New splitter ideas

I have decided to make my own splitter 15 - 20 hp eninge 22 gpm pump
5 inch bore cylinder 20-24 inch stoke (cylinder depends on what is avaiable) movable wedge 4way, log lift undecided on cherry picker or table style log lift. i have read alot of information on here in regards to wedge design/angle going to be a 1 inch wedge with 2x3 angle along the length to pop it apart 4way wedge will slide up and dwon simalar to timberwolf style.

Now here is the question what size beam is best suited to this? I already have a 4x8 beam with 1/4 inch. Is this going to handle the abuse without any further need for stiffiing? Or would I need to add something like a peice of 1x8 plate on top of beam to make a machine like way for pusher to slide on and to stiffen the beam? Hope this makes some sense

Thanks for your input
Adam

gulity1 said:

I have decided to make my own splitter 15 - 20 hp eninge 22 gpm pump
5 inch bore cylinder 20-24 inch stoke (cylinder depends on what is avaiable) movable wedge 4way, log lift undecided on cherry picker or table style log lift. i have read alot of information on here in regards to wedge design/angle going to be a 1 inch wedge with 2x3 angle along the length to pop it apart 4way wedge will slide up and dwon simalar to timberwolf style.

Now here is the question what size beam is best suited to this? I already have a 4x8 beam with 1/4 inch. Is this going to handle the abuse without any further need for stiffiing? Or would I need to add something like a peice of 1x8 plate on top of beam to make a machine like way for pusher to slide on and to stiffen the beam? Hope this makes some sense

Thanks for your input
Adam

Click to expand...

So, your beam is 4" wide 8" tall and only 1/4" in thickness? That is pretty thin, when you put down the kind of power that you are talking the beam won't be able to handle it when you hit that second stage on your pump when it kicks down fighting with a big log. The splitter that my dad and I are going to build this winter has a beam thickness of a little over 3/4, to most this might be over-kill, but if you want it to last a long time, with repeated twisting from all the big logs, you are going to want to make it bigger. I'll try and find a few pics to post to give you some ideas, I like to share!

Max

hooked up to the old Rancher...

4 x 8 x .255 flange thickness = W8 x 13 beam (8" tall by 13lbs per foot) This is going to be awful light for a 5" cylinder. Here are the basics of finding a beam.

I take the force in pounds you want to deliver times the height of your splitting wedge. So for your 5" cylinder x 3000 psi gives you approx 30 tons so 60000 lbs. Say you build a 12" tall wedge.

60000 x 12" = 720000 in lbs <-- This is the max moment (torque) you will place on the beam.

Divide this number by 21600, this is the max tensile stress we want to put on the beam. It is basically a 1.5 safety factor on an A36 beam.

720000 / 21600 = 33.3 in^3 This is the section modulus that you have to have greater than to assure your beam is strong enough to resist the moment (torque) you could put on it.

Now you need to find a chart that lists the section modulus for W-beams. Here is one:

http://www.engineeringtoolbox.com/american-wide-flange-steel-beams-d_1319.html

The section modulus is labeled "W" in this chart. ASIC labels it "S" if you look it up in the back sections of a machinery's handbook for example.

Look though the chart (I printed the pages out) and go hunting for your beam. The chart I linked to does not have the flange thickness listed. You can get the dimensional info from a steel supplier stocklist http://www.ryerson.com/stocklist/StocklistServlet?COM=GetTable&ID=916

For example my splitter has a 5" cylinder 3000 psi system pressure and a 12" tall wedge. My beam is a W8 x 48 -- 8.5 H x 8.110 w x .685 flange thick. The section modulus in the x-x direction is 43.3 so I am good.

A word of caution: be careful of tall skinny beams! The will show strong enough but they will twist!! When designing steel structure there are additional calculations done to be sure that the beam does not twist under load and whether supports are needed to prevent this. Most log splitters use 1 beam (ie no buddies to support from) so keep your beam shape pretty square. I wouldn't get any narrower top flange than 6".

This is a conservative approach. Some could argue to use half the height of the wedge or the pin height of the cylinder mount instead of the entire height of the wedge. This will give you a smaller needed number to beat but your splitter my have more spring to it when pushing it to its limits.

You should be able to plate the top, bottom and both ends of the beam you have and get something that will work. Otherwise print out a chart grab a tape and start hunting.

