Electric motor questions

[lennyzx11]

I have two motors available for around 100 bucks that I’m thinking of using for a electric splitter project with an 11 gpm pump.

For those who know,
Which of these two motors would be the “better” motor all other things being equal?




This is one of those “play with it” projects.

Lenny

 

[K5lwq]

The Leeson is probably a better quality. Other than that they are equal in output.

 

[4570Man]

They’re both 3400 rpm 2 hp. I’d take the leeson with everything else being equal. But you probably need more power. An electric will handle a high toque load better than a gas motor but I think 2 hp is still undersized.

 

[texasranger556]

I agree, 2HP is going to be underwhelming compared to nearly any gas powered splitter. Driving an 11 GPM pump, your 2HP motor will stall out at a couple hundred PSI.

 

[WranglerX]

IF you are contemplating something like a 20 ton splitter you are probably going to be better served with a 240V 5 HP motor....

Dale

 

[ptsg]

For a 2 stage pump, it might work but definitely on the short side. The low volume high pressure pump is usually somewhere around 0.22 ci.

On one of various versions of my log splitter, I had it powered by 2.5HP 3 phase 400V electric motor. It had a 0.305 ci gear pump with the relief valve set at 2600 psi. It worked very well and the motor would only lose a couple hundred RPM due to the load.

 

[robstaples]

Go to the technical help at SurplusCenter.com. Surplus Center
By my calc you need a bigger motor or a smaller pump. With a two stage pump and high pressure side at 3.2 gpm, you would only get 1000 psi before it stalled. A bigger cylinder would work but slower splitting.

 

[lennyzx11]

I’ve been told that 2 hp will be too low.

I have a dr electric splitter that is 1300 watts at 110 volts. That works out to 1.75 hp roughly. It works okay but yes is slower. But not unbearably so.

With a 2 stage pump, my theory is that the splitter will work. The unloaded speed is 11 gpm. The second stage is 3.6 gpm.

I don’t have enough knowledge yet to figure out on paper what the theoretical electric motor/hydraulic pump equivalent combination is to equal a typical 5hp 20/22 ton splitter but am working through it slowly.

One of the wishes was to be able to run one on a typical 30 amp dryer connection. That’s why the motor size decision.

 

[workinonit]

Build it and try it. Worse case scenario it doesn't work and you have to scrounge up a larger motor. At least you would have everything else ready.

 

[workinonit]

Build it and try it. Worse case scenario it doesn't work and you have to scrounge up a larger motor. At least you would have everything else ready. Based on the nameplate if you double the size to 4 HP you could still run it on the 30 amp circuit.

 

[Sawyer Rob]

The Leeson will have slightly more power too...

SR

 

[ZJ_HR]

I made log splitter with electric motor drive.

As I'm from other side of the pond (as will my friend @Sawyer Rob tell), I'm not so familiar with your measuring system, so I'll explain it in SI (metric units) and try to convert in US units.
My splitter is driven by 3ph electric motor (3x400V, 50Hz) w. nominal power 5,5kW continuous, about 1400rpm.
Pump is 19 ccm/rev, over pressure valve set @200bar. So, about 27 lit/min flow.
At full pressure motor is loaded with 9,5kW (intermitent @200bar peak Pressure).
Hydraulic cylinder is 80/56mm dia (piston/rod), and at 200 bar splitting force is limited to 10ton.


Let put units in US:
Hyd. cylinder is 3,15/2,2in dia.
Motor 7,5HP (continuous).
Pump 1,159 cuin/rev, at 1420rpm give 7,1gpm
Pressure (max): 2900psi
With mentioned pump at 2900psi motor is loaded with ~13hp (motor is shortly overloaded 73% more then nominal power).

Now you can rough calcualate ratio:
your motor is 2hp, and as is 1ph, I doubt that you can overload it more then 50%, say 3HP max.
So 3/13*7,1...You can pull out 1,6gpm@2900psi max.

For that 1,6gpm@3450rpm, you have to buy pump with 0,11cuin/rev.
Honestly, this splitter will be very slooow (if you need force) or weak (if you want speed).

For example, if you find cylinder like I have (3,15in dia), it will move 0,8in/sec.

 

[4570Man]

I made log splitter with electric motor drive.

