log splitter plans

[LD1]

One book that I had ( I cant find it now) actually listed that formula for the sizing of an ELECTRIC motor. And not just HP requirements. Those #'s that you listed do seem a bit small to me. An example of where I work, we have a denison 29GPM pump and it is driven by a 15HP 3phase motor. And we have several of them units where I work and they are all sized the same.

As an other example, when we hooked our 11gpm pump up to an electric motor, the current draw was 19-21 AMPS @ 3000psi. Current draw is the most important factor to look at.

As for the link to your "motor of choice", is not a good motor at all. First it is an Air comp motor, which are built much lighter, usually not designed for contunious duty, only have a SF of 1.0, and it is an open motor and not a TEFC. That motor is also rated @ ~20 amps, which would barley be adequite on the 11gpm pump, based on the current draw that we have tested. If you go to TSC and compare their "farm duty" motors to the Air comp motors, you'll see what I mean. The Farm duty is twice the size and usually a "true" 5HP motor is rated between 25 and 30 amps.

This is close to what you need, although I still wouldn't use it on bigger than a 16gpm and I would also try to find a TEFC motor, otherwise the benifit of electric motors lasting a long time goes right out the window.
Leeson Reversible Electric Motor — 5 HP, 3450 RPM, Model# 131616 | Electric Motors | Northern Tool + Equipment

 

[J_J]

I had a chance to buy a 5 HP 240 v SF1 to day. made by Emerson for $50. I still might buy it. There is something that some of you are not thinking about, and that is, probably only 80% of log splitting is done in the high pressure mode. So in essence, the 5 HP motor would work even with a service factor of 1. Where the motor comes up short would be if the log splitter had to run high pressure all the time. In splitting easy to split wood, the engine and pump is not working hard most of the time. So he could hook all this up and it might work fine for him. You and I know that a good industrial/farm type motor would give better service, but if that is all he has, then so be it. He might have a log splitter, but it may not be up to some standards.

 

[gould37]

I have been searching for a motor for my project. Running to the local electric shops. JJ that sounds like a great deal on a 5hp electric. I was more interested in experimenting with this set up as opposed to a gas engine. The motor from nothern that was posted, looked like it would work until I noticed that there is no way to attach the pump to the face of the motor. A pulley set up is out, because the pump can not take any lateral force. I am going to keep working on this one and will keep you all posted.

 

[LD1]

I have been searching for a motor for my project. Running to the local electric shops. JJ that sounds like a great deal on a 5hp electric. I was more interested in experimenting with this set up as opposed to a gas engine. The motor from nothern that was posted, looked like it would work until I noticed that there is no way to attach the pump to the face of the motor. A pulley set up is out, because the pump can not take any lateral force. I am going to keep working on this one and will keep you all posted.

Are you talking about the air compressor motor that bassgrinder posted ot the one that I posted. If you are talking about the one I posted, that was just for an example, but you do want to get one that is a TEFC.

As far as attaching it, it does not have to be a c-face motor. the base mount will work just fab up a vertical L-shaped mounting plate and bolt it to the motor, and then to the plate where your gas motor bolts. Heres a diagram

 

[J_J]

I have been searching for a motor for my project. Running to the local electric shops. JJ that sounds like a great deal on a 5hp electric. I was more interested in experimenting with this set up as opposed to a gas engine. The motor from nothern that was posted, looked like it would work until I noticed that there is no way to attach the pump to the face of the motor. A pulley set up is out, because the pump can not take any lateral force. I am going to keep working on this one and will keep you all posted.

Sorry, but did not look at the motor face. However, you can connect it shaft to shaft using Love Joy units. Just build a stand for the pump and align the electric motor shaft to the pump shaft, and it should work.

 

[T.C.]

I have a question on this subject you guys should be able to answer. I currently have a pull behind splitter that hooks up to a 2" ball that is set up to run off tractor hydrolics. It was given to me and I do not have a tractor to power it. I would like to mount a pump, tank and motor on this so I no longer need a tractor.

I currently have a 10 hp gas motor that I can use to power the pump. I would like to get a 16GPM pump(affordable). Through out this forum there are different recommendations on what size motor to use with different pumps and they all say to use a 5-8hp for 16GPM.

My question is, can I use the 10hp motor on the 16GPM pump with out it damaging it or anything like that? Also what is the minimum tank size I can use?

