Rebuilding a log splitter

[R T]

I know that I'm not the only one on this site who has rebuilt a log splitter, but with over 800 threads it's difficult to read through them all.

So here goes....
Two years ago, I purchased a monster of a home built log splitter. I mean, this thing is a beast. It has a ram that is 7" in diameter (it was probably scavenged from a Caterpillar earth mover). This splitter comes with an 8hp motor, which I cannot get to run. So, in my usual fashion, I'm going to replace the motor and the ram with something BIGGER!!!!

My plan is as follows:
- replace the existing ram with a 5" bore, 24" stroke ram (I've already bought it)
- replace the existing horizontal shaft, 8hp motor with a 17.5hp, vertical shaft motor (I've already bought it)
- replace the existing 2 stage pump with a 28 gpm pump
- replace the existing tank with a bigger tank
- replace the existing control valves with new valves (the old ones are leaking)

My questions are:
1. Can I use a 20 gallon pneumatic tank for the reservoir?
2. Do I need a 28 gpm pump or can I get a way with something smaller?

I should also mention that this splitter comes with a lift wing to help load the heavy logs so will that potentially add to the load required for the pump? Also, because the motor came from a lawn tractor, I will need to add a solenoid and battery in order to start it.

 

[muddstopper]

With the 5in bore cyl, I would go with the 28gpm 2stage pump. I would check the ports in the cyl to make sure that it doesnt have small holes inside the fitting. If its a china cyl, they are bad to weld on a 3/4 port with a 3/8 size hole inside. The 20gal tank will work, once you weld in the appropriate size ports. I suggest a suction filter as well as a return filter. As for the valve, most of your splitter valve with detent are only rated for 25gpm flow. Dont let that stop you from using one. You can always add a dup valve later for oil return on cyl retraction. I use a 25hp kholer eng, 28gpm pump and a control valve rated for just 25gpm. I dont have a dumpvalve on my spiitter and my hyd tank only holds about 10gal of oil. I found I seldom run my engine at wot so I am not pumping the full 28gpm of oil the pump is capable of. I do have my oil heat up, but I usually give out before the oil gets to hot. The 5in cyl seldom makes full tonnage so the oil isnt under full pressure all the time. JMO

 

[cantoo]

Sounds like you might as well buy some surplus steel and build what you want instead of fighting with the steel that you have left.

 

[WoodTick007]

Regarding the 20 gallon oil tank. If you're running a 28 gallon per minute pump and have a 20 gallon hydraulic tank. Just do the math... LOL. Most of the store-bought log splitters come with 5 gallon tanks and boast 16 gallon per minute pumps. The big response on the arboristsite is... Well, they work. When I would like to solve in my system is the reducing the moisture or eliminating the moisture due to the heating and cooling cycle of the oil. I guess I could put a recirculating pump on the system and a electric tank heater to keep it above the dew point. But over the period of 30 or 40 Years of running that electric heater and pump I could probably cover the cost of the replacement oil I haven't done the math lol

 

[ChoppyChoppy]

20 gal tank should be ok. More oil isn't a bad thing though at $50 a pail for oil, even 20 gal is $200 of oil.

I have only a 30 gal tank on my processor with about 45gpm worth of pumps. I do have an oil cooler though, but I have it setup on a thermostat so it only cools if the oil is over 145*.

 

[ChoppyChoppy]

Regarding the 20 gallon oil tank. If you're running a 28 gallon per minute pump and have a 20 gallon hydraulic tank. Just do the math... LOL. Most of the store-bought log splitters come with 5 gallon tanks and boast 16 gallon per minute pumps. The big response on the arboristsite is... Well, they work. When I would like to solve in my system is the reducing the moisture or eliminating the moisture due to the heating and cooling cycle of the oil. I guess I could put a recirculating pump on the system and a electric tank heater to keep it above the dew point. But over the period of 30 or 40 Years of running that electric heater and pump I could probably cover the cost of the replacement oil I haven't done the math lol

I have a 1000watt heater on my oil tank. I usually plug it in for 3-4hrs before I fire it up when it gets around zero or below. Helps with getting the machine going in the morning.

1000 watts for 4 hours a day for a month is about $22 a month at our power rates. Plugged in 24/7 would be about $135/month (ouch!)... heck my power bill at home averages about $50/month!

