4 way wedge on home build splitter

[Jags]

After setting the relief pressure I was curious at restriction pressure and put it at return port of the control valve to gauge no load pressure. The gauge was a 5000 PSI so the difference between 50 and 75 would be tiny. All I cared about was that the pressure was low. And it was.

Folks, to clarify my point... I am not suggesting using small hoses, fittings, etc is the right thing to do. I am simply saying in real life of a log splitter it is not nearly as detrimental as some believe it is. Unless it is severely restricted this is not going to be the "aahaa" moment that noticeably changes the speed of your splitter.

 

[DonTee]

Awesome. Thanks for the info. I figure since I’m changing all the parts on this splitter anyways, I can build it how I want to.

With the old setup the reservoir, cylinder, and lines only got warm. The pump and reservoir are kind of one unit, so it’s hard to hold your hand on the pump to see about temp. I should’ve checked it with the infrared thermometer...

I watched a video on the Bells super splitter. One of the commenters said it’s used to make the pieces of log smaller for a wood processor or smaller sawmill. I have seen where people split smaller logs down for fence posts/rails. But usually those are much smaller logs.
The Amish like to do that with locust logs.

 

[Isaac Carlson]

A gauge on the return port is only going to show return pressure, not circulating or line pressure. The gauge needs to be after the pump and before anything else. Put the gauge right after the pump and you will see a bunch of pressure.

 

[Jags]

If it goes in it has to come out. In the neutral position the input side of the valve body and the output side of the valve body assuming the ports are identical should have exactly the same pressure

 

[DonTee]

I got the adaptors and hooked up the cylinder today. Ran it back and forth a few times with it not mounted to anything.

It seems faster than the old cylinder. But I only ran it at idle so I don’t know.

 

[Ashful]

I got the adaptors and hooked up the cylinder today. Ran it back and forth a few times with it not mounted to anything.

It seems faster than the old cylinder. But I only ran it at idle so I don’t know.

It should be, if my memory of old cylinder diameter is correct. Less fluid volume to fill = faster cycle at same GPM.

 

[DonTee]

I’m thinking about ordering the 1” thick brackets I posted earlier. The only issue with them is the hole for the pin is only .9”

Otherwise I’ll have to find a source for some thicker than 1/4” steel. Maybe my welding friend has some stock laying around. I’ll have to ask him.

Anyways I really want to get the splitter up and running again. My big pieces of wood are starting to pile up.

 

[Ashful]

I’m thinking about ordering the 1” thick brackets I posted earlier. The only issue with them is the hole for the pin is only .9”

Otherwise I’ll have to find a source for some thicker than 1/4” steel. Maybe my welding friend has some stock laying around. I’ll have to ask him.

Anyways I really want to get the splitter up and running again. My big pieces of wood are starting to pile up.

You should have a steel yard local to you, although many only work in 10 or 20 foot lengths, and charge for each cut. For small amounts, like your brackets, McMaster usually works. They have any thickness you need, along with the drill bit and/or pin you're liking going to want, too.

Here's a 1 ft piece of 3/8" x 3", which would likely work for your brackets:

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[Isaac Carlson]

If it goes in it has to come out. In the neutral position the input side of the valve body and the output side of the valve body assuming the ports are identical should have exactly the same pressure

Nope. If you put a gauge at your well tank and it reads 40 psi, and then put a gauge at the end of a hose with the hose on, the reading at the end of the hose will be about 20 lbs because of friction/restriction. A gauge only tells you the pressure at that point in the system. Putting the gauge on the return line only tells you how much pressure it takes to push the fluid through that line, NOT the rest of the system. The only way to test system pressure is to place the gauge right after the pump because the pump makes the pressure, and the pressure will drop as you move away from the pump because of restriction and friction losses. A gauge on the return line will always read about the same, except when in the high pressure stage or when the relief is open, because the flow drops to about 25% of normal in high pressure in high pressure mode. In that case your gauge would read 8-10 psi when the rest of the system is at ~3,000 psi. So, like I said, put the gauge at the pump and see how much pressure it takes to run all that fluid through a series of 3/8" ports/fittings/hoses. It's a lot more than you think. Count the fittings and hose ends in the circuit, now multiply that by 30-70 psi for each one. That should give you an idea of how much pressure the pump has to make just to move the fluid, assuming 11 gpm in 3/8 lines/fittings. If it is 16 gpm, it will be MUCH higher.

