Does size matter?

[wrh51]

Now that I have your attention, I have a question about ahem... cylinder size. I am in the R&D phase of building a splitter. I was set on a 5 inch cylinder 24"-30" stroke. I am designing my splitter in a matter that I could theoretically build it into a processor down the road. I have got some great ideas from others on here btw. So I have looked at a lot of processors designs, commercial and home built. It seems that a lot of the processors have 4" cylinders and they seem to handle decent sized wood. I understand the trade off on cycle time with cylinder size. With the pump I have, I don't think the cycle time is going too slow for what I want. I want to have a four way wedge, maybe a six way but only in pretty straight stuff. So my question is... Do I really need the 5"? I don't really plan on cutting nasty stuff like crotches or something real knotty. Oak, probably a lot of cherry, stuff less than 24" or less. I can afford to be a little picky and toss the ugly stuff. What say you?

 

[Guswhit]

Really, too many variables to give you a single answer for this question. Examples, I first built my splitter in '92. I copied a hydraulic splitter that a friends dad had. The things I changed for starters were, made it taller to fit me so I wouldn't have to bend over, made it horizontal and vertical for the larger pieces instead of a lifting platform(I thought the larger rounds would end up twisting my frame as I had seen that happen on some) and finally, I used an axle from an old hay wagon with large floatation tires to help traverse frozen farm fields and take some of the bounce out. Of course as time went on, I thought it was too slow(4" cylinder, 12 hp motor and 16 gpm pump), so I uped the pump to a 22gpm. Then I started getting larger wood and thought, hmmm, I need a bigger cylinder(8" from a D-8 cat), but then it was too slow again so a 28 gpm pump got installed, but of course motor was too small to run hydraulics, so then came a 20 hp Honda. So lessons learned, bigger is not always better, do more home work than I did so your build fits your needs. My do over would have been a supersplit, but we just didn't have information available at our finger tips the way we do today. If I could sell mine for just what a supersplit cost today(not what I have invested in it over the years), I would trade in a minute. I am getting too old to handle the 36-48" pieces that I never backed away from before. I'm also lucky enough to have several farmers that like me to go along there fence rows and thin them out, not cut them down, just thin them, so I get lots of cherry, and black locust in the 12-20 inch diameter and I just don't need a splitter the size I built for that. I think you need to make a list of the features you really want, i.e., speed, elec start, size of wood you handle, production. Then start making a list of parts you need, calculate your costs of purchases and time involved and see if you think it is going to be worth while. Don't get crazy like I did without the research! Don't let people goad you into it either, like what happened to me! Good luck in your journey!

 

[Festus]

My 4 inch works fine with a single wedge, but if I were using a 4 or 6 way wedge I seriously doubt it would be all that great. If you are using a larger pump, you might as well go with a larger cylinder. IMHO

 

[muddstopper]

A 4in cyl with a 4way works pretty dang good. My splitter is home made and I was using a 14gpm single stage pump,25hp Kholer engine and 24in tall x 16in wide 4way wedge. I never stalled it on anything and I am always splitting 24in dia and up size hardwoods. I did just get thru upsizing my cyl to a 5in with a 28gpm 2stage pump, but I also added another set of wings to my wedge to make a 6way. I do think a 4in cyl is a little small for a 6way wedge, but would probably work on most everything but the really knotty stuff, which I get a lot of.

I would also think hard about the type of beam you mount whatever cylinder you get. 4way and 6way wedges can twist the heck out of a hbeam. If you think someday you might built this splitter into a processor, you dont want to have to sort thru your logs trying to find something that will pass thru the splitter without breaking something. Over build it and you wont have to repair it later.

 

[Tazfreak]

Now that I have your attention, I have a question about ahem... cylinder size. I am in the R&D phase of building a splitter. I was set on a 5 inch cylinder 24"-30" stroke. I am designing my splitter in a matter that I could theoretically build it into a processor down the road. I have got some great ideas from others on here btw. So I have looked at a lot of processors designs, commercial and home built. It seems that a lot of the processors have 4" cylinders and they seem to handle decent sized wood. I understand the trade off on cycle time with cylinder size. With the pump I have, I don't think the cycle time is going too slow for what I want. I want to have a four way wedge, maybe a six way but only in pretty straight stuff. So my question is... Do I really need the 5"? I don't really plan on cutting nasty stuff like crotches or something real knotty. Oak, probably a lot of cherry, stuff less than 24" or less. I can afford to be a little picky and toss the ugly stuff. What say you?

