Normans chunker v1

The wheels came off this morning, but it is working I guess. Definitely function over form for the time being. And if anyone else wants to use a generator motor to power a chunker, here is a quick trick to free up the gen head from the tapered crank shaft

13 Likes

I bet a slice off a leaf spring would hold up better for a cutting edge too, my 1971 nova back in late 70’s leaf spring main leaf broke, i plated it and welded back and it lasted over a year., before Sold the car or traded.I was surprised how well it welded and held to gether. Though it might need heating too get it too fit the cutting wheel shape.

3 Likes

Marcus, have you thought about automatic wood feeding, if you designed the knife like this, mounted the housing at a bit of an angle

5 Likes

Well Marcus just proves you’ve always needed more speed and power.
Anyhow good example of Use-it-Up. Wear-it-Out. Make-Do. Or, do-Without.
S.U.

7 Likes

Tone
I have thought about a auto feed feature, but I think I will leave that to the rebak later down the road when I have time
Steve
I am very surprised the difference i can feel in power going from the 6hp on propane to 8hp on dino. Definitely more low end grunt. I left the carb untouched it is exactly as it were on the generator and runs lower rpm im guessing 1800-2200 and has plenty of power to chunk semi dry doug fir of the 2×2" variety. When something larger comes along say 2x3" and knarled up pieces the rpm will ramp up, but not fast enough to power through a real nasty piece I did stall it out once. But it definitely does show as I susupexted I needed more power. Bonus even if this motor ends up being temporary, it is a cast iron sleeved industrial grade briggs. More betters me think

6 Likes

Good morning Marcus .

With more power you definitely could chunk faster but I think the key to avoiding stalls is more fly wheel .

9 Likes

Im not sure how much more I could add, i know the size of the piniin on this axle and if the day ever comes and she shears off at oh 500rpm tire and wheel and break drum and pinion flange your talking a deadly destructive force! I think to go much larger would warrent a heavier axle, something in the 1 and a half ton range for more pinion strength

7 Likes

Marcus, Mr. Wayne probably meant to add mass to the axis of the blade, here the mass does not burden the gears, on the contrary, it relieves the shock a lot. In addition to the blade, you have a rim without a tire installed, if it does not hinder the work too much, you could put on a tire and fill it with concrete, so you would get a lot of mass, probably 200 kg.

4 Likes

I was thinking the same thing… i cant remeber off the top of my head what kind of clearance there was. But a second flywheel would add more mass.

Tire breaking free might never happen… but some sort of cage/gaurd around spinning objects are never a bad idea… probably wouldnt be my first priority when fabricating… and i should take my own advice, dads chunker doesnt have anything around flywheel either.

3 Likes

If that tire will hold water I’d fill it, making sure there was no slosh. Not much to lose if it didn’t help. Just have to empty it. Of course you would have to tap some kind of fill port in at the edge of the treads.

2 Likes

He could fill at the valve stem, poke a hole in the top and when all the air is bled out use a tire patch plug.

A gallon of water weighs 8lbs so figure that math out.

2 Likes

Kevin,
I cant quite visualize everything you said. But I know some people make very good machetes out of old leaf springs. It should make a good cutter. Any chance you could make us a sketch or just tell us more about how to do this?
Rindert

1 Like

I like the simplicity of filling the tire with water but I don’t think that will work all that well. The rotating mass of water will just continue spinning inside the tire even if the rim and tire stalls on a tough piece of wood.

Concrete would work better than water and even then the concrete should be anchored to the rim somehow. That’s a bigger project for sure but worth it because I agree that flywheel is key to avoiding stall.

The instantaneous “power” of that spinning mass is very effective in muscling through a chunk. But it can only deliver that instantaneous power if the spinning mass is coupled to the shaft effectively. The forces on the flywheel are going to be huge in the moment and that force will find the weakest structural link every time. The weakest part better still be plenty strong.

