Nice machine JO 
It’s something special fun with inventing wood processors 
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@JohanM @SteveUnruh @Woodrunner
Thanks!
Super rain today - busy watching the chunks waiting for better weather 
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Any chunker is better than no chunker but I think sheering, like a Rebak, is better as a rule vs slicing. Dragging a blade across the wood to create the cutting action might reduce the immediate forces and strain on the frame and what not, but the friction adds quite a burden on the motor.
My “head design” for a chunker would use a circular sheer blade - like a foot diameter of quarter or 3/8ths inch circular plate steel with a one sided cutting edge ground into the perimeter.
The circular sheer blade would be mounted at its center on crankshaft that would move it up and down a few inches, guillotine style. The flat side of the sheer edge moves past a flat on the downstroke which is how it would cut. The crank has a stroke of only a few inches but is driven by a large diameter pulley on the same shaft. This easily decreases RPM and increases torque. A four inch stroke vs a 12 inch pulley is already 3 to 1 mechanical advantage. A small drive pulley or sprocket on the motor that powers the sheer could get the system wide RPM down by a factor of 12 or so. You’d probably need an extra stage for a simple/cheap AC motor but it’s getting close (1800->60 RPM is 30 to 1).
The circular sheer blade is loosely bound to the crankshaft so it can rotate, stiffly even, as it cuts. In fact I would have the chute deliver the wood slightly out of center to the blade mount to encourage slight rotation as it cut and distribute blade wear.
The sheer would be easy to sharpen. Just chuck it in a drill press or whatever (AT SLOW SPEED) and use angle grinder as it rotates to freshen up the edge. The blade doesn’t need to be perfectly circular - just circular enough the edge plunges past the flat in all orientations. The flat side of the blade could be hardened to improve edge wear but now we are getting fancy.
Sorry I don’t have a diagram at the ready. I should draw something - it’s been living in my head for too long. And sorry for the wall of text for a chunker no one asked for. Ha!
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I am a big fan of JO’s new chunker. Way easier to build that any other I’ve seen and could actually be made by less skilled builders than his other Rebak which is admittedly a gem. The right angle gear box could be hard to find obtanium but with some bucks readily available at Surplus Center.Com.
What is the diameter of that blade JO? Also I can’t wrap my head around 4 and 5 hundred volts. Other than industrial everything here is 220.
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Where yours is 110 V, ours is 230 V. No two phase, only one or three. Three phase is 400 V between phases and 230 to zero.
Why did you make a hole JO, instead of using the outside?
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Anthony, I always build the opposite way - looking at what “free” material I have on hand and try find out what I can fabricate 
It’s extreemly rewarding when the hoarding pays off.
Tom, it’s a little over 21 inches.
What Joep said about voltage. Phase to neutral is 230V, but a domestic hookup over here is always 3-phase - unless you live in an apartment.
Joep, I wanted to maximize the force (closer to center) towards the end of the cut.
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Still have all your fingers and toes J-O? No obsessive thoughts? 
Does the new chunker live up to your expectations or would you have done anything differently?
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I counted to 10 of each a minute ago
I haven’t had the time to try it out much more after making the video. As I mentioned I will try play with anvil angles some to prevent jamming.
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I was thinking about other ways to take the flex out of that blade and thought about the lid band from a 55 gallon barrel. It a little larger in diameter than 21 inches but close enough that it should close up without kinking. I was going to dig one out and smash part of it flat to see it it would close up enough to swallow the width of a blade but got called away for dog walking and didn’t get back to it. May or may not be worth the effort but now I gotta know. 
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Tom, I’m not too worried about the blade flex, since the support bearings take up that force. But it wouldn’t hurt to have something solid at the perimeter for some flywheel action. Probably not worth it though, since it’s such low rpm. That’s the downside using an intergrated motor/gearbox like this - nowhere to attach a flywheel.
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You could put “idlers” on the perimeter of the blade wheel like bandsaw guides: little wheels / bearings that hold the blade straight up and down and keep it from flexing out of true.
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