hydraulic cylinder question

[firemankris]

I plan on buying the 4x24 cylinder for the splitter I'm building this week.My question is, whats the difference in output between the 1 1/2" rod and the
2" rod? Is it going to make a big difference? I don't mean to sound stupid,But I know the only stupid question is the one you don't ask. Thank's for the input in advance.

 

[Patrick62]

strength

My 5" cylinder uses a 2 inch rod, but I also have a smaller 4" that uses a 1 1/2 inch rod. Figure that the guys that designed your cylinder, spec'd the rod strong enough for max pressure (2500??) on the cylinder.

-Pat

 

[mga]

the tons of pressure would be the same. the only advantage is it might be slightly stronger...meaning less likely to bend.

however, that 1.5" should do the trick for you as long as your slide/guide is well anchored to the beam and does not allow for any movement of the ram/rod. this is how i did mine. i got the idea from the guys here and how they built solid ram guides.


http://s89.photobucket.com/albums/k228/mga_01/?action=view&current=DSCF0207.jpg

 

[stumpguy]

the 2" rod will have a slightly faster return stroke time.

 

[Butch(OH)]

A straight rod is real strong, one that is bent is weak. You don't want a nice tight fit like we would normally call good craftsmanship between the cylinder clevises and the mountings. You want to leave some slop, how much is needed is determined by your guides and how much things flex under pressure. Your eyes should be focused upon that cylinder rod when you begin to use the splitter. If it is being forced in any direction while under pressure you need to relieve it by opening up the mounting tolerances or fixing flex or slop in the guides.

 

[Finnbear]

When building a splitter always go with the larger diameter rod if you can spend the extra $$$. The extra diameter of the larger rod gives you a faster cycle time on the return stroke since it displaces more oil than a smaller diameter rod. It also gives you a bit of extra insurance against bending the rod on the push stroke should you encounter something extra stubborn. Theoretically, the samller rod should be capable of pushing whatever the cilinder is rated for but in real life they do sometimes get bent so this isn't always true.
Finnbear

 

[CylinderService]

Not all cylinders are rated by their manufacturers for the full pressure in the longer strokes. I don't believe a 1 1/2" rod in a 24" stroke would be rated for 2500 PSI by a reputable manufacturer. Prince uses 1 3/4" high-yield rod for their tie rod cylinders, and then rates them for 3000 PSI. They used a standard quality 1 3/4" rod for their 2500 PSI line. Their welded cylinders use 2" standard rod.
I agree with Butch about leaving your rod-to-pusher connection loose, and making the pusher well guided. It should never put any side stress on the rod.
As for "figuring" that the cylinder sellers must have made it good enough - when you buy cheap, you get cheap. There are many grades of rod, but they all look good with chrome. When we cut or machine old rods, we find tremendous differences in hardness and toughness.
While I'm sure there are plenty of logsplitters with 1 1/2" rods still working, there are also plenty of them which have been replaced because the rod bent. A lot of them came to us for their second cylinder.
The only thing more expensive than buying a good cylinder is buying a cheap cylinder, throwing it away, and then buying a good cylinder!

Don

 

[GlennG]

The only thing more expensive than buying a good cylinder is buying a cheap cylinder, throwing it away, and then buying a good cylinder!

Don

Excellent points....but the above quote is a great lesson in economics no matter what the product. It took me a few years to learn the hard way that cheap is expensive.

I applauld all that build their own splitters but I purchased my splitter new because I learned I could not build one any better or for less money.

My hat is off to those that do build their own splitters

 

[GlennG]

Also I had to purchase new because I need it to have all the saftey and warning stickers. I rent this machine to customers. So far the machine has earned 2/3rds of its purchase price.