log splitter anchor baseplate

By mdlmjohnson Date 03-31-2006 23:29

In connection with a log splitter I am building, I'd really appreciate some input from any welding gurus:

I am using a 5" cylinder which can generate up to 60,000# of ramforce so I want the cylinder anchor welds to be as strong as possible.

My beam being 8x8/59# and the cylinder cross tube almost 6" there won't be sufficient room to weld all around the vertical anchors (each 1" thick) if I weld them directly to the beam. I have therefore made a base for them out of 1/2" plate 8"x10" and will weld that to the upper flange of the beam (about 1" thick). That will allow me to do a pretty burly fillet weld all around each of the anchors (after grinding a small bevel around the base of each anchor to get better penetration).

I'm planning to weld the baseplate to the beam with fillet welds across the width of the beam and, underneath, running along both edges of the beam so I'll have some 32" of fillet weld around all four edges of the baseplate.

Here's the question; would it be a good idea to drill a few holes in the base plate (inside of where the anchors will be attached) so that I can weld the middle of the baseplate to the beam with plug welds? If I do that, what size holes should I drill for the plug welds? I have an anular cutter bit that will do 7/8" holes if something that large is needed, or I can drill 1/2" holes with a normal bit. Lastly, how many plug welds would you do?

Any thoughts would be greatly appreciated.

By dschlotz (***)

Date 04-02-2006 23:32

The most strength you can possibily get will be from the weld that you put on a plate that holds your ram. That plate runs parallel to the web of the beam, and directly above it on top of the flange like a sharks fin sticking up out of the water. It should be shapped like a triangle with the straight side toward the ram yoke. Keep the holes for the pin as tight as you can to cut down on slop..
In your discription of what you plan to do you are going to a lot of extra work that gains you nothing.
If you want to see a picture of mine email me.
Dennis

By whiteyford M1A1 (**)

Date 04-05-2006 01:07

Howdy
dschotz is pointing you in the right direction. Your cylinder should fit onto a 1" thick vertical lug. The strength your looking for is on the same plane as the beam web, directly above the web to flange transition. I just did a 25 tonner with a 6" triangular mounting lug 1" thick with a double bevel and 1/2" fillet. It's Bulletproof and it splits wood!
Good luck
Whiteyford M1A1

By swnorris (****)

Date 04-05-2006 13:51

Plug welds wouldn't hurt, but they're not necessary. 32" of 1/4" fillet welds are good for almost 119,000 pounds of stress (.928 x 4 x 32). If you increase to 5/16" fillet welds, the welds are good for 148,480 pounds of stress (.928 x 5 x 32). However, if you tie the the two welds across the inside flange to the two welds across the outside flange, you may create a notch, and, you don't want to do that.

By CHGuilford (****)

Date 04-05-2006 16:41

To all respondents,
I'm not trying to rain on anyone's parade and I mean this in a respectful way but I just have to ask:
Are any of you qualified engineers? Have you seen any details other than what is described in the original post?

I don't have a good picture of the application, I don't have my own log splitter, and I'm not an engineer, so maybe I'm a bit overcautious on this, but I would be careful with advice if there could be any question on the end use. What I do know is that the engineers I have dealt with on weld strength issues ask me a lot more questions on what I intend to do than I have seen answered here.
Again, not trying to be negative or disrespectful, just careful.

Chet Guilford

By swnorris (****)

Date 04-05-2006 17:37

I agree. I'm not a qualified engineer and I don't know the stresses that will be imposed on this weld application, or any other weld application, but I do know fillet weld strengths. I just mentioned what the welds are capable of supporting based on the 32" of fillet welds that the poster has intended on using, and I caution not to tie the four welds together, as they could create a notch and initiate a failure. Plug welds are used to transmit shear forces in lap joints, to prevent buckling of lapped parts, and to join component parts of built up members. I can't imagine where using plug welds would gain anything, especially if the fillet welds will suffice, but I did mention that they wouldn't hurt anything. As you mention, there are other considerations.

By mdlmjohnson Date 04-05-2006 18:18

Many thanks for all the helpful responses. The joint between the beam and the base plate is essentially a lap joint as the base plate is wider than the beam and lies flat on top of it.

The fillet welds across the width of the beam are, of course, perpendicular to the direction of the stress created by the hydraulic cylinder pushing a log against the splitting wedge, which is parrallel to the web. the fillet welds between the underside of the base plate and the edge of the upper flange are parrallel to the stress and thus, as I understand it, more effective in securing the base plate. Not being an engineer, either, and a novice welder as well, I was not confident that the fillet welds would be sufficient to resist the shear stress of the baseplate against the beam, so I thought that additional shear resistance could be provided by a few plug welds.

It has been suggested, by a poster on another welding board, that I use a couple of 2"x6" slot welds for this purpose and that makes sense to me as it would another 24" of fusion parrellel to the web.

By billvanderhoof (****)

Date 04-06-2006 07:05

Another "not an engineer" comments. I'm not certain that this is a shear limited situation. Other failure possibilities are failure in tension at the cylinder end of the vertical piece or the plate that it is mounted on or in the middle of the weld that secures the plate to the beam. Also possible is that the web of the beam cripples under the end of the vertical that is away from the cylinder. In both cases the forces are the couple that prevents the vertical from rotating back under load.

I don't see this as a system that can store a great deal of potential energy so an explosive failure where parts go flying through the air is improbable (after initial proof testing).

Stay with lower strength fillers like 7018 (less likely to be brittle). Be extra careful at first, I would put a log in crossways and load it up till the relief valve operates as a test while standing somewhere safe. Watch for cracks to form and repair or reinforce as needed.

Bill

By mdlmjohnson Date 04-06-2006 18:58

Thanks, Bill for your very helpful suggestions. This is exactly the kind of thing that I, as a newcomer to welding, do not know on my own and am learning through the generosity of you and others here.

By dschlotz (***)

Date 04-09-2006 13:35

Chet,
I did a lot of research before I built my wood splitter. I wanted to be safe. There are two basic types. #1 A wedge is attached to a ram and the wood to be split is pushed toward a stop of sufficient size and mass to resist the force of the ram and the wood is thus split. #2 The wedge becomes the stationary member and the ram pushes a movable platen, with the wood to be split, toward the wedge. These were the two types I saw that were commercially built.

The danger in using such equipment is crushing body parts between the two splitting members, however configured. Also wood can be launched in most any direction because of the force required in splitting.

Both splitting members can be attached on the flange CL of a WF beam at the end of the cylinder stroke. Beam is what you see used for wood splitters because of its ability to resist bending when used for this application. Please try a Google search for "log" or "wood" splitters and take a look at wide variety of sizes and shapes.

Respectfully Dennis