Log Splitter Design Questions

[NELOG]

Hello,
I'm thinking about builing a high production, extreme duty log splitter and have a few questions for all of you.

First of all, what type of steel do you use for the I-Beam? Will any one work, or are some types better than others? What dimension beam would you use?

Has anyone made a splitter with a fixed wedge that has more than one upright blade (sort of like the Mulitek 16-way wedge -see http://www.multitekinc.com/stories/PDFs-images/gish.pdf ) If so, do you have any suggestions as to making them work well?

Has anyone used more than one cylinder to push the wood through the wedge? I saw a splitter on eBay a while back that had two cylinders, one over the other. For larger diameter wood, this seems like it would provide the necessary surface area (and so, pressure) required to split the wood as well as a better position from which to apply this force (for example, when pushing a 30 inch-diameter log on my Iron and Oak splitter (9 inch compound angle wedge with 5 inch cylinder), the piston flexes down, presumably because the force is being applied to the lower part of the log and not evenly, because the piston only pushes about five inches above the plane of the beam.) As far as hooking more than one piston to a single control lever, it seems that the flow from the working ports could just be divided, however I suppose the load on each cylinder might be different, depending on the shape of the wedge and the log. By the same token, if the cylinders are hooked together, shouldn't their pressure equlize and their extension/retraction as well? Any suggestions would be appreciated.

Finally, has anyone ever used two I-beams, one on top of the other or next to one another, to reduce flexing? What sort of cross-bracing do you use to counteract this phenomenon with a single beam?

Thanks for any and all suggestions. Pictures would help explain and clarify.

 

[Rayco Man]

Log Splitter

If you want to build your own heavy wall box tbe will work and weld a flat steel top plate to guide the wedge.

 

[tawilson]

I didn't make mine, but the person who did used two 4" i-beams. There is no flexing, but they used a flat plate welded to the top to slide the plate on instead of using the top of the i-beam, and as I made improvements to the splitter, that became a weak spot. I added to the height of the wedge, and the extra leverage caused the plate to pull loose. I got it back down and rewelded and added some support to the wedge. Been ok for a while now. Using two cylinders sounds good, but on smaller wood the bottom cylinder will get the load and the top will want to extend more and might cause a problem. I don't know if there's a divider that would ensure equal volume to each cylinder, if so that would take care of that. This is an old pic. Since then I've replaced the reservoir and added an auto-return valve.

 

[CaseyForrest]

I am in the process of building one. I am going to use 5" square tube since its free, and weld a 3/4x6" flat on the top for the wedge to slide on. I also have at my disposal plenty of I-beam, but feel the tubeing will hold up better. I thought about using 2 cylinders, I have either one 5.5" or two 3.5" cylinders. Pressure between the two cylinders will equalize on their own, but you should split the hydraulic lines and then go to each cylinder, not run your line to one, and then the other. As far as when you are cutting a small piece, and have only one cylinder actually doing the splitting, if you build your wedge heavy enough, the difference in presure on one or the other wont matter. I also have enough 1" flat to build the wedge and make end pieces. So far the only money I have spent for it is the 8 horse honda motor, I still need to buy the pump, mounting bracket, and valve. SHould be one bad ass splitter that isnt costing me much at all.

 

[NELOG]

More ideas

Thanks for all of the insight. What type of I-beam do you use for a splitter. Will any work, or is there a certain type of steel that best suits the application? Also, will any mild steel work for the wedge? What advantages does tubing have over an I-beam?

 

[Stump Man]

I used what they call h-beam which is thicker than I-beam. Had a 4' srtroke with a fix wedge. Bought most of partts from Northern Tool. Had an auto valve which you pushed forward and piston would go out and split wood and return auto. You had to carefull with it and wonder if OSHA would approve of it. At that time we used a Wisc VG4D 37 hp engine and an 35GPM Pump. You can use a smaller engine with 2 speed pump. We drove the pump off front of engine and rockford clutch on rear to operate a table cut-off saw. We could split a cord of 4' long wood in about 20 mins with 2 men and then cut the 4' split wood in about 30 mins with two people. Hope this helps you out.

 

[WESCOMAN]

What will be the hardest splitting wood you will split? What is the average diameter? What will be the hottest working environment? What Tonnage splitter have you used so far that has worked good? How many hours a day will you be splitting? How many days a week? Give me those answers and I will see what I can design for your needs.

 

[B-Edwards]

A t is all i think you'd need for 2 rams.