Don

SWI thanks for the information I have gone to a different scrap yard looking for some flat bar and found a whole lot of beams so that will work out I am sure I will find what I want there. I am going to build a 12 inch wedge maybe a bit taller 14 Unsure yet I will see how materials shape up. I will countiue to update and ask stupid questions and pics when needed. I am going to try to pic up new beam and some flat bar tomorrow I also will hopefully be cutting in a new stand of oaks we will see how the weekend looks. Thanks for all the input

Sorry to dredge up an ancient thread but I'm doing calculations for my first splitter build and the stress calculation method is very helpful, particularly the section modulus. My question is whether or not the modulus calculation is equally applied to W beam and rectangle tube. The fab guy in a nearby town says that W-beam will twist easier than rectangle tube so I can use a lighter tube than I would a W-beam. This is what I came up with for possible beams with better than a 33.5 section modulus:

10X12X1/4" tube = 39.32 modulus 36.03 lbs/ft
8X10X3/8" tube = 37.69 modulus 42.79 lbs/ft
8X10X1/2" tube = 48.28 modulus 55.66 lbs/ft
6X8X5/8" tube = 33.56 modulus 51.80 lbs/ft
W8X40lbs beam = 35.5 modulus 40.00 lbs/ft

Since steel is sold by the pound, the 10X12X1/4" tube would be cheapest but if rectangle tube is inherently more resistant to the type of stress induced by a splitter then maybe the modulus calculation would be invalid and I could use a smaller tube successfully. Any ideas?

Bump

What did I hit in the road??..Bumpy Bump

I would vote for using a w beam and boxing the ends if you are worried.. There was a diagram that showed how the beam was stressed and it was really stressed at the ends so having a fairly thick w beam along with strategically bracing would be ideal..

However i have seen box tubing would work if you can get it thick enough to stand up to the stress...

I ended going with a w8 35 beam which is 1/2 thick..even thicker in the web.... for those that dont know this already the 8 means 8 inches wide and the 35 means the beam weighs 35 pounds per foot which is how w beams are rated...

I found the thread discussing the beam flex i was talking about..here ya go

Log splitter beam info - WeldingWeb™ - Welding forum for pros and enthusiasts

Biker Dude said:

Since steel is sold by the pound, the 10X12X1/4" tube would be cheapest but if rectangle tube is inherently more resistant to the type of stress induced by a splitter then maybe the modulus calculation would be invalid and I could use a smaller tube successfully. Any ideas?

Click to expand...

This is exactly where I am at with my splitter design... I can't decide if I want to use a W-beam or if I want to use a recatangle that could also act as the reservoir for hydraulic fluid. I was looking at 8x8" rectangle as a way to get almost 20 gallons of fluid which would be nearly impossible in any other configuration. An 8x8 axle beam that was 3' wide would only yield me 9+ gallons.

Look at member Blades post of his splitter. He uses 2 4x6 tubes welded side by side with 3/8 plate on top. I'm with you guys where did all the structural engineers go :msp_confused: I priced a 20ft 6x6 or 7x7 tube that would be cut in half for my beam and it was like $300 or more, pricey. Still gather parts for my build.
Brian

The main problem with tube is if the wall is light enough it can buckle locally. Once it buckles it loses a lot of strength and can fail quickly. Also you will need to be careful how you attach the wedge & or the cylinder mount as the localized stresses may cause the tube to crack next to the the weld. Generally you are trying to peal the mount or wedge from the top of the beam. If the structure of the beam is not strong enough it will fail and separate from the rest of the beam.

It is easier to weld gussets on a W-beam as it is open and exposed. The web is in the middle and supports the backside of the flanges from localized deflection and failure (pealing). Yes it is a good idea to weld gussets on each end to support the flanges. It does help with beam twist.

There are splitters that successfully built from tube, I would use a thick plate on the top if using a light wall tube.


The FEA picture is deflection not stress. The right side is shown fixed and the left end has a force placed on it.

Don

kyle1! said:

Look at member Blades post of his splitter. He uses 2 4x6 tubes welded side by side with 3/8 plate on top. I'm with you guys where did all the structural engineers go :msp_confused: I priced a 20ft 6x6 or 7x7 tube that would be cut in half for my beam and it was like $300 or more, pricey. Still gather parts for my build.
Brian

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yea, expensive.....especially when you see buildings being torn down and tons of beams being scrapped.

try calling some local demolition or construction companies. often they have beams laying around and would sell them for the price of scrap.