 

[FlyingDutchman]

I was recently looking at this myself on my build. One of the most important deals is de-aeration. you need enough fluid to allow bubbles to rise to the top of the tank. Diffusers on return and strainers on pickup help reduce turbulence of the oil to allow any sort of air to escape the oil as to not be taken back up into the pump pickup. In less than ideal conditions, eventually the oil will foam and the hydraulic functions will have no power because air compresses much better than oil. If your system has really fast cycle times and high oil velocity, the need for a larger tank and return/pickup is more critical. My old setup had a 4 gallon tank and a 10gpm single stage pump and they never had problems with it. But cycle times are super slow (20 sec on 30" stoke). The splitters with the sub 10 sec cycle times seem to be the ones with the bigger tanks.

 

[ChoppyChoppy]

Once it's bled, shouldn't have any air in the system though.

 

[FlyingDutchman]

Theoretically yes, but high flow and pressure differential going into the tank creates turbulence and potentially, velocity cavitation at the back of sharp edges between the incoming pressure and the tank (similar to a boat propeller) that will amplify as it gets sucked into the pump inlet. The higher the reservoir turbulence the more you have propensity for foaming. Once it starts it doesn't take long for it to go crazy if it starts going through the pump. The diffusers/inlet screens and properly sized lines lower turbulence and reduce the required fluid volume to allow air to rise to the surface.

Your post in my thread about line sizing is what got me on it, so thank you

 

[R T]

Thanks everyone for your replies.

So, it's looking like a 30 gallon tank is a MUST! No messing around with that.

Also, a 28 gpm pump is also a MUST. I suspect that anything smaller will be just a big disappointment. On that note, any preferences as to which make? I found a pump on Surplus Centre's website (http://www.surpluscenter.com/Hydrau...-Pumps/28-GPM-Dynamic-2-Stage-Pump-9-7971.axd) for $231 USD. When comparing it to the cost of other pumps, that's a great price. However, is it cheap because it's cheap?? You know: you get what you pay for.

 

[R T]

Sounds like you might as well buy some surplus steel and build what you want instead of fighting with the steel that you have left.

That's exactly what this splitter is. It's 1/2" steel that would split anything. Well, almost anything. The guy before me blew it up so I'm rebuilding it. It has potential so that's what I'm working on.

 

[nvr-enuf]

RT - Are you still working on your splitter project?
One suggestion is to run a cooler - will reduce the air in your oil, keep your temps low and add capacity. I run a 15 gallon hyd tank w/ dual (tandem) 17 GPM pumps and a 25HP gas engine. No issues.
I have a low cost cooler for sale - check classifieds
Also if you haven't already bought your pump, I would suggest looking for tandem gear pumps. They are cheap and reliable - check ebay. Per Haldex when my two stage pump was junk after 5 years of use - he stated that was "good life" for a two stage pump. Inside, there is a ball that pounds on a seat for switching as well as other moving parts. When I looked into a 2 stage, I didn't want to replace after 5 years.
By running a tandem pump, you can have a high pressure / high force (1 pump) as well as a high speed / low force (2 pumps)
Essentially you control when you want to activate the low speed vs having the pump decide

 

[R T]

Hey nvr-enuf,
Yes, I'm still working on my project splitter. I'm slowly assembling the needed pieces so that, when the weather warms up (currently -2 deg. C here), I can start assembling it.

I bought a new, 28 gpm pump from Bailey Hydraulics (http://www.baileyhydraulics.com) and will get that installed once the weather cooperates.

I will be running this splitter mainly during the summer months so it will naturally be running hot, if not very hot. Since this is my first attempt at building a splitter, I don't know what to expect.

Since I initally acquired it, I have bought the following replacement parts:
- 28 gpm 2-stage pump, new
- 5" ram, new
- valves, new
- pump mount, new
- 15HP, vertical shaft B & S, used
- metal to build a new reservoir

I know that I have some welding to do as well as purchasing hoses, fittings and a battery so I'm really just getting started. I'm *hoping* to have this running by the time that I start to split firewood (potentially August 2018). Fingers crossed!

I haven't figured on needing a cooler but will definitely check into this, thank you very much!

 

[nvr-enuf]

Sounds like you have a good start on components. The cooler I have available has a bracket to hold the hydraulic filter along with the filter housing. Coolers are the most missed components in a splitter, everyone relies on the hydraulic tank to dissipate the heat into the hyd oil. Having a cooler also increases your oil capacity - rule of thumb is 3 to 1 when not using a cooler. 3 gallons of cooler for every GPM of your pump output. If you build a pusher style splitter - I would suggest a slip on wedge at the end so you can raise and lower as you desire. I have a 6 way and could not live with out it. Thinking about adding 2 more knives for an 8 WAY! Good Luck, have fun with the build

 

[R T]

Hey nvr-enuf,
I haven't forgotten about the cooler; I've been busy with, well. many other things that seem to come along, and the weather isn't helping (-5 degrees F. this morning).

