Cody's Disc Chunker

I am finally making a chunker. Looking around at what I have and what I can buy, I am going for a Disc style chunker.

Bought a 12"x12"x1/4" plate at Lowes. Holy cow they lied about the listed price. It said 36 dollars, when I scanned it it said 49 dollars :scream:. Oh well.

I also bought a W Weasler Hub. I have a length of 1" keyed shaft I can use.

I have pillow block bearings out the wazoo, no problems there.

I am going to rob one of my wheels from the mini truck build, it will act as my flywheel and final gear reduction. First reduction will be chain driven. Essentially I have a 20" pulley as the final drive. I’m looking at a 10:1 alone on the final leg. Do you guys think a 10:1 will be enough? I don’t know if I should run the engine at 1800 rpm or 3600 rpm.

Also for the blade profile, I’ve seen many use the “shark fin” style, I have seen a few that use an entire circle but it is rotating oblong. CamKutter - YouTube

Of course Kristijan has built one before, Wood chunker, first run - YouTube

And Jonathan Collins, Wood chunker wood slicer - YouTube

And Bobmac has done one with his square baler gearbox if I recall correctly.

I’m not sure which is ideal. Any tips for drawing out the shark fin style? I’m bad with swirls, the Golden Ratio scares me :joy:


It looks like about 60-90 rpm from the video. I would have to actually time it.

inkscape is free. :slight_smile: Then, blow it up to the size you want, print it and use it as a pattern.


Any design will work but in my experiances, the shark fin style is inferior because the tip is the weak point. If you just round it up a bit and give it a bit more meat, then its better.

As for rpm, if the blade is big enaugh that you can cut out a big enaugh window to be able to push the wood in in time, l guess 180rpm will do, but you will need to be quite fast. 60 to 100rpm is probably on the money


Sounds good, I can add more gear reduction before the final drive, probably a 20:1 ratio just from looking around at what I have to work with. I’d like to be able to use a 6hp engine so I should aim for the highest ratio I can build.

You say the shark fin is the least desirable, do you think a plain disc rotating at an askew axis like this voided area being the rotational axis?

I was thinking along these lines but also just cutting out an egg shape, like a proper Cam Lobe. Have a tip with a rounded edge like you suggested. At least with an egg shaped blade I can sharpen both sides and turn the blade around before I have to take it to the shop and re-profile.


A hybrid. Instead of this

Do this

Eggs and round blades will ofcorse work but you want a gap to open as soon as the chunk is cut, to give you time to position your wood in for a next chop. Specialaly if having higher rpm.


Aha so more of a Bean shape, gotcha.


Bingo. Best of both worlds