Wood splitter design

Tacotodd · September 16, 2021, 04:49:39 PM

It's like Mike said, so be sure that it's in a shear plain & not a bending area. Much less likely to bend that way. Similar thought process to my receiver shackles that I use. They go in my hitch frame and I've NEVER even gotten a whimper from the pins. So overloaded that with a 4part line on my hot rodded & severely UNDER rated winch (it'll break 5/15 aircraft cable on a straight pull & it's only a 8k winch but the cable is rated @9800lb min breaking strength) and they've NEVER gave me any problems, AT ALL. And that stalled the motor!

Crusarius · September 16, 2021, 05:04:09 PM

mike, that is why I came up with option 2. I very much would expect that pin to bend.

JoshNZ · September 16, 2021, 06:43:00 PM

The pin down at the wedge end isn't under any pressure during splitting. The back of the wedge is flat, and the gullet (?) of the clevis end is flat and square (fillets machined square too). The hole is placed so that the pin is only lifting the wedge back up.

The pin at the top end is a 1-1/4" pin and bugger all room between plates and eyelit. A little, in case I ever go with a bigger ram. This rams bore is only 85mm internal so it's not going to be crazy. But it's going to be fast! If I set the relief valve to 3000psi then it's just shy of 12 ton.

Ive had my ram down at the hydraulic shop for a week waiting on seals, I figured I may as well while I've got it apart but nothing got done there due to parts of the country in lockdown so I went and picked it up and will circle back to that.

Parted the excess end off the rod, parted the base off the cylinder. Turned a new end cap, and welded it on, it was all pretty clean so did it in 3 passes with the tig.

The friend who did all the plasma cutting keeps any decent dropouts in 20-50mm plate for me for this sort of stuff. I rough cut it with the torch then machine into shape. All tedious stuff and hard on the mill

Stretched it all out, welded on the bracket then cut the excess beam off with the torch then tidied up and welded on the cap/stiffiner.

And the splitting mechanism is pretty much finished. Just a few stiffiners to add up each side of the beam, and feet to the legs. Ill have to pull the ram apart and add ports later, hopefully I've got seals to go in by then.

So I can start the ramp now. If I'm still going to do it haha. I don't think I need an outfeed, it all goes into kiwifruit bins which is just as easily parked next to the table.

Not too fussed about the stowing either, some good ideas here that will be able to be utilised later, if it is too heavy to just lift.

I still haven't really got a solution I'm happy with yet, in terms of the chain conveyor. One that will handle the widest of rounds I'll ever see, right down to 8" rounds. The only way I can think of it handling the smaller is if they get laid across it, and they'll want to roll. If they went on length ways the chains would have to be 6" apart max, and then that's pretty narrow for wide rounds. I'd have to be adding pretty tall spikes to stop them rolling. I could add lengths of bar/angle between the chains, lower than the spikes and then put a slide base of some sort under it so the bars slid the small stuff up the slide.

I don't know. None of it is very elegant. Appreciate all the input and thoughts!

Hilltop366 · September 16, 2021, 07:27:40 PM

If you were to put cross bars spaced apart a bit more than your longest block the smaller stuff could get laid down in between the bars (more than one piece would fit) the larger pieces could fit in between the cross pieces but sitting on the flat.

JoshNZ · September 16, 2021, 07:49:34 PM

Yeah I'm thinking along those lines too. Would mean I'd need a slide for the small stuff to slide along when pushed by the bars though. All extra material.

Here's a curve ball ???

I plumbed up one of the oil motors to a spare spool on my press today, perfect RPM but don't know what the heck I'll do with a wobbling shaft. I assume it interfaces with a bearing supported shaft with a female splined that allows the wobble. And would need to be bathed in oil I guess... Frustrating

hydraulic motor - YouTube

JoshNZ · September 16, 2021, 08:18:16 PM

Actually I've got a box sitting there of 50lbs of stainless flat bar pieces. 1/4 thick by maybe 4"x30". Could make up a slide out of that.

Sheesh that oil motor is a ballsup huh.

I'm thinking there is still a centre of axis from that output. Is it worth me pulling it apart and working out offset.. I could turn a shaft with the same offset in the 4 jaw chuck then weld to it. Doesn't take care of the oil bath situation though. Would need to make a housing, and make a shaft seal. DanGit

Crusarius · September 16, 2021, 08:28:32 PM

are you going to support the rod end of the ram so it doesn't want to bend?

JoshNZ · September 16, 2021, 08:34:52 PM

I hadn't planned on it actually, do I need to? It wouldn't be too hard to weld a bracket to the rod end of the ram and bolt it to the beam

Al_Smith · September 16, 2021, 09:16:20 PM

It looks like you are handy around machining practices so it wouldn't be hard to make a "saddle" clamp on the end of the cylinder .

JoshNZ · September 16, 2021, 09:24:20 PM

Yeah I could secure it easy enough. The thought hadn't even crossed my mind. I assumed any ram was built strong enough to be supported at each of its ends without bending.

Hilltop366 · September 16, 2021, 09:30:26 PM

The rod looks quite sturdy if it is of good quality you would not think it would be an issue being 12 ton.

In order to fasten the gland end too it will have to be perfectly alined with the beam, if there is any difference in height from one end to the other (centre of pin to pin) or bend in the web of the beam it will change the gland end height as it extends and will cause it to bind if both ends of the cylinder are fastened.

One advantage of a sloppy fit I guess.

JoshNZ · September 16, 2021, 09:40:55 PM

I'll give it a go without fixing first. Will get a run before going to sandblaster.