 

[B-Edwards]

oh i'd weld the plate so both would be the same as far as 1 out running the other. simple solutions i know, but im pretty simple 8)

 

[CaseyForrest]

Allright, I think mine is going together this weekend. After much debate on a 4" cylinder and a 5" cylinder, I think Im gonna save some money and get the 4". I know you all are saying..."WTF", but I figure if I build a wedge to fit on the end of the splitter, I can increase the PSI being put onto the log. So in effect I will have 2 wedges, one on the ram, and a slip on one for the end. Anyway, was doing a little remedial math and was wondering how a company can sell a 22 ton splitter with a 4" cylinder. Heres some simple math....a 4" cylinder has an effective area of 12.57 inches, if you are running at your MAX of 3000 psi, which most dont, then you have a tonnage of 18.885. Not even close to the 22 they claim, and most valves are set at 2250 from the manufaturer and are not adjustable, which would give you an actual 14.14 tons of force. Hmmmm...I may be missing something, but have figured it many ways to Sunday.

 

[woodchop]

One thing to consider is that If you have a knot in the log that you split with the two wedges, something has to give because of the twist in the wood. The weakest part will probably be the pusher and could damage the cylinder.

 

[CaseyForrest]

Well, after another day of thinking, I may mount the wedge on the beam, and use the cylinder as a pusher. In any case, whatever is attached to the cylinder will run on a track on the beam. I may even tie the front of the cylinder to the beam to offset and lateral forces as well. I just got my cylinder and pump, 4x24x1.5 and 16 gpm pump. Valve and pump mounting bracket should be here this Friday. I have a Honda GX240, 8 horse just waiting to be put to work. I am using 5" square tube, 1/2" thick as my main beam, and welding a 6"x3/4" piece of flat to the top for the wedge to slide on. On the end the cylinder will mount to the beam I may cutt off 12" of the beam and weld that vertically as the end of the beam. I also got the thinking, I will never tow something so small behind my truck, I will always load it on my trailer, so why not make it 4 wheeled, like a wagon with a garden tractor front axle the will steer, and then I can put a handle on it and pull it anywhere...what do you think?

 

[NELOG]

Thanks for all of the tips. I personally think that splitters that have the wedge mounted on the beam are better than those that have the wedge mounted on the ram.
If I had two upright wedges, but two cylinders as well, it seems unlikely that a knotty piece of wood would bend either or both of them, especially if they had fairly large rod diameters.
As far as the cart idea, its a very interesting one. I never tow my Iron and Oak more than two blocks, though it is supposed to handle 45MPH. Adding two axles, though, means that it may not set up welll on uneven ground. (i.e. a chair with four legs might rock on an even floor, but a three-legged stool always has all three feet on the ground.) If you just left the regular axle and then added a jackstand to the end opposite the axle with a large 8" or 10" pneumatic caster from Northern, it seems that it would be very portable, stable, and easy to steer.
As far as the I-beam or H-beam that you use on a splitter, are there different types as far as type of steel. I know that when they demolish buildings they have large red beams. Are these just painted? How can you tell what type of steel a beam is, or are all compositions appropriate for a splitter?
Also, has anyone tried to make a wedge similar to the TW-7 box wedge? I know that they use a custom fabricated tube for the frame, but it seems that it would be farily easy just to put on a heavily reinforce H-beam, and, because the wedges aren't too tall, the force on the beam (and thus the tendency to flex) is greatly reduced.
Finally, for the pushblock, do you have any tips on making a durable one? The one on my iron and oak is pretty good, with teeth on it to prevent the logs from popping off the beam (aided by an angled wedge) but I've noticed that, because of the wedge, which slopes out after the first four or five inches, that the logs skid along these teeth. What do you think about these? It seems that timberwolf doesn't use them on their splitters. Additionally, how far back should the plate go on the beam? It would make sense that a longer plate would prevent flexing of the piston under load.
Any other suggestions and pictures would be greatly appreciated.

 

[CaseyForrest]

you are correct about 3 legs as opposed to 4, but if the front steer axle pivots in the center, that would take care of any uneven ground. Only reaso I am thinking about a cart style is I work by myself, and alot easier to pull something than have to hold it up and pull it, and I would be able to get it into tight areas by myself, without having to back it in with my truck.

As far as the steel you see from buildings, the red is just a primer coat to keep the steel from rusting. I dont believe that there any composistion differences that would make you need to worry about strength. Just make sure whatever you use is heavy enough. Or stiffen it up. I believe that the 5" square tube, 1/2 thick with a 3/4 by 6" flat welded to the top will be overkill, but also will not flex or break, I hope!

 

[NELOG]

Thanks for all of the ideas.
Does anyone have an opinion about the splitter's pushblock? On my current splitter, the holes are square, which has sheared several bolts. Also, it seems that a longer pushblock would prevent excessive side to side stress on the splitter ram. What do you make your pushblocks out of? How are they designed? Thanks a lot.

 

[NELOG]

any thoughts or pictures on pushblocks? Thanks

 

[CaseyForrest]

Try a piece of 5" or 6" C channel stood on end about 8" long. Then wherever you are going to mount your cylinder to it, box it in, thats what I am going to try to do.

 

[woodchop]

any thoughts or pictures on pushblocks? Thanks

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