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  #11  
Old 10-01-2020, 08:34 PM
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toprecycler toprecycler is offline
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Originally Posted by JBFab View Post
I had a feeling a trip to Petoskey might be part of this build. If I give you some desired dimensions could you quote it for me? Another thought I had was if we bought a "stock" cylinder with a smaller rod maybe you guys could modify the end cap and replace the rod with a larger one cheaper than building a new one all together.


Modified existing cylinder could be an option too. If it comes to it, I will get you the number of the guy that does the quoting.


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  #12  
Old 10-01-2020, 08:35 PM
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Originally Posted by digger doug View Post
Use a separate smaller cylinder to push the big cylinder back, the big cylinder
dumps to tank (and sucks from tank) during this.
That actually makes sense.
A large single acting cylinder pushed back fast by a 2" cylinder.
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  #13  
Old 10-02-2020, 07:01 PM
bunkclimber bunkclimber is offline
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Default Large rod cylinders

why not use a COMBINATION of a 4"bore double acting cylinder and a 1" or 2"bore cylinder; plumb BOTH extend cylinder ports to the 'A' port on the valve and only the 1"/2"cylinder port to the 'B'port for retract..added tonnage on extend/split but the quick retract time like Gerry said..then you get your 5" bore for splitting at a common-off-the-shelf 4"bore cylinder price..
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  #14  
Old 10-02-2020, 07:15 PM
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I just don't see the sense of messing with the concept. Retract speed is always far faster than extension. Just spec a little heavy on the GPM for the pump and let nature take it's course. How much reduction in cycle time do you think will actually justify a $2000 custom cylinder. If you want to speed up retract use an oversize return port on the cylinder just going from 3/4' to 1" along with going with excess pump capacity will push that ram back pronto. Just my 2 cents. The smaller volume needing to be expelled from around the rod on the extend side should balance out pretty close
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Last edited by Whitetrash; 10-02-2020 at 08:06 PM.
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  #15  
Old 10-02-2020, 09:52 PM
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Originally Posted by Whitetrash View Post
I just don't see the sense of messing with the concept. Retract speed is always far faster than extension. Just spec a little heavy on the GPM for the pump and let nature take it's course. How much reduction in cycle time do you think will actually justify a $2000 custom cylinder. If you want to speed up retract use an oversize return port on the cylinder just going from 3/4' to 1" along with going with excess pump capacity will push that ram back pronto. Just my 2 cents. The smaller volume needing to be expelled from around the rod on the extend side should balance out pretty close
Pretty much my thoughts too. A few tweaks like those mentioned above will get the cylinder retracting pretty quickly. The cylinder always retracts with no load so it's gonna be quicker right from the start...
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  #16  
Old 10-03-2020, 09:25 AM
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Originally Posted by LKeithR View Post
Pretty much my thoughts too. A few tweaks like those mentioned above will get the cylinder retracting pretty quickly. The cylinder always retracts with no load so it's gonna be quicker right from the start...
Most wood splitters use a two stage pump with high volume at low pressure, shifting to low volume at high pressure as the load gets heavier.
This would and does mean, fast retraction.
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  #17  
Old 10-05-2020, 05:20 AM
bunkclimber bunkclimber is offline
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Default large rod hydraulic cylinders

Surplus Center has some decent offerings in their large bore, large rod listings, some 6" and 7" bore with 5"dia rods, double acting, less than $1K FWIW

https://www.surpluscenter.com/Hydrau...er-9-11449.axd
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