Log splitter slide rebuild - how free should it be?

[sw18x]

I'm in the middle of rebuilding the pusher and slide for my log splitter. Currently, I have 1/16" washers between the sandwich piece and the pusher base to give me enough clearance to slide the pusher free on the top plate. This is only a mock up, because I have some .030 (about 1/32") sheet metal cut to the dimensions of the sandwich (2X10") which I plan to drill and use for a spacer instead of the washers, but is .030 enough? How much clearance should I shoot for here? She slides real nice now at 1/16" clearance, and one school of thought would be keep it on the free side to avoid binds, but it also seems to me that the closer you run on the low side of tolerance then the pusher plate will sit flatter if it tries to tilt back under load and the pressure will be more evenly distributed. Thanks in advance for your input.

 

[Zeus103363]

I'm in the middle of rebuilding the pusher and slide for my log splitter. Currently, I have 1/16" washers between the sandwich piece and the pusher base to give me enough clearance to slide the pusher free on the top plate. This is only a mock up, because I have some .030 (about 1/32") sheet metal cut to the dimensions of the sandwich (2X10") which I plan to drill and use for a spacer instead of the washers, but is .030 enough? How much clearance should I shoot for here? She slides real nice now at 1/16" clearance, and one school of thought would be keep it on the free side to avoid binds, but it also seems to me that the closer you run on the low side of tolerance then the pusher plate will sit flatter if it tries to tilt back under load and the pressure will be more evenly distributed. Thanks in advance for your input.

I didn't include this in my other reply to your post. I have a friend who's got some design software that will show stress when things are put into motion. Kinda cool how it works. He ran a simulation on something simular to what you got going there with the pusher plate. His thoughts after running a simulation was the pusher plate is under far more stress than having a wedge on the cylinder rod. He said it has something to do with when the wedge goes through the wood the stress point is more evenly distrubuted throughout the wedge to the mounting plate. He also said a pusher plate has to be way more beefed up because it is pushing almost at the same exact spot constantly, and the stress point is at the same location. Right at the bottom of the push plate where it makes contact with the beam. This is why far more push plates get bent, and when the wedge is on the cylinder rod the wedge doesn't get bent up as often, but anything can happen. Seems like as far as the gap, I think you would need as little gap as possible, and for it to be as smooth as possible too. I even went as far as looking at putting cam beaings under the beam flange so the plate would "roll" down the beam instead of sliding down. As you mentioned, too much gap causes the plate to "pinch" as it us pushed back under the stress load, which could cause the bottom plate to bend. What you have there looks pretty beefed up. You may have to put it together and try it out and see how much play you end up with. Just remember after painting, it will tighten up, but then after it is run some it will loosen back up.

 

[wndwlkr]

The setup you have in your pic looks real good. I'd run it like that & see what you think.

 

[Steve2910]

Mine's well worn, & all of the bolts are bent. Funny thing is, all that slop seems to help it weave it's way through twisty grain. That said, my wedge is on the cylinder, so my experience probably doesn't apply to your situation.

 

[blades]

real life - if the round is the same size or smaller than push plate not much stress other than what it takes to pass round through wedge. If the round is greater in dia. than the push plate a lot of stress is going to be at the top of the push plate trying to peal it back. This why I advocate a push plate that is twice as long as it is high with reinforcement from the top of the plate to the rear most edge, this just about impossible to do for the wedge except to make it very long or a two stage affair in the vertical plane. (Sloped wedges will reduce stress but are somewhat unsafe as they can allow a round to squirt out in the vertical with the leading edge low. In reverse to much stress is transmitted to the attachment point due to captivation.) Which ever piece is fixed to the beam will transmit a considerable amount of that force into the beam. Computer modeling is great, but if the parameters are not set up correctly it can give you a false sense of security. Just a old mec whos been around the field a few dozen times.

 

[Whitespider]

My thinking goes contrary to most everyone else; I don’t understand the push plate design on these splitter builds. Unless the round is cut perfectly square, a large, flat plate will put immense stress on the ram, plate, slide and beam… unnecessary and wasted force. If you can keep all the force confined to a smaller area, directly inline with the ram, the stress on the slide and beam can be near eliminated and the force is more efficiently applied. More times than not my slide will be vibrating and rattling as the round is being split (i.e. zero stress on the slide, it’s just floating). Notice the cylinder is front mounted so it won’t try to lift or shift sideways and the push plate swivels to “grab” rounds cut at an angle. It doesn’t matter if the round is 6-inches or 30-inches in diameter, all the force remains confined to a small area, relatively directly inline with the ram.

 

[YarraValleyDude]

I recently rebuilt mine too, got sick of wearing out the slides:bang: I use mine professionally............So have some experience here.

Clearance wise your 16th of an inch or 1.5mm is just about perfect IMHO.

One thing i learned along the way is that you can't make it too long, mines 13" long in total now and it dosn't matter where the plate strikes the round, it just pushes straight and all the force is where you want it.

Cheers
Rob

 

[Whitespider]

...got sick of wearing out the slides... you can't make it too long, mines 13" long in total now and it dosn't matter where the plate strikes the round, it just pushes straight and all the force is where you want it.

It does not push "straight"... and my little 4-inch, 3/16 thick slide ain't bent or worn out in over 25 years of service.

 

[YarraValleyDude]

It does not push "straight"... and my little 4-inch, 3/16 thick slide ain't bent or worn out in over 25 years of service.

Ok, in my instance the ram is rear mounted so the rod will flex sideways especially in twisted wood if the slides are sloppy.By sloppy i mean 1/4" play....not good. I guess this depends on what wood your splitting.......
With a longer pusher there is zero tendency for that plate to twist sideways, this is what wears the slides out in my case.

In regard to your pics it doesn't matter how the round is cut as it will always be flat against the pusher but the end on the wedge will go where it wants to depending on the position of the round in relation to its cut.
In a perfect world all rounds would be cut even as in a wood processor situation.

Guess it depends on what your splitting too.........Large hardwood rounds(24-36") will kill any splitter eventually i can vouch for that!