Check this out:

Hydraulic Basics

Learn about Fluid Power Basics with this Hydraulics Lesson. LunchBox Sessions is a new take on online industrial training, full of interactivity, used by individuals, schools, and companies around the world.

www.lunchboxsessions.com

 

[Ashful]

We are in 100% agreement on that, Isaac. Basic circuit theory, you can even apply ohms law and calculate pressure drops according to resistivity (R = rho*L/A), as the analog to viscosity. The math is all the same, at the first order, with the exception that viscosity is a more complex phenomenon than a constant resistivity (second order effects).

But I'm still not seeing much support for your claim that 1/2" lines are insufficient for 16 GPM in a log splitter application, and that 3/4" lines are warranted for this flow rate. That is my only point of contention, with all that you have posted. We are in agreement on everything else.

 

[Jags]

The hydraulic basics post above is exactly what I am trying to say. Maybe I will try a different way...
Flow rate from a positive displacement pump stays constant (that’s the GPM rating of the pump). Flow velocity can change due to restriction/friction, etc. Increased velocity increases heat and pressure but NOT flow (fluid is not compressible). If a gallon of oil is pumped out of the output of the pump, a gallon will come out at the other end (what goes in, must come out). Even if PSI and HEAT increase - you will not change the rate of flow (or the GPM) of the system. Manage the heat and pressure and everything else just works.

A well pump using a centrifugal pump and compressed air head is a different discussion.

 

[Isaac Carlson]

Ashful-
That is what the charts and stuff call for. As we both know, most splitter pumps, cylinders, and valves have 1/2" ports, so 3/4" lines would be useless. 1/2" lines would be the bare minimum AND the only choice due to port size.

If going higher than 16 gpm or using a large rod cylinder, everything would need upsizing. That's why the homemade splitters on youtube with 20+ gpm pumps have 3/4" lines, big spools, and dump valves....and they still have temperature and pressure problens. One guy had over 500 psi return pressure because his system was STILL too small.

Most splitters will be fine with 1/2" lines because they use standard cylinder configurations and 11-16 gpm pumps. It's a sweet spot that works and is affordable. I was going to move up to 20+ gpm, but I would have to build a whole new splitter and the cost of new components was about 10k. I'll run my current splitters and be happy doing it.

If you want a faster cycle time with 1/2" lines and a limit of 16 gpm, the only thing left is a smaller cylinder(the best option) or a large rod cylinder with a dump valve for the 36 gpm return flow (you would be making a lot of heat with this one).

 

[Ashful]

Ashful-
That is what the charts and stuff call for. As we both know, most splitter pumps, cylinders, and valves have 1/2" ports, so 3/4" lines would be useless. 1/2" lines would be the bare minimum AND the only choice due to port size.

If going higher than 16 gpm or using a large rod cylinder, everything would need upsizing. That's why the homemade splitters on youtube with 20+ gpm pumps have 3/4" lines, big spools, and dump valves....and they still have temperature and pressure problens. One guy had over 500 psi return pressure because his system was STILL too small.

Most splitters will be fine with 1/2" lines because they use standard cylinder configurations and 11-16 gpm pumps. It's a sweet spot that works and is affordable. I was going to move up to 20+ gpm, but I would have to build a whole new splitter and the cost of new components was about 10k. I'll run my current splitters and be happy doing it.

If you want a faster cycle time with 1/2" lines and a limit of 16 gpm, the only thing left is a smaller cylinder(the best option) or a large rod cylinder with a dump valve for the 36 gpm return flow (you would be making a lot of heat with this one).

Agreed. In fact, I had started my own 23 GPM build, but abandoned it for a combination of reasons, primarily:

1. I couldn't find affordable 4" cylinders with ports larger than 1/2".
2. I would have had to cut the bung out of my stock reservoir, to weld in a new 1-1/4" return, then clean, repaint, all the usual fun.

I'm finding my 16 GPM, even over-spun 20%, seems to be doing fine with my line configuration. I haven't actually put a gauge on it to determine my back-pressure, but the pump RPM isn't varying at all on dry cycle, which is really a better indicator of performance than any pressure gauge. By Jags' quite-correct reasoning on flow rate being constant through the system (Kirchoff's Current Law), if my engine RPM isn't dropping, any back-pressure that is developing is of no consequence to the system operation.

 

[Isaac Carlson]

I was just talking to my wife about this and we were talking about that very thing, engine load/rpm.

How are you over-spinning by 20%?

