Woodrunners wood processors

Woodrunner · February 18, 2025, 7:06pm

Thought i should start this thread for my various attempts to make wood handling easier.
I may also post some on my equipment i already use, if theres interest?

Anyhow, i start with my new project, a screw chunker.

What i start with are four discs of hardox steel, cut in a “spiral” increasing radius.

I may have underestimated the strenght of 6mm hardox, i had to fabricate a “bender machine” with some inspiration from youtube, and a 12ton bottle jack.

Well, it worked as supposed, but

I really underestimated the stiffnes of the steel, the heavy square tubing bended, if you look carefully.
And the disc returned to origin shape when i let it go…

So, some cuts, bending back to straight, and welding.

Then i put a very strong pipe inside the square, and a"lever", a “gauntlet screw” (translation?) to put some tension on it. Version 2.0

Went better, but not strong enough.

So, a pipe welded in, and a guide for the moving part.
Version 3.0…

When i pushed version 3.0 with a longer rod for the jack, it went skew, and jammed, so, another guide, and more welding. Version 4.0

Version 4.0 worked like a charm, lets call it succes

Now for some welding of the flight to the axle shaft, and bending “fine tuning”.

Bumpa · February 18, 2025, 8:12pm

Goran, only those of us that have made those flights for a screw chunker can fully appreciate how much work you went through. For you guys that haven’t, it is probably one of the most difficult things I have ever attempted. My hat goes off to you Goran for your persistence.

GC

Woodrunner · February 18, 2025, 9:05pm

Thank you Garry, im just back from shop, just a little looking, measuring, and test-fit of those flights, and i realized how much work there is left, to fine adjust the flights, tack them in place, and bend some

Tone · February 19, 2025, 9:03am

Goran, you are good and persistent, I know you will manage to build a good chipper, now that I have tested the chipper with rotating knives I can say that this screw chipper is much better for cutting unpruned branches. I would only emphasize that you have to be precise with the side adjustable plate, against which the screw blade rotates, and of course with the last screw thread, which must run tightly against the housing, here I would emphasize that it would be good if the last part of the screw thread (a few cm) ran in the groove (like the Wayne-Keith cutter) and would smoothly cut off the fine fibers and twigs.

Woodrunner · February 19, 2025, 10:43am

Thanks for good ideas Tone.
I’ve thought about making a “sacrificial” part out of some super hard teflon plastic i have, and let the end of the screw cut it’s own groove in it, just to get the best cutting/separation of the chunks and twigs.
And a good, adjustable plate, tightly spaced from the screw.
Now im into finding some heavy duty oversized bearings for the shaft.

Woodrunner · February 19, 2025, 10:50am

About the disc-press-bender thingy contraption, i forgot to mention:

It really makes sense which side the lifting and static pieces are placed, i guess my screw chunker became counter-clockwise rotating, not as planned, but i rather build a gearbox that reverses rotation, than rebuild the d*amn bending machine

JohanM · February 19, 2025, 1:54pm

Or use a three-phase motor, it seems to be the rule to have it spin the wrong way when using it for the first time no matter what so you have to switch two wires which ever way you connect it

Bumpa · February 19, 2025, 2:06pm

Yep, yep, yep Johan I can definitely attest to this.

GC

Tone · February 19, 2025, 2:27pm

Goran, if your screw chipper will cut wood up to 8 cm thick, it needs a torque on the shaft of approximately 500 Nm (50 kg/m). When choosing a drive motor and gear ratio, this is the basic guideline.

Woodrunner · February 19, 2025, 4:14pm

Thats the reason i bought a phase-check tool at a swap-meet, old as earth, but works good
If i only could find it…

Woodrunner · February 19, 2025, 4:20pm

Thats good info Tone, i plan to put a standard pto shaft on it, to see if Fergie will pull it.
Then i have a increasing speed gearbox for pto, that i plan to run backwards so it becomes a reducer, this has a belt pulley, so i plan to try a small Lombardini diesel i found cheap.

JO_Olsson · February 19, 2025, 5:21pm

The trick is to connect the wires and close the lid - then open it up and switch two wires right away

Albertasmaximus · February 20, 2025, 3:38am

Hardox will crack with out heat treatment its not like maliable steel

madflower69 · February 20, 2025, 6:10am

How did you arrive at this number? I am just curious. I haven’t ever seen a number put to it.

Tone · February 20, 2025, 8:11am

Hello Sean. You are right, manufacturers of screw cutters like mine, intended for tractor drive, only state the required tractor engine power. My screw cutter R8 (up to 8 cm thick) has a power of 20 kW at 500 rpm, if we try to calculate the torque from this data, it is 382 Nm. When using and observing the operation of this machine, I can say that it mostly operates with a much lower torque of about 200-300 Nm, but occasionally it cuts hard and knotty wood and then the drive torque exceeds 400 Nm.
The engine on my Feri with a working volume of 2.4 l has a torque of 149 Nm, the gear ratio of the engine to the cardan shaft is about 4 - 1, which means that it reaches 596 Nm of torque on the cardan shaft, occasionally even this is not enough if the wood is thick and hard

Woodrunner · February 20, 2025, 9:15am

Hi Craig, i will try without heat treatment, to see if it works, this Hardox is cold maliable, i got the data sheet for it. Class 500? Maybe? I try to find it.
Only thing is the welds lost some hard surface, but the edges is plasma cut, and hardox is known to work well with plasma, the fast cut, and oxide layer stops the heat spreading some.
Well, we know more after trying.

Tone · February 20, 2025, 10:48am

Goran, I have one request, can you take a photo of the bottom part of the wood cutting machine, where the blade for cutting cubes is,…

Thank you!

madflower69 · February 20, 2025, 10:53am

I think your tractor might have more power then you think. the DT4500 with the perkins diesel engine was rated at 44HP (32.8kw). You may have derated for woodgas. I appreciate the ballpark figure (rough estimation) though.

madflower69 · February 20, 2025, 11:42am

I was going to use GM wheel hub assembly for mine. Specifically these because one was starting to go bad, and I replace them in pairs. plus I wasn’t planning on running very fast. And they bolt in from one side which should make disassembly easier. I just realized I might need a cup of some sort to hold the bearing better. I need to figure out the frame yet and what obtanium I need.

Shop GM Parts - GM Genuine Parts & ACDelco?

Woodrunner · February 20, 2025, 6:36pm

Hi Tone, i post some pic’s tomorrow, or this weekend.