Full-size electric wood splitter

[beenthere]

I like that idea. /forums/images/graemlins/smile.gif

 

[newlife]

I can't believe that here is so much interest in an electric splitter, I thought I was the only werido out here. I built an electric wood splitter about 15 years ago, for the same reasons you are considering it now, no maintenance. I only use it about 3 hrs/yr and I can't remember the last time it needed anything. I has a 7HP electric motor and a 2 stage pump. It cycles in high speed in about 5 seconds. It requires a 30 amp 240 volt line.

 

[rockinmywaypa]

no sarcasm intended I just got carried away thinking about the possibilities.

 

[rockinmywaypa]

The ironworker I was talking about isn't a person, it's a type of hydraulic press that can shear off steel angle, flats or round rods. It can punch holes and form shapes according to attachments used. [/url] web page This is my first attempt at adding an url so I hope I get it right.

 

[EdK]

</font><font color="blue" class="small">( no sarcasm intended I just got carried away thinking about the possibilities. )</font>

Then in that case I'll admit I've thought of building either a stand-alone power unit as you described or one to be driven from my PTO shaft - complete with quick connects! /forums/images/graemlins/blush.gif

 

[bczoom]

Oops. Shows you how much I work with steel. I could probably build a garage sized building faster than I could weld 2 pieces of steel together. But I don't bother welding... the guy down the road "was" (he's gotten out of the business) one of the top welders in the country.

 

[RonL]

Ed

I have a 20 foot shipping container on my property that I am using for storage right now. My intent was to use the shipping container as a mechanical building once I built a barn/workshop. This Spring I want to pour footings for the container, put on a sloped roof that extends out to the sides, and run a 100 amp subpanel to it. I want to put my compressor and the hydraulic pump here. One side of the container will have all the electrical and air connections that I need. The other side will be where the splitter will go. My design for the splitter calls for the beam to be cantilevered out to the splitting wedge. The wedge is at the end of the beam. The control lever will be in the middle above so that I can split from either side. I figure that I could put my loader bucket under the wedge and the split wood would fall into the bucket. I'm thinking now that I could put in a drop off at the end of the splitter. That way I could put a bin under the end to catch the falling wood. Pick up the bin with my forks and run it into the woodshed. I figure that I'll be doing all of my cutting to length and splitting in one spot. And I like the idea of just throwing a switch and not having to maintain another gasoline engine.
As others have said, you could build a hydraulic power supply and put on quick connects. Running hydraulics would be as simple as plugging in. If you didn't want to fabricate a splitter you could buy one of the three point splitters and attach it to your pump.

RonL

 

[EdK]

Sounds like a good "system" you will have for handling your wood. As you know with wood it's all in minimizing the handling.

I have not as yet refined the felling through splitting portion of the process. I am putting together a winch for the rear of my tractor to help with that. I find forks fantastic for handling logs and stacks of 4-5 footers.

What I have thought out well is the handling after the wood is split. I have my 11&13 year old kids stack the split wood on pallets. The pallet is situated at the base of the splitter in a simple wooden u-shaped fixture with 5' high sides. When the kids have one finished I use steel banding to secure the stack to the pallet. Then I use the tractor to move the wood from there on to the drying location. Once dry, I move the stack into my walk-out basement through a pair of doors. I can reach into the basement and place the pallet on a dolly with casters. From there it is a cinch to roll over about 40' to the wood boiler, cut the straps and let rip.

With the help of a little child labor I don't have to even touch the wood coming off the splitter until I'm loading the firebox! A downside is the steel strapping costs which runs about $2/stack - not too bad.

 

[RonL]

Now I have a question for those familiar with hydraulics. The Barnes 2 stage pumps are rated to run from 500 to 4000 RPM. Their rated output is at 3600 RPM. Other than cost, is there a difference in running a 11 GPM pump at 3600 RPM and running a 22 GPM pump at 1800 RPM? Is there a loss of efficiency? Would the pump last longer?

RonL

 

[fractal]

Several log splitter manufacturers will sell you an electric version as well as a gas version. I believe I remember reading that a 3hp electric is equivalent to a 5hp gas motor splitter. I have also read a few web sites by people who have taken a gas powered splitter and converted it to electric.

http://www.westpowertools.com/bachtold/ lists a 12 ton electric that uses a 1 hp, 120v electric motor that is comparable to a 3.5 hp gas motor.

