.
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Precious plastic is designed for plastic. It cant handle nails. A lot of try and error before is does, but I like the principle.
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The design of the cutters is the same. You may need hardened steel face plates for better cutting, more torque or overall beefed up. They have pretty hefty energy requirements.
There is another style that uses one or parallel augers then it is just a ring at the end for the cutter. It uses less overall energy to operate.
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Stupid A@$, couldnt resist, the flesh is weak. I was working nearby, two hours from home and decided not to drive again so I took it home with me
As soon as the boys saw the new toy they had to try it out 
. No work this evening.
8 mm strainer in it. Way to small. Almost sawdust
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I have owned and used a few twin shaft shredders and also the more modern single shaft shredders when i was recycling plastic years ago , one thing i will say though never ever use that shredder without the lid with the correct Hight it should be high enough not to be able to reach in to the bottom , but of course you know that .
Dave
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Yes, the boys started without of course. I was a little angry. When i was young i worked somewhere and saw a bended pole. How has that happened? Someone put his finger in and the machine started eating. He was found when his elbow was in and he leaned against the pole screaming like hell. Emergency brake saved the rest of him. Scary story, happened 35 years ago.
The good thing is, this one eats nails too.
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My dad has witnessed a lot of horrors in a machine shop. He ran a screw machine/lathe, and when he stepped away from his machine for lunch, someone took over and tossed in a rod but didn’t support it from the other end or shorten the rod like you’re meant to. It began to spin and the unsupported end began to crack like a whip and made this big industrial machine start to jump out of the concrete floor.
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8mm might work for plastic recycling. i think the plastic site with the shredder has plans for a couple types of plastic molding like lumber. Which maybe people would buy it from you, and you could cover the costs. We can’t use it in place of lumber in the US, but the EU may be different but it would probably be good for raised bed gardens and other projects.
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