So, if I understand correctly, a configuration such a mine with a 28gpm pump and a cooler would require approximately 80 gallons of hydraulic fluid? Wow! I might need to call in an oil tanker to fill my splitter.

Seriously though, as soon as the weather starts to warm up, I will start to work on it. I need to remove the old cylinder (it's no longer usable), the valves, the hoses, and the engine. Essentially, I will be starting from square one. and start rebuilding.

Will be in touch!

Cheers,
r.

 

[GVS]

Sounds like you have a good start on components. The cooler I have available has a bracket to hold the hydraulic filter along with the filter housing. Coolers are the most missed components in a splitter, everyone relies on the hydraulic tank to dissipate the heat into the hyd oil. Having a cooler also increases your oil capacity - rule of thumb is 3 to 1 when not using a cooler. 3 gallons of cooler for every GPM of your pump output. If you build a pusher style splitter - I would suggest a slip on wedge at the end so you can raise and lower as you desire. I have a 6 way and could not live with out it. Thinking about adding 2 more knives for an 8 WAY! Good Luck, have fun with the build

I have a 16 GPM pump on "35"ton Husky from TSC.Using your numbers I'd need 48 gallons of hyd.fluid.This splitter has a 5 gal tank and an all up capacity of about 7 gal. No cooler and I've never seen my fluid temp go over 150*F on a hot day after 3 hours of steady working.This is not a high temp. for hyd. fluid.This isn't even high if you were using water for hyd fluid.

 

[nvr-enuf]

The 3 to 1 rule of thumb is based on running a hydraulic motor when you have system pressure & high pump flow at 100% duty cycle. Splitter's are different being that of not having a 100% duty cycle both on the pressure and flow. Some people tend to lower the RPMs while they are staging / getting ready to split wood which helps reduced the heat. The Husky splitter is not "working" at 16 GPM, it is only flowing 16 GPM at 650 psi. At 650 psi, you are not making heat (using HP). The Husky is make HP / Heat on the second stage which is roughly 3.5 GPM. The Husky 35 Ton vertical / horizontal splitter has a 6.5 gallon tank. A 5" cylinder with 24" stroke is 2 gallons just to fill the cylinder, that means fully extended you would only have 3 to 4 gallons in your hyd tank. If you talk to the owner of SplitEz / Bad Dawg splitters (very cool splitters), he will state over and over the number oversight on building a splitter is taking into account aeration & hyd heat. I am not doubting the Husky splitter is fine with ah 6.5 gallon hyd tank. I am not a fan of 2 stage pumps, especially when Haldex told me to expect 4 to 5 years life out of one. I run 25HP / 34 GPM and I only have a 15 gallon reservoir. My cooler has a thermostatic switch (125F ?) to kick in the fan. When I work my splitter, the fan kicks in. By keeping my fluid around 125F, I have noticed my cycle times stay consistent, my machine does not slow down with hot oil. For roughly $100 bucks, a cooler is very helpful for someone that is trying to run high GPM and high pressure for a splitter. Lastly what is often overlooked is the size of the hoses. I have several pressure gauges on my machine to know the pressure it takes just to move 34 GPM - turning over my fluid in my hyd tank in less than 30 seconds. By running small hose sizes, you are loosing HP that could be put into the log as well as generating heat

 

[Ted Jenkins]

OK RT most will want to know how this project turns out, Mud has pointed out some great guide lines as others have. It is judgement call on most issues. If you run hard in the summer you need cooling. On my latest splitter build I used heavy wall tubing for my hydro tank and back bone of the cradle. I have two 6'' tubes laying horizontal with a 1/2 flat bar welded on the top of the two tubes with the tubing being the tank and cooler for oil. If you have some kind of cooling you will get along fine with just 10 gallon or so for a tank. I have seen some use a auto cooler or trans cooler but you may need two or maybe three to get a good flow rate. In the summer the oil can get just uncomfortable to touch after several hour of use. A 5'' ram should work well for most situations. A multi wedge work well for some and not others it depends on the wood you get. A 17.5 HP motor is a little small for a 28 GPM pump, but pretty sure it could work just fine may need to be adjusted. You can modify the engine quite a bit to give you better performance. I made a header system with a auto muffler which helped mine breathe better. The pump mount from a lawnmower motor is a bit of a challenge. I at one point took a regular mount from a another pump and welded a plate on the motor side and carefully drilled the holes to match the motor mounts from the motor. You might need to set up a flywheel to make the motor run smooth, but after trying it it may seem not necessary. Follow the AS member guidelines and you will be chugging along. We have not so good weather too, but now is the time to get ready for warmer weather. Thanks