Hi,had hydro splitters since early eighties,I split only hardwood,we have no softwoods here.All my machines purpose built for tough ,interlocked hardwood,U said u don,t really plan to split tough wood but if ur supply changes from free splitting timber to tougher timber?I contract split so I need a machine capable of anything I put through it.Cylinder size and fast hydraulics to split what u mostly work with plus go a bit bigger in both should meet ur needs.Machines that do their intended job easily without undue stress r the go.JMO.

 

[Oliver1655]

I have a 4" cylinder & a 4 way option, pressure relief stet at 2500 psi. It does ok for splitting most wood with the 4 way. (Has to drop into 2nd stage/low speed on the pump a lot). When using single wedge it will split in the first/high speed stage 90% of the time. On the occasions where I have really ugly knots/twists, I just remove the 4 way & split with a single 8" high wedge.

I am in the process of gathering components for building a larger splitter to use with multi split wedges. 6" cylinder, 50 gpm single stage pump, 8" 40lb wide flanged beam with a 1"flat of cold rolled steel welded to the top of the beam, ...

In your situation my recommendations:
- 4.5" cylinder
- 22 or 28 gpm 2 stage hydraulic pump
- Minimum of 1/2" thickness for top flange of beam. On the above mentioned splitter I used a 6" wide flanged beam which has a top flange thickness of just over 1/4". I bend it frequently, just keep a 12lb sledge hammer handy & tap it back in shape then keep splitting. (I did not have this problem while just using the single wedge). This is why I will be building a heavier duty splitter.

This will give you enough tonnage for the 4 way & still have a good cycle time.

This is lessons learned when I built my splitter wedges:
- 1st wedge single edge, only 6" tall, too short. (Now if I had the 4 way at that time it would have been good.) Added 2" flat making it 8" high, better but I would go 12" tall if starting over. It will help cut the strings on the larger rounds.
- It also had 2nd stage wings/wider wedge to "POP" the wood open. I clipped the wings & it works better without them.
- Because of the above mentioned strings, I made my 4 way. (Up side down "T") The horizontal 1/2" x 6" flat splitting edge is set back about 2" which allows the wood to split vertically then horizontally reducing pressure needed to split & reduces stress on wedge as a result.
- The 4 way adapter slides down over a 2" solid square bar which is welded in the 2-1/2" sq tubing at the back of the wedge. Since this was an after though/experiment, it is not height adjustable. (I didn't know if the 4" cylinder / 2500 psi combo would be enough for a 4 way but found it was for straight grained wood and if I was careful, most others.)

Tried to upload some photos of my wedge system which I built before I found this forum & had other examples to learn from, but alas, even though I have many times in the past, this morning, they wouldn't upload.

Summary:
- 1/2 or 3/4" thick flat steel 6" wide x 12" exposed height works well for a single wedge. You do not need to have a "V" shaped wedge just a "V" ground edge to the flat. In fact with a good edge, you are able to cut through the hard to split pieces.
- Offset the secondary splitting edged for the above reasons. If you do not want the horizontal splitting edges to be adjustable height, determine the largest diameter split piece you could use & set it to that height.
- Most importantly, use the beefiest wide flanged beam you can to help prevent it from bending.

Happy building! :msp_biggrin:

 

[blades]

Alternative to the common I or H beam , 1/4" walled rectangular tubing. I used 4x6 welded together to yield a 8"x6" fully boxed beam, eliminates almost all torque stress and almost no vertical deflection from my 5" cylinder apx 30t. Then added a 3/8" x8" top plate. Full length of beam. Note wedge needs to be attached to actual beam not the top plate. ( if an adjustable wedge wanted, the tubes could be spread apart. You then need to welded an equal sized filler top and bottom to the 2 tubes to maintains structural strength Used angle iron for guide rails ( welded to tubes not top plate) although there are other ways of doing that as well. Another note is the push plate should be 2x longer than high and as tall as the wedge or taller, in big rounds there is a lot of force on the top of the push plate so that area needs to be reinforced by supporting that area to the rear of the base plate. I used a thin wedge ( 1" thick ) 8" deep, 12" tall that is backed up by a 1/4" walled 2" square tube to act as a spreader ( could be larger, what I had on hand). Works well. Thin wedge slices through stringy and most knots v/s a Wide wedge reduces the load on the wedge by more than 60%. Which also reduces the stress on the beam. About the only time my little 11 gpm pump kicks down is in nasty twisted knarly stuff.