 

[J_J]

More power is always good. The pump will put out about 2500 psi in the slow mode and about 650 psi in the high speed mode, which is what you will be running most of the time.

The new thoughts on tank size is one gal tank for each gal pumped. You will need a pump mount , some Love Joy connectors, and you should check the relief settings on the splitter valve.

In the high pressure mode, you are pumping 4 GPM at 2500 psi, and 16 GPM in the fast mode/low pressure mode.

Engine to pump adapter.

https://www.surpluscenter.com/item.asp?UID=2009091118020666&item=1-1581-A&catname=hydraulic

 

[T.C.]

Thanks JJ. Appreciate the recommendations on the parts also, wasn't really sure what I needed.

 

[ka81504]

so gould37 did you ever build one and how did it turn out?

 

[ByronMill]

One book that I had ( I cant find it now) actually listed that formula for the sizing of an ELECTRIC motor. And not just HP requirements. Those #'s that you listed do seem a bit small to me. An example of where I work, we have a denison 29GPM pump and it is driven by a 15HP 3phase motor. And we have several of them units where I work and they are all sized the same.

As an other example, when we hooked our 11gpm pump up to an electric motor, the current draw was 19-21 AMPS @ 3000psi. Current draw is the most important factor to look at.

As for the link to your "motor of choice", is not a good motor at all. First it is an Air comp motor, which are built much lighter, usually not designed for contunious duty, only have a SF of 1.0, and it is an open motor and not a TEFC. That motor is also rated @ ~20 amps, which would barley be adequite on the 11gpm pump, based on the current draw that we have tested. If you go to TSC and compare their "farm duty" motors to the Air comp motors, you'll see what I mean. The Farm duty is twice the size and usually a "true" 5HP motor is rated between 25 and 30 amps.

This is close to what you need, although I still wouldn't use it on bigger than a 16gpm and I would also try to find a TEFC motor, otherwise the benifit of electric motors lasting a long time goes right out the window.
Leeson Reversible Electric Motor 5 HP, 3450 RPM, Model# 131616 | Electric Motors | Northern Tool + Equipment

Maybe this will help clear up a little of the confusion of the "equivalency ratios" from combustion engines to electric motors that are out there. Most standard electric motors can handle short duration instantaneous overloads of 200 to 250%, regardless of service factor. This means they are capable of producing roughly twice the rated horsepower, but will be drawing twice the full load amps. A combustion engine is rated at maximum HP at a specific RPM and cannot produce over that value, even for an instant. Exception to that would be an engine that is equipped with a large mass flywheel to provide for short duration instantaneous overloads. Not typical in any existing small engine designs, so not really a point of discussion.

In an application such as a logsplitter, in particular with a 2 stage pump where there tends to be short duration high load conditions (the initial split phase), an electric motor would be be able to provide for the high torque demands where a combustion engine of the same HP rating would not be able to. This would not hold true if the hydraulic system ran constantly or very repeatedly at the higher load demands. The electric motor overload protection would kick out or the motor would fail over time due to overheating.

This is why you see general statements out there that compare electric to combustion at a 2 or 2.5 to 1 ratio. Strictly based on ability to overcome instantaneous overloads. A combustion engine has to be sized to overcome the maximum load condition encountered. If a system design calls for a full time (constant) HP value with no instantaneous overloads expected, it does not make any difference if the power source is an electric motor or a combustion engine, HP needed will be the same.

Air compressor motors are not really "made lighter", they are just rated by their instantaneous overload or startup torque. Air compressors are usually limited by the ability of the motor to overcome the high startup demands. So basically they are overstating the HP by a factor of about 2. You can tell this by the lower nameplate amp ratings.

1 HP is approximately 750 Watts, regardless of voltage. Voltage times Amps equals Watts. 120 V motor pulling 20 amps is 2400 watts, or 3.2 HP. 240 V motor pulling 10 amps is the same 2400 watts and the same 3.2 HP. But if either of those motors were instantaneously overloaded and drew double the amps they would be providing 6.4 HP. Of course if that continued for any amount of time overloads would kick out. I think you get the idea.

The values and calculations provide are general and somewhat over-simplified but are the basis for how electric motors work. Values will vary some depending on motor design and some other variables.