6 Likes

Iv a feeling the weak part woukd either be the pinion, its pretty small diameter and I have seen dana 60 pinions break under hard load, but what im still shocked at being that I welded the diff solid, is if the right chunk comes along and really puts the beans to the whole system I can watched the cutter head momentarily stop. Like there is no motion whatsoever, but that pinion and flywheel are just given er all the way. The only thing that could be happening is the axle itself has gone full torque and is winding up like a jack in the box kids toy and getting ready to leave the chat at a high rate of speed inside the axle housing. This happens several times in a chunking session, and its a little scary to think about a 1 and 1/8" axle shaft spun up in there just begging to let go. But that being said after another 2 hours running it last night and rubbing the fuel line through on the exhaust (no big deal it didnt even catch on fire :laughing:) I found that it will cruize through pine 2x4 material, even a couple 2x6 pine boards with ease! She didnt like the doug fir 2x6 and ill admit I was pushing it pretty hard to test if she would go. That is a huge time saver not having to split the 2x4 material before chunking which I get a lot of that stuff in the pallet pile 2 and 4 foot pieces.
Thats half the time spent chunking is splitting before chunking, so thats a drastic improvement for an extra 2hp. And for about maybe 3 and a half hours runtime I used about a gallon and a half of dino juice. About 8$ in gasoline, to produce the equivalent of 900-1000$ of what woukd be gasoline cost in the truck. Very rough numbers but lets even figure in my wages, I charge 25$ an hour on side jobs for my time. 75$ my labor, 8$ in material. 10:1 cost savings and a smile as I pass the gas station you just cant beat that! So there is another full load on the back of the dodge that will go in the drying bin come morning break time. Its pumping out the fuel and everything I had at the house is all chunked up, should be give or take a few days about a month worth of fuel put up. Brought home about another 60 feed bags from my dads last night to hold most of it once it dries down

8 Likes

I thought that was why they invented jello, Anthony. :stuck_out_tongue_winking_eye: :grinning:

This log splitter I have is a Champion. I split about three hours the other day and I don’t think it used a quart of gas.

8 Likes

Hey Marcus,
To prove the benefit having more carry-through mass at the cutter head you could temporarily wrap 30-40 foot of pull chain around the current head wheel rim pulled tight with a chain binder.
Would not matter if out of balance at the low of speed.
S.U.

3 Likes

The trick then would be finding a solid chain, I think I only have 20 footers, but I would thing that is probably oh 25lbs extra? Ya know one big bummer about direct drive off the engine is yanking that pull chord, I’m pulling over all the rolling mass every last ounce with that starter rope. Whoooooo-eeee! I think it needs some kind of disconnect with a serpentine belt clutch something or other actuator to then engage after the engine starts. That way I maybe wont rip the chord or the whole engine off the thing starting it :joy:

2 Likes

Part way joking, but just hammer in a ton of rim weights and tape weights :joy:
If you’re lucky you might get 10lbs added

3 Likes

I suspect you already know about this Norman, but others might not. Here’s a way to make a low cost clutch.

5 Likes

I worked at Eaton Corp in the torque control division (locking differentials).
Testing of differentials involves a lot of impact loads. A couple impact testers that were intended to test impact loads would involve mounting the axle in a fixture. One axle shaft flange was bolted solid to the fixture. The other axle was also made secure to the fixture but through a sensor that would read the torque load. The testers had a steel flywheel that was spun to a specific rpm and then a clutch engaged to transmit the energy into the differential. If I recall correctly one of the flywheels was 500lbs and the other 750lbs.

The input pinion gear shaft does fail on occasion but more often it is components such as ring and pinion gear teeth, internal differential gears/components or axle shafts.

They would purchase axle shafts from aftermarket suppliers such as Moser - often dozens of them at a time. Testing a differential might require hundreds of impacts that would result in the axle shaft breaking before the differential failed. The broken axle shaft would be replaced and testing resumed. If the ring and pinion gear teeth failed - the they could often be rotated to an area where the teeth were still in good condition and testing resumed.

Unfortunately there is no means of an individual to know where a particular axle would fail under abusive conditions. In the case of a chunker I would consider a full floating axle design to be preferred for strength and safety. If an axle shaft were to break - the rim or now cutter assy - would remain fully retained upon it’s bearings.

11 Likes