The oil motor is a no go, the case drain port is from outside what I've got here so it's made to have a housing, I'd be looking at fabricating one with a shaft bearing and seal and I sure can't be stuffed with that.

I've got a spare gear pump there I guess there's no reason that can't run as a motor.

mike_belben · September 16, 2021, 10:24:12 PM

If those are bobcat wheel motors theyre a mint. Mine are wobbleshaft with case drain.

The rod will be fine

JoshNZ · September 16, 2021, 11:09:20 PM

I'm sure they're great when they're mounted to their output device. Unfortunately what you're looking at there is all I've got. Not much use to me as it is.

mike_belben · September 17, 2021, 06:48:17 AM

The wooble end could be turned and keyed or have a lovejoy rollpinned on.

The case drain port can be tapped for NPT drain or plugged and tapped elsewhere for better location. Make it work.

moodnacreek · September 17, 2021, 07:58:35 AM

That cylinder looks rather small bore wise. It will be fast.

VB-Milling · September 17, 2021, 08:05:15 AM

Quote from: JoshNZ on September 16, 2021, 08:18:16 PM
Actually I've got a box sitting there of 50lbs of stainless flat bar pieces. 1/4 thick by maybe 4"x30". Could make up a slide out of that.

JoshNZ · September 17, 2021, 04:15:44 PM

Quote from: mike_belben on September 17, 2021, 06:48:17 AM
The wooble end could be turned and keyed or have a lovejoy rollpinned on.

The case drain port can be tapped for NPT drain or plugged and tapped elsewhere for better location. Make it work.

The trouble is oil leaks past that drive link (intentionally so) so that both ends of the drive link are lubricated (the drive link being that wobbling shaft). The case drain picks up from the outboard side of the motor. So I could couple to the end of that drive link with a universal joint but I would then have to build a case around that coupling. Then I'd have to seal between the case I'd made and the shaft, which means I'd need to support it with bearings too.

I could just couple to that shaft and grease manually but it would forever drip oil.

I'd love to make something work because it is the perfect RPM and more torque than I'll ever need but I think it's a deep deep rabbit hole lol.

mike_belben · September 17, 2021, 07:08:24 PM

ahh.. thats pretty interesting. id guess they are skid steer based but then that means the chain case box is filling with hydraulic oil over time? i dunno.

moodnacreek · September 17, 2021, 08:26:26 PM

Wrong motor for sure. If it's speed is right you would need to figure the motor displacement to order one that is sealed.

JoshNZ · September 18, 2021, 05:46:02 AM

I am close..!

You guys are gonna love this, if it works. I need another few hours on it yet.

Orbital motor - YouTube

kantuckid · September 18, 2021, 09:11:24 AM

I own a TSC, made in USA 3 pt hitch wood splitter which is no longer sold by them. it's made in Colorado and very well built. I sent the OP links to where I have it advertised with pics to see the design. The cylinder is 4" x 24" and has a two sided clevis on the held end. I've never seen anything it wont split. It pivots from horizontal easily thus allowing big log sections to be rolled into place w/o lifting them. I took it into the woods and split onto a trailer with the splitter staying on my tractor as I split. It might not be fast enough for larger volume firewood sellers but easily would handle a smaller operation or bulk users needs. makes sense to avoid yet another small engine to maintain when many own tractors who burn wood. The prices on buying one have more than doubled in recent years.
This splitter requires either front or rear remotes, not PTO! Given that it's free standing or hitch fastened- it works on the ground, front or back.

Al_Smith · September 18, 2021, 01:08:12 PM

I've seen several home builds that use PTO driven pumps and they did pretty well .I think they used higher volume single stage pumps from like a dump truck .A tractor obviously on the PTO would have more usable power than a small engine but at some where around 540 RPM it would need the higher volume pump else it would be slow as a snail .

mike_belben · September 18, 2021, 02:22:17 PM

Yes a 540 pto pump needs to be about triple the displacement of a gasser to work well.

Josh you made a faceplate to block the drainage and turned the wobble shaft splines off to a straight shaft right?

JoshNZ · September 18, 2021, 02:53:25 PM

Not quite that simple as even turning the splines of that shaft off it would still orbit at one end and not rotate on an axis. Would make sealing against it impossible.

I basically used a faceplate off one of the other motors and flipped it around, and machined journals to hold tapered roller bearings. Then took the geroler bit with splines from the same donor motor and turned it to fit on a shaft which I welded it to. That's what you're seeing on the output there.

I'll post a bunch of pics if it works. I still need to add a sleeve to the outside to hold the outboard roller bearing and shaft seal, but after that it should be the real deal, fully lubricated and sealed like the original unit. Only with a reduced torque due to the weld in the shaft. I'll tap into the case drain galleries further down in the case and block them at the face where it mates.

I can't remember what Ive said about the PTO but, it seems absurd that pumps and gearboxes are all rated for 540rpm, who splits wood with their tractor sitting there near wide open throttle?

I figure 1200rpm is heaps which is only about 300rpm on the PTO. I found a slasher gearbox pretty cheap and it's a 2.8:1 ratio so that gets me to 840 rpm. From there I've either got an 85cc pump I'm looking at which would be ~71L/min or 19gpm. Or I could pick up one of those hydraulic pump gearboxes that steps up by about 3.5 and runs a normal group two or group three pump, I'd get close to 3000 rpm that way. Not sure how the math works out for the first gearbox if I do that. I guess if it's rated to 50hp and it's a 45hp tractor doing 1200rpm, I can't wreck it can I