 

[Isaac Carlson]

The hydraulic basics post above is exactly what I am trying to say. Maybe I will try a different way...
Flow rate from a positive displacement pump stays constant (that’s the GPM rating of the pump). Flow velocity can change due to restriction/friction, etc. Increased velocity increases heat and pressure but NOT flow (fluid is not compressible). If a gallon of oil is pumped out of the output of the pump, a gallon will come out at the other end (what goes in, must come out). Even if PSI and HEAT increase - you will not change the rate of flow (or the GPM) of the system. Manage the heat and pressure and everything else just works.

A well pump using a centrifugal pump and compressed air head is a different discussion.

I was referencing pressure loss due to friction/restriction, not centrifugal pumps.

The flow through the hose is the same, but the pressure drops as you move away from the source.

 

[Isaac Carlson]

When I mentioned speed increase with bigger lines and fittings, pump rpm and engine/motor load is part of that I was getting at. It won't be a lot in most cases, but a couple hundred rpm or less internal leakage adds up over time.

 

[Ashful]

How are you over-spinning by 20%?

If I recall correctly, my pump is rated 16 GPM at 3000 RPM, but my engine is set to govern at 3600 RPM.

 

[DonTee]

One of the biggest problems with the speed of my splitter is me. I don’t spin the engine to it’s rated RPMs. I’m using a Honda GX240, which is rated up to 3600 RPM. I’m using it at about half throttle most of the time.
I’m pretty cheap on gas, so I’ll bump the throttle up until it will split just fast enough.

The original engine that went with my hydraulic setup was a Briggs 23(C I think). It’s rated to 3200 RPM.

Now also I’m using a pulley and belt setup to run the pump. I’m sure I could change the pulley sizes to get more pump RPM at a lower engine RPM. Up until a certain point when the engine can no longer drive it of course.

When I get a new pump eventually I’ll have to play around with how I want to mount it. If I want to keep the belt setup, or switch to a direct drive. I know a direct drive with a coupler in between is probably more efficient.
I also know I’ll have to figure that out some time before I buy the pump, since I have to know what direction I want to spin the pump.

 

[Ashful]

A belt-driven rig is nice, as long as it's sufficient to not slip, as you can optimize the flow rate to the available horsepower of the engine, by varying pump RPM. Mine is direct drive, as it's built onto a Speeco "Huskee" chassis. It's reliable and simple, but you have to be more careful with your choice of engine, to get the desired RPM and horsepower. In my case, the engine is vastly oversized, as I couldn't find the minimum displacement I really required, with the features and configuration I was seeking.

If anyone reading this is ever buying a new engine for a splitter, don't discount the utility of electric start. Pulling over a direct-drive 16 GPM pump in January cold is no small task, without electric start. Rather than rigging a battery onto the splitter, I just put a 50A DC plug (commonly called "forklift battery plug") on my splitter, and a mate on my tractor. Bought a pair of 16-foot jumper cables, as the cheapest way to obtain AWG-6 wire, cut the clamps off and installed the mating 50A plugs, to run between the tractor and splitter when doing a cold start.

After the initial cold start and things are warmed up, I just use the pull cord for re-starts, for the rest of the day.

 

[Isaac Carlson]

DonTee- most splitter pumps are designed to be direct drive, so that would most likely be what you end up with when replacing the pump and they can only function in one direction because of the 2 stage check ball.

 

[DonTee]

When I was looking at pumps before I swore I saw some versions that spun CW and others that were CCW. But now that I look again, I only see CW pumps. Which would make sense for direct mounting it to my CCW spinning Honda engine.
And the one I posted earlier from Vevor is CW as well. So yeah I’d have to direct mount it.

The splitter that my engine came off of had the pump mounted like that.

If I wanted to stay belt drive I’d have to mount the pump off the side of the splitter. So it was still spinning the correct direction.

 

[DonTee]

For funsies I looked up the specs for my current hoses. They’re Aeroquip 2651-6 hose. Size is .31” ID

 

[Isaac Carlson]

For funsies I looked up the specs for my current hoses. They’re Aeroquip 2651-6 hose. Size is .31” ID

And the fittings are much smaller, maybe half of that.

Pumps are not designed for a side load on the shaft. They don't have bearings. You would have to get one specifically designed for belt drive. I have one for my truck and it weighs a ton, but I think it is 30 gpm, so that adds weight.

 

[DonTee]

I didn’t think about the bearing thing. But I bet you’re right. That cheap pump is most likely not designed for a side load like a belt drive would put on it.