Undersizing log splitter cylinder

[anesthes]

I have a question for you hydraulic pro's.

I'm just about done building my log splitter. Using a factory 4" I beam with welded wedge I got on trade.

Pump is Speeco 11gpm 2 stage. For now, driven by a 5hp tecumseh engine.

Valve has the following specs:
Single spool, Open center.
· Max pressure rating: 3500psi.
· Relief valve set at 3000psi but is adjustable.
· Working ports 1/2 NPT.
· In/Out ports 3/4 NPT
· Detent Pressure set at 700 psi but is adjustable.
· Compatible with most splitters (SpeeCo, MTD, Brave, Swisher etc)
· Screw off end cap for easily detent pressure adjustability

The cylinder however is undersize based on pump recommendations. It is 3" bore by 18" stroke. 3000psi operating pressure. I'm guessing around 13ton?

I'm assuming that, with the relief set at 3000psi on the valve, I'll simply have less splitting power than my pump is capable of?

I just don't want to create a scenario where I blow a hose and cause a safety issue.

-- Joe

 

[cmhyland]

I have a question for you hydraulic pro's.

I'm just about done building my log splitter. Using a factory 4" I beam with welded wedge I got on trade.

Pump is Speeco 11gpm 2 stage. For now, driven by a 5hp tecumseh engine.

Valve has the following specs:
Single spool, Open center.
· Max pressure rating: 3500psi.
· Relief valve set at 3000psi but is adjustable.
· Working ports 1/2 NPT.
· In/Out ports 3/4 NPT
· Detent Pressure set at 700 psi but is adjustable.
· Compatible with most splitters (SpeeCo, MTD, Brave, Swisher etc)
· Screw off end cap for easily detent pressure adjustability

The cylinder however is undersize based on pump recommendations. It is 3" bore by 18" stroke. 3000psi operating pressure. I'm guessing around 13ton?

I'm assuming that, with the relief set at 3000psi on the valve, I'll simply have less splitting power than my pump is capable of?

I just don't want to create a scenario where I blow a hose and cause a safety issue.

-- Joe

Joe,
as long as the relief valve settings are under 3000 psi you'll be fine. I have a splitter with the exact scenario... I have the Powerhorse 13 ton splitter.... You'll be amazed what a 13 ton splitter can do... I haven't found anything I couldn't split without a bit of finesse...

Regards,
Chris

 

[Maxwelshouse1]

You gain speed by having a smaller cylinder; the flip side is that you loose power (tonnage). My free Android hydraulic calculator app puts it at 21206# of force (10.6 ton), which is reasonable for a lot of basic log splitting.
As for the fear of a broken hose, I agree with CMHyland. I'm guessing the above scenario had more to do with air in system. That is a pretty big pump for a small cylinder, which is not a bad thing, but you should have 11gal hydraulic fluid.
My 16GPM pump lacked enough hydraulic fluid to run effectively the first test run. Put another 5 gallons.. and you couldn't slow it down! It's a good feeling stocking up wood for a stormy day! The cold is a comm'in.

 

[anesthes]

Thank you guys!

Another rookie hydraulic question.

The ports on the cyls, valves, etc are all NPT according to the documentation.. I know on automotive applications, we put an adapter and run -AN fittings/hoses for our hydraulic lines (i.e hydroboost, power steering, transmission, etc).

Should I expect the hoses commonly sold at tractor supply to thread directly into the cyls, valves, etc or should I expect to have to get some sort of fittings ?

Thanks again!
-- Joe

 

[muddstopper]

I have never used AN fittings so I dont know if they have the pressure rating you need for high pressure hydraulic systems. Some one else can chime in on that. The NPT are common on hydraulics and tsc does sell them. As long as your cyl, valves etc, are NPT and you buy the proper size, fitting shouldnt be a issue. I aint really a NPT fitting guy. What I normally do is screw in a NPTxJIC fitting and use JIC hose ends on my hoses. I guess I always go that way because JIC is normal for hoses at work and I usually save hoses that have blown and bring them home for my project use. Most of these hoses usually blow at the fitting so its a matter of just cutting off the blown end and replaceing with a new fitting. Of course the hose ends up being shorter and unusable for the system it came off of originally, so instead of tossing, I save.