The full size models I have seen use 3-5 hp electric motors that are specified to plug in to electric dryer plugs or welder plugs.

Does your genset have a 30-50 amp 220 outlet? If so, you will need 50-100' of 6-8 awg wire to run an electric log splitter. They also tend to cost considerably more than a gas powered splitter.

 

[jim_wilson]

My father has had an electric powered Super Split wood splitter for probably over 20 years now and it works great. I don't recall what HP the motor is but it will run on a good 20amp 110V circuit. It is the fastest wood splitter I have seen and it is quiet and easy to use. You can split any piece of wood you can lift up to the bed. Check out the website at: Super Split log splitters

 

[EdK]

</font><font color="blue" class="small">( Does your genset have a 30-50 amp 220 outlet? If so, you will need 50-100' of 6-8 awg wire to run an electric log splitter. They also tend to cost considerably more than a gas powered splitter. )</font>

Yes, I've got plenty of 220V current to run the splitter. I can't think of any reason why an electric splitter should cost "considerably more" than its' gas counterpart except for supply and demand. Of course this is the build it yourself forum /forums/images/graemlins/smile.gif

 

[BigEddy]

I downloaded this file some time ago - details the whole process. I was intrigued - but haven't got to doing it yet. Still using the maul.
www.green-trust.org/LogSplitter.pdf

 

[fractal]

Probably supply and demand. A quick search of the northern tool catalog shows a 5hp gas motor can be had for 210 and a 3hp electric for 90. The gas motor turns at 3600 rpm and the electric at 3450. The cord and GFI can not be that expensive, so I too am curious why all the electric models are so expensive.

I myself have been looking for a used box-store splitter that the former owner has neglected to the point that it does not work any more. I too would either convert to electric or run off tractor hydraulics. Electric would be convenient enough for me since my wood pile is fairly close to the house.

 

[BigEddy]

Now there's an idea - electric when at home, and tractor hydraulics when away! A little bit of plumbing and a selecter valve, and we're all set

 

[RonL]

Ed

Since this thread started I've been reviewing my engine, motor, and hydraulic theory. I'm planning for a fire protection water pump connected to a cistern. Hydraulic theory is the same for water or oil. A small gasoline engine will put out up to its rated horsepower. It has very little torque rise. If a gasoline engine is loaded beyond its rated horsepower it will bog down and stall. If an electric motor is overloaded it will continue to put out an increasing amount of horsepower until it reaches its locked rotor torque. This is how Sears can claim its compressors can "develope" 6.5 HP. However, overloading an electric motor for a length of time angers the god of electric motors and he manifests himself in the form of smoke. A continuous duty 5HP motor with a service factor of 1.0 will produce a constant 5HP without overheating. A 5HP motor with a service factor of 1.15 will produce a continuous 5.75 HP without overheating. I located a single phase 5HP 3450 RPM C face motor with a service factor of 1.15. With the barnes 11 GPM two stage pump I can run it up to 2750 PSI without going into the "red". If used with a 3000 PSI 4x24 cylinder with a 2" rod it will yield the following: at 2750 PSI it will yield 34,500 pounds of force. At high flow the cylinder will take 7.4 seconds to cycle forward and 6 seconds to return. At high pressure the cylinder will take 27 seconds to cycle forward. Assuming that the return stroke will always be at high volume the full cycle will take anywhere from 13.4 seconds to 33 seconds, depending on what point the pump kicks in to high pressure. The pumps are factory set at 650 PSI to kick into the high pressure mode. On a 4 inch cylinder 650 PSI yields 8,164 pounds of force.

