3 1/2 in bore cylinder on wood splitter

[AKKAMAAN]

3550, I,m using a HF 6.5 horse motor with a 11 gpm 2 stage pump and cycle time is about 13 seconds out and just a tad slower back but very useable.It,s never failed to split red oak and I even put a twist in my wedge so no complaints power wiseDave

Just curious crusty 1....
Do you use 3/8" hoses to the cylinder??

 

[LD1]

Just curious crusty 1....
Do you use 3/8" hoses to the cylinder??

I thought that seemed a bit slow but I didnt say anything though.

 

[AKKAMAAN]

I thought that seemed a bit slow but I didnt say anything though.

Cylinder should have a faster travel on retract...at 11gpm retract speed should be 5.87 ips vs 4.40 ips on extend. Note that return flow out from capped side will be 33% larger, 11 x 1.33=14.67gpm, and if too small hoses are used the the back pressure will be so high that low stage could kick in on pump when retracting...3/8" hose will make 13.67gpm run at 42.6ft/sec (20 ft/sec is max recommended in most nomograms), could be enough to make pump pressure raise above setting on pump, which is 400-900psi....

 

[J_J]

What size ports are on the Energy log splitter valves? If the cyl has a 3/8 port, would you use 3/8 in hose or 1/2 in hose and adapt the hose fitting to the cyl?

If the 16 GPM HALDEX/BARNES 2 STAGE HYD PUMP has a max rating of 3000 psi, why would you set the log splitter valve relief valve above that?

I believe the 3000 psi on the max pump psi is at 4000 rpm, which most small engines are govern to run at 3600 rpm.

# Second stage 4 GPM @ 2500 PSI
# 16 GPM @ 3600 RPM

The OUT port of the pump is 1/2 in, so there is no reason to use lager hose.

 

[AKKAMAAN]

What size ports are on the Energy log splitter valves? If the cyl has a 3/8 port, would you use 3/8 in hose or 1/2 in hose and adapt the hose fitting to the cyl?

depends on the flow, Yes, if fitting is creating turbulent flow, then I would makes sure flow get laminar in the hose...thats done with a larger hose...

The OUT port of the pump is 1/2 in, so there is no reason to use lager hose.

At the end of the day, maybe "no reason" practically, if it is a very short hose, but it still have a impact...

This document (metric units) shows how to calculate pressure drop in a hydraulic line...
Reynolds number, "R", is the indicator of turbulent flow (turbulent flow causes pressure drop). R is a product of orifice diameter, fluid velocity and and kinematic viscosity.

When calculating the pressure drop, ∆p = vｲ ﾗ f ﾗ L ﾗ ρ/2D, one can see that length, "L", or orifice (fitting, hose, elbow etc) is direct proportional to the pressure drop...(ρ = fluid density, f=friction factor 64/R, v=velocity, D is inside diameter), so continuing the 3/8" size throughout the entire hose, will make more pressure drop than with large size hose....

So "theoretically" there is always a benefit with a larger hose than port size....have a practical impact?? Calculate it or use a laser temp gauge....that will tell how big impact there is....

I the electric field, we all know how resistor in series, add resistance to each other, so do "resistors" in a hydraulic line (Voltage is the electrric eqvivalent to pressure in hydraulics) ......port+adapter+fitting+hose+fitting+adapter+port...etc....so if port is small there is "no reason" to make hose smaller

Electric-Hydraulic analogies

 

[crusty 1]

Just curious crusty 1....
Do you use 3/8" hoses to the cylinder??

I belive their 1/2 inch but I,d have to measure.Will try to do that today

 

[crusty 1]

Guy,s I'm not sure if it affects speed but my lines were reversed as it was safer for me to pull on the handle than to push it,my balance isn't the best.I also run the engine at 1/2 to 3/4 throttle because I can't work any faster than thatDave

 

[LD1]

Guy,s I'm not sure if it affects speed but my lines were reversed as it was safer for me to pull on the handle than to push it,my balance isn't the best.I also run the engine at 1/2 to 3/4 throttle because I can't work any faster than thatDave

I think the only difference in reversing the hoses at the valve is the detent.

Does yours have a detent? They normally detent in the reverse position only and you have to hold constant pressure on the extend stroke. If you reversed these, being able to detent in the forward position creates a whole other saftey issue.

And yes, running the motor slower will slow down the pump. If the pump is an 11gpm pump, that is usually rated at the motors WOT setting of ~3600rpm. If you are only running 1800rpm, you have cut the flow in half, down to 5.5gpm.

I have also read on some other forums that it is harder on the motor to run them at reduced throttle. I cant remember the specifics, but it was reputable members in it indusrty mentioning that.

 

[J_J]

crusty 1,

I don't believe the relief valve works in reverse hose set up. Are you sure the reverse hose thing did not cause harm to the valve. The guy talking about the Energy valves, had some things to say about pressure on the seals, etc.

Did you think the log splitter was operating normally? There should have been some indication that something was not right.

As far as hose size, I don't believe increasing the hose size is warranted on a short hose situation like a log splitter. Maybe long run of hose. Besides that, they are trying to keep the cost as low as possible. Saves on hose and fitting price, to keep things equal.

If they did everything technically correct, the cost of things would increase.

I am not a math expert, but do understand resistance, turbulent flow, velocity, etc. The engineers get paid to figure out all the particulars.

It is just amazing that the number of home built log splitter systems are out there, and still working good.

Has anyone had the pressure on a two stage pump up around 3400 psi, if so, what were the circumstance. I wonder about the warranty on the two stage pumps.

IMPORTANT!!! Pressure at "T" (return) port in excess of 100 psig (7 bar) may interfere with proper operation of valve.

 

[shansen]

You are right JJ, the internal relief valve will not operate if the inlet & outlet hoses are turned around. If the A & B cylinder work port hoses are turned aroud, the valve will detent while the cylinder is extending creating a DANGEROUS SAFETY HAZARD.
Be certain the pump outlet port is connected to the valve IN port and the valve OUT port retruns to the reservoir. Valve B port must be connected to the base end of the cylinder and the valve A port must be connected to the rod end port of the cylinder.
The valve control lever can be assembled to make the cylinder travel in the desired direction pushing or pulling on the lever.