 

[Maxwelshouse1]

I agree with muddstopper. I'm not a big pipe-thread fan, but it is the platform to build upon. I too love JIC, which gives you the flexibility to tighten your hose in the "relaxed" position. JIC is quicker to install/remove without thumbing with tape, dropping it into the mud, etc. Warning of the light-wallet guy-hoses at the hose-house is VERY expensive! I really wished I had thought ahead and ordered these online at the hydraulic Surplus Store below. I could have saved a lot of money. I think I paid $75 for one of my hoses! Yikes.


Good luck and keep us posted.

Surplus Center - Hydraulics, Engines, Electrical and More

 

[J_J]

Here is some data on AN fittings.

AN" (Army-Navy) Sizes were established by the Aerospace industry years ago and were designated O.D. of the rigid metal tube that each size fitting is used with.

AN fittings are a flare fitting, using 37° flared tubing to form a metal-metal seal. They are similar to other 37° flared fittings, such as JIC, which is their industrial variant. The two are interchangeable in theory, though this is typically not recommended due to the exacting specifications and demands of the aerospace industry.

These two fittings function the same, they look the same, AND the industrial version is much less expensive to manufacturer. The problem is that the industrial version is 40% weaker. "A significant improvement in fatigue life is attained with the use of MIL-S-8879 thread when compared with the MIL-S-7742 thread." DAC (Douglas Aircraft Corporation) Design Handbook 1.5.10.1

Pressure Rating: 1500 PSI - note: crimp-on fittings are recommended for applications over 500 PSI.

http://www.anfittingsdirect.com/pro...=1615&osCsid=d77f70d02bd3aca0d0baf6654202d973

So far, I have not found any 3000 psi AN fittings.

 

[BukitCase]

BTW, a 3000 psi 3" cylinder will only generate 21,205 pounds of push - it would take 3680 psi to get 13 tons... Steve

 

[anesthes]

Here is some data on AN fittings.

AN" (Army-Navy) Sizes were established by the Aerospace industry years ago and were designated O.D. of the rigid metal tube that each size fitting is used with.

AN fittings are a flare fitting, using 37ｰ flared tubing to form a metal-metal seal. They are similar to other 37ｰ flared fittings, such as JIC, which is their industrial variant. The two are interchangeable in theory, though this is typically not recommended due to the exacting specifications and demands of the aerospace industry.

These two fittings function the same, they look the same, AND the industrial version is much less expensive to manufacturer. The problem is that the industrial version is 40% weaker. "A significant improvement in fatigue life is attained with the use of MIL-S-8879 thread when compared with the MIL-S-7742 thread." DAC (Douglas Aircraft Corporation) Design Handbook 1.5.10.1

Pressure Rating: 1500 PSI - note: crimp-on fittings are recommended for applications over 500 PSI.

http://www.anfittingsdirect.com/pro...=1615&osCsid=d77f70d02bd3aca0d0baf6654202d973

So far, I have not found any 3000 psi AN fittings.

Heidts, Fragola make 'em up to 3500 PSI. We use 'em for hydroboost. I keep forgetting that 'JIC' is the industrial version of AN, whenever I see them like on my bobcat I just call them AN as it's what I'm used to. But yeah, I wasn't sure if the hydraulic hoses commonly sold were NPT or JIC. They appear to me NPT.

But yeah, aluminum AN fittings are rated to 250psi in most cases (fuel, coolant) where the steel fittings are typically 1500 but the specialty fittings are 3500.


Thanks guys! Hopefully have this thing splitting wood by next week.

-- Joe