I noticed that Barnes has a pump, motor, and tank combo that uses the 16 GPM pump with a 5 HP motor. When I checked the specs I found that the motor was a 3 phase very high service factor motor and the pump was set to kick into high pressure mode at 450 PSI. The pumps are adjustable to kick into high pressure mode at from 400 to 800 PSI. 16 GPM at 450 PSI equated to 5 HP. I think you could use a 16 GPM with a 5 HP single phase motor if you set the cross over point at 450 PSI. At 2000 PSI you would be crossing over into the "red'. 2000 PSI in a 4.5 inch cylinder yields 31,800 pounds of force. 450 PSI in a 4.5 inch cylinder yields 7155 pounds of force. In another thread another poster stated that he put a pressure gauge on his 4 inch cylinder wood splitter and didn't more than a 1200 PSI reading. Someone else stated that they didn't get more than a 1500 PSI reading on their 5 inch cylinder. I think the dynamics of wood splitting a such that the pump is well within its limits 99.9% of the time. Occasionally a tough piece of wood is encountered. I think a 16 GPM pump with the cross over point set to 450 PSI would work with a 5 HP motor. The motor would not go into the "red" unless you were pumping at over 2000 PSI. I think a good quality motor would not be "phased" ( pun ) by an occasional 'blip" into the "red". Because these pumps are positive displacement, the valves used for wood splitters are open center. The ones sold by Northern for wood splitters are factory set at 2250 PSI relief. They are adjustable up to2750 PSI. They are spring centered so that you have to physically hold them on the splitting stroke. They automatically return to center when you let them go. If you stand there holding the valve while the pump is overloading for a length of time, you may anger the god of electric motors. You can set the pressure up high and use the valve to control overloading manually. If you are going to lend the splitter to someone that you have no faith in you can always turn the relief pressure down to 2000 PSI.

I compiled the following figures for a 4.5 x 30 x2 cylinder using both an 11 GPM pump and a 16 GPM pump. 11 GPM: high volume out stroke 11.7 seconds, return stoke 9.4 seconds, high pressure stroke 42.8 seconds. 16GPM: high volume out stroke 8.0 seconds, return stroke 6.5 seconds, high pressure stroke 32.2 seconds. 11 GPM pump: between 21.1 seconds and 52.3 seconds for a full cycle. 16 GPM pump: between 14.5 seconds and 38.7 seconds for a full cycle.

Incidentally, it appears that Grainger no longer carries the C face adapters for hydraulic pumps. Vescor has a full line of adapters.

Sorry for the long post. I had all these numbers rattling around in my head and had to let them out.

RonL

 

[EdK]

Fantastic post Ron!

I'm with you on the idea of (carefully) stretching the 5hp motor for the 16gpm pump.

My hat's off to you for all of the homework you've done on this. By the way, how do you come to possess this degree of knowledge of hydraulics and motors? Is it part of your formal training or are you self-taught? My background is electronics so I get the motor stuff but I know nothing about hydraulics and need to bone up on the subject for projects like this.

Were the Barnes combos you described some sort of self-contained hydraulic power unit or an engineered parts recommendation/kit?

Thanks again - Ed

 

[RonL]

Ed

The Barnes units were prefabbed factory units.

With a little effort you can find almost anything on the web. The information is out there.

I think I get my engineering streak from my father. He was a self taught engineer who had over 40 patents in his name. He always encouraged me when I would build "projects".

RonL

 

[EdK]

I realize that this post complicates the splitter design but I offer it in the continuation of RonL's spirit of trying to stretch the proposed electric 5hp motor as far as possible. It does seem that for a single phase motor, 5hp is a nice common size that doesn't cost too much and will work with a reasonable amount of 220V current - that which can be had from a 30A dryer receptacle or produced by a typical genset. So sticking with it as a benchmark size we observe via RonL's calculations that we end up with a modest and capable design.

Why not model the splitter after the Split-Fire type two way splitter designs to either (1) double the speed of splitting or (2) perhaps even better split the difference (pun intended /forums/images/graemlins/grin.gif) and perhaps bump up to a slightly larger cylinder resulting in more power an and decent cycle time given the two-way design?

I see that there are TBN members using this type of splitter. What would be helpful is a few close-up shots of the two-way mechanism. The images on the manufacturer's web site are not very detailed (probably for a reason /forums/images/graemlins/grin.gif).

 

[rambler]

Just remember a hyd cylinder has more pressure extending than retracting - you need to subtract the diameter of the rod on the retraction lbs/sq in.

Some wood splitters have a special thicker rod so the return stroke is faster - as well as being stronger. These splitters especially would not work well converting to bi-directional splitting.

--->Paul