 

[wrh51]

Thanks all for the advice. I think I will go with the 5". I would like to a find a cylinder with a 3" rod. I haven't seen much through the normal routes, Bailey, Surplus Center, Northern etc. Anyone know where to find one?
I planned on overkilling the beam. The beam on my shop press that I built is 18" tall with 3/4" flanges and web. I will build the splitter with a beam similar to this and add some gussets along the length.
I have another question. I plan on running the splitter off tractor PTO. The pump I have requires about 40 hp at 1200 rpm for appropriate flow. I will need to go back and look I think I can run it up to 1800 rpm. I will need to somehow increase the PTO speed through belts and pulleys or gearing. I have looked (on the internet) at commercial processors that are tractor powered. I can't find anything showing the detail of how they are accomplishing this. Is it as simple as a multiple belt drive? I did look at the PTO pumps but they do not have the flow and pressure that I need/want.

 

[muddstopper]

Thanks all for the advice. I think I will go with the 5". I would like to a find a cylinder with a 3" rod. I haven't seen much through the normal routes, Bailey, Surplus Center, Northern etc. Anyone know where to find one?
I planned on overkilling the beam. The beam on my shop press that I built is 18" tall with 3/4" flanges and web. I will build the splitter with a beam similar to this and add some gussets along the length.
I have another question. I plan on running the splitter off tractor PTO. The pump I have requires about 40 hp at 1200 rpm for appropriate flow. I will need to go back and look I think I can run it up to 1800 rpm. I will need to somehow increase the PTO speed through belts and pulleys or gearing. I have looked (on the internet) at commercial processors that are tractor powered. I can't find anything showing the detail of how they are accomplishing this. Is it as simple as a multiple belt drive? I did look at the PTO pumps but they do not have the flow and pressure that I need/want.

Surplus center has a 5inbore x 3in rod cylinder, but it will cost a lot more than the $200 cylinder you can buy at NorthernTool. Another option would to be use two 4in bore x 2in rod cylinder. This would give you the same tonnage as a 6in bore cyl with a similar strength as a 3in shaft. This would also allow you to mount the cyl side by side or stacked to provide more support for the pusherblock. This is what I had in mind for the processor I am planning to build.

Since your plans do include a processor in the future, I cant say enough about beam strength. The siamese 4x6 box tubing as suggested is a good starting point and more than enough for most operations. This would give you a web of 1in thick and the box design yields extra twist support, but to be honest, I can bend the heck out of that design. I currently have 2in web thickness and one inch flange thickness, with a addition a 1/4x6in channel to box the beam, and I twist it with a 5 in cylinder. Mind you I split cull large dia wood from timber operations that are mostly crooked, forked, twisted, junk for anything but firewood. Stuff most processor folks would avoid like the plague before even considering running thru their machines. My plans for a beam are to use a 8in w hbeam with re-enforced web and flanges. to also weld supports from the outside of the bottom flange to the inside of the top flange to form a triangle which will be stronger than a box design. To each their own when it comes to beam design and most folks dont need to build to the conditions I work in. Built it strong at the start and you wont have to fix it later.

I will also second the tall wedge suggestion. I didnt stop at 12in tall wedge, I went with a full 24in tall wedge. I hate strings holding large splits from falling off the wedge. Wedge designs will also come with many suggestions and they all work. I prefer a thin wedge with a very long sharpend edge. I keep mine razor sharp. If it wont split it will slice and dice. I like to go back 2 1/2 inches from the edge and sharpen to a fine point. For mulitple splitting wedges, it pays to just sharpen one side of the wedge. For a 4way wedge, you can sharpend both sides of the edge with little negative effect. For 6-8-or more way wedges, it pays to just sharpen the outside faceing edge of the blade to prevent binding as the wood passes thru the wedges. Angleing the wings so they are wider at the back that at the cutting edge is also a must. .