A Wood Chipper From First Principles

For whatever reason, certain pieces of technology can have a difficult time interacting with the physical world. Anyone who has ever used a printer or copier can attest to this, as can anyone whose robot vacuum failed to detect certain types of non-vacuumable waste in their path, making a simple problem much worse. Farm equipment often falls into this category as well, where often complex machinery needs an inordinate amount of maintenance and repair just to operate normally. Wood chippers specifically seem to always get jammed or not work at all, so [Homemade Inventions] took a shot at building one on their own.

To build this screw-based wood chipper, the first thing to fabricate is the screw mechanism itself. A number of circles of thick steel were cut out and then shaped into pieces resembling large lock washers. These were then installed on a shaft and welded end-to-end, creating the helical screw mechanism. With the “threads” of the screw sharpened it is placed into a cylinder with a port cut out to feed the wood into. Powering the screw is a 3 kW electric motor paired with a custom 7:1 gearbox, spinning the screw at around 200 rpm. With that, [Homemade Inventions] has been able to easily chip branches up to 5 centimeters thick, and theorizes that it could chip branches even thicker than that.

Of course, wood chippers are among the more dangerous tools that are easily available to anyone with enough money to buy one or enough skill to build one, along with chainsaws, angle grinders, and table saws, so make sure to take appropriate safety precautions when using or building any of these things. Of course, knowing the dangers of these tools have led to people attempting to make safer versions like this self-propelled chainsaw mill or the semi-controversial table saw safety standard.

Thanks to [Keith] for the tip!

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No Need To Buy A Woodchipper – Build One!

Polish YouTuber WorkshopFromScratch finally got fed up with tripping over piles of garden detritus and decided to have a go at building a woodchipper (Video, embedded below). Since they had a ‘small’ 1.5kW gearmotor just lying idle (as you do) it was an obvious fit for a machine that needs torque rather than supersonic speed. The video is a fabulous 20-minute journey through the workshop showing just about every conceivable metalworking tool being used at some point.

Checkout out the thickness of my blades!

One interesting point is the bottom roller, which sits between a pair of removable guides, which should help the thing self-feed without jamming. Whether that was necessary is not for us to judge, but it can’t hurt. The frame looks like it was constructed from at least 1/4″ thick steel, which is expensive if you don’t happen to have a supply to hand. There’s lots to see, everything from thin sheet metalworking, which was plasma cut, constructing the feed and exhaust guides, to box sections being skilfully welded at some interesting angles to make a cart to move the thing. They tell us the blades were constructed from some seriously thick slabs of C45 grade steel, but currently are not hardened. This is planned for the future, but we suspect not something that is easily achieved in the home workshop!

If this channel is familiar, then you might remember the earlier stump grinder they built. If you are drowning in sawdust, but have a log burner, then you’ll appreciate this sawdust briquette machine.

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