A hydraulic ram pulls as hard as it pushes

[GeeVee]

.... so why waste the return stroke doing nothing, on most log splitters?

I dont think it would matter if the end of the ram was a double bit "blade" or a two sided block pushing towards blades on each end? But why waste the stroke time merely retracting it? Maybe even, the moving part was a blade on one side and a push block on the other, and the ends have the right surface on each end to make it "versatile" and not waste strokes?

I do think someone has made them commercially, aimed at consumers, but I can't find one readily on the web.

 

[Del_]

A ram pushes harder on it's outstroke than it's return stroke, depending on the diameter of the rod.

I've seen videos of splitters that have like a moving knife blade going back and forth between end stops.

 

[muddstopper]

The return stroke does not have the same force as the extend stroke. Although, you are correct that the return probably does have enough force to split most wood.

 

[H-Ranch]

Well that's not quite true since the rod reduces the area for the force to "pull".

But I agree that there is some force that can be used. I think there have been several commercial units that use both directions for splitting. Tempest is the one I can remember - it was a box splitter but not sure is available now.

 

[kevin j]

There are many. Search dual direction wood splitter.

 

[dave_dj1]

Here are some hydraulic calculators for future reference.
https://www.baumhydraulics.com/Home/Page/speccalculatorsuse #1
they typically pull with less force than they push with as stated above. You lose the volume of the rod diameter.
some fun info for anyone interested
https://www.sphaera.co.uk/hydraulicPrinciples.htm

 

[siouxindian]

harbor freight had one.

 

[Brushwacker]

The one I used in the past worked about the best of any splitter I used as a 1 man operation. Shelves on both sides worked handily saving chasing pieces falling on the ground. Less bending and handling the wood. Never noticed any power problem either. It had a single stage pump. It was originally a 3 point tractor splitter, converted to a 8 horse motor with a pump from an old combine run with belt and pullies all mounted on a small trailer frame.

 

[Billhook]

 

[Bill G]

.... so why waste the return stroke doing nothing, on most log splitters?

I dont think it would matter if the end of the ram was a double bit "blade" or a two sided block pushing towards blades on each end? But why waste the stroke time merely retracting it? Maybe even, the moving part was a blade on one side and a push block on the other, and the ends have the right surface on each end to make it "versatile" and not waste strokes?

I do think someone has made them commercially, aimed at consumers, but I can't find one readily on the web.

A hydraulic cylinder does not have the same force on retraction as it does on extension. If you have ever used one in both directions you should know this. Go try to pick up the wings on a 50ft field cultivator using the retract mode.

 

[Billhook]

Box wedge splitters use the return stroke to bring the wood back saving a bit of work

 

[Bill G]

Box wedge splitters use the return stroke to bring the wood back saving a bit of work

That is a interesting splitter

 

[turnkey4099]

I have the usual one-way splitter. I have enough trouble keeping up with the one side without trying to feed both sides.

 

[nathan4104]

I have a Splitfire wood splitter. The smallest gas powered one... the nastiest wood we have here is White Birch, which can be pretty stringy. I've yet to have a piece it wouldn't split. This unit is 10 years old, and the newer version has a slightly larger cylinder I believe making it a bit slower..... this one does the 24" stroke in 4 seconds. It rarly hits 'low gear'. ove My stove likes smaller split pieces, so being able to quickly do that is a huge time savings over waiting for a retract. With a helper, you can make a good pile of wood in a hurry.

There's a lot of nice splitters out there, and a lot of ways to make firewood.....

 

[Billhook]

This one does not seem to show any weakness on the return stroke

 

[muddstopper]

There are cylinders such as this one,
that have the piston mounted in the middle of the rod. This would allow the push and pull force to be the same. Even using this method, the force would not be the same when compared with a similar bore and rod size cyl with the piston mounted on the end of the rod on the extend stroke, It would be similar to the retract force of the same bore and rod size of the end mounted rod. There is also the method of using two smaller cylinders mounted to where one cyl is pushing and one pulling to create equal force in both directions. It all depends on what one is trying to do.

 

[Del_]

The larger diameter the rod, the faster the retraction time. This is a positive with a spitter that only splits on the out stroke.

 

[Bill G]

The larger diameter the rod, the faster the retraction time. This is a positive with a spitter that only splits on the out stroke.

That depends on pump flow. If your pump flows 16GPM and your cylinder is a 4x24 it will not retract at the same speed as the same pump is contacted to a 3x24. It is simple physics (circ refs). No matter what a cylinder does not have the same force on retraction as it does on extension/lift.

 

[Del_]

That depends on pump flow. If your pump flows 16GPM and your cylinder is a 4x24 it will not retract at the same speed as the same pump is contacted to a 3x24. It is simple physics (circ refs). No matter what a cylinder does not have the same force on retraction as it does on extension/lift.

That's what I said.

It's simple physics. The square inch area taken up by the rod reduces the square inch area of the piston by the area that it takes up. Hence less push on the piston during retraction.

You've introduce various sized cylinders. That wasn't a part of the discussion but of course various sized pumps will move various sized pistons various speeds.

And there are various regeneration circuit designs.

 

[Bill G]

That's what I said.

It's simple physics. The square inch area taken up by the rod reduces the square inch area of the piston by the area that it takes up. Hence less push on the piston during retraction.

That is not at all what you said but OK if that is what you think. Go get a a 2x24, 3x24, 4x24, and 5x25 then hook them all up to the same pump and see which has the fastest retraction time. You might be amazed.