As I'm from other side of the pond (as will my friend @Sawyer Rob tell), I'm not so familiar with your measuring system, so I'll explain it in SI (metric units) and try to convert in US units.
My splitter is driven by 3ph electric motor (3x400V, 50Hz) w. nominal power 5,5kW continuous, about 1400rpm.
Pump is 19 ccm/rev, over pressure valve set @200bar. So, about 27 lit/min flow.
At full pressure motor is loaded with 9,5kW (intermitent @200bar peak Pressure).
Hydraulic cylinder is 80/56mm dia (piston/rod), and at 200 bar splitting force is limited to 10ton.


Let put units in US:
Hyd. cylinder is 3,15/2,2in dia.
Motor 7,5HP (continuous).
Pump 1,159 cuin/rev, at 1420rpm give 7,1gpm
Pressure (max): 2900psi
With mentioned pump at 2900psi motor is loaded with ~13hp (motor is shortly overloaded 73% more then nominal power).

Now you can rough calcualate ratio:
your motor is 2hp, and as is 1ph, I doubt that you can overload it more then 50%, say 3HP max.
So 3/13*7,1...You can pull out 1,6gpm@2900psi max.

For that 1,6gpm@3450rpm, you have to buy pump with 0,11cuin/rev.
Honestly, this splitter will be very slooow (if you need force) or weak (if you want speed).

For example, if you find cylinder like I have (3,15in dia), it will move 0,8in/sec.

A 2 stage pump makes a lot of difference in the power required and work well on wood splitters. You can get 11 gpm at 600 psi or so and 2500 psi at a much lower flow.

 

[lennyzx11]

I made log splitter with electric motor drive.

As I'm from other side of the pond (as will my friend @Sawyer Rob tell), I'm not so familiar with your measuring system, so I'll explain it in SI (metric units) and try to convert in US units.
My splitter is driven by 3ph electric motor (3x400V, 50Hz) w. nominal power 5,5kW continuous, about 1400rpm.
Pump is 19 ccm/rev, over pressure valve set @200bar. So, about 27 lit/min flow.
At full pressure motor is loaded with 9,5kW (intermitent @200bar peak Pressure).
Hydraulic cylinder is 80/56mm dia (piston/rod), and at 200 bar splitting force is limited to 10ton.


Let put units in US:
Hyd. cylinder is 3,15/2,2in dia.
Motor 7,5HP (continuous).
Pump 1,159 cuin/rev, at 1420rpm give 7,1gpm
Pressure (max): 2900psi
With mentioned pump at 2900psi motor is loaded with ~13hp (motor is shortly overloaded 73% more then nominal power).

Now you can rough calcualate ratio:
your motor is 2hp, and as is 1ph, I doubt that you can overload it more then 50%, say 3HP max.
So 3/13*7,1...You can pull out 1,6gpm@2900psi max.

For that 1,6gpm@3450rpm, you have to buy pump with 0,11cuin/rev.
Honestly, this splitter will be very slooow (if you need force) or weak (if you want speed).

For example, if you find cylinder like I have (3,15in dia), it will move 0,8in/sec.

A 2 stage pump makes a lot of difference in the power required and work well on wood splitters. You can get 11 gpm at 600 psi or so and 2500 psi at a much lower flow.

This is what I was using as a premise that it may work.

Now to see what the theoretical tonnage force would be at the 600 psi and 3.6 gpm of the first stage.
EDIT
It appears to be 7536 lbs or 3.75 tons of force with a 4 inch cylinder.
Somewhat weaker than the advertised 5 tons of force of my DR 5 ton splitter.

Thank you ZJ_HR.
I have read and seen videos of many ideas that have come from your country. It is great to see the different ways that different societies handle a common task to all.

 

[4570Man]

This is what I was using as a premise that it may work.

Now to see what the theoretical tonnage force would be at the 600 psi and 3.6 gpm of the first stage.
EDIT
It appears to be 7536 lbs or 3.75 tons of force with a 4 inch cylinder.
Somewhat weaker than the advertised 5 tons of force of my DR 5 ton splitter.

Thank you ZJ_HR.
I have read and seen videos of many ideas that have come from your country. It is great to see the different ways that different societies handle a common task to all.

I had a 5 hp Honda gas burner on a 11 gpm 2 stage and I could only get to 2200 psi before the motor stalled in the high pressure side. The only hope of working is not hitting the high pressure very long. An electric motor will handle an overload pretty good for a brief time but I’d still look for a bigger motor.

 

[ZJ_HR]

I have 2 speeds with one pump.
You can see that shiny "cube" between operating handles, where manometer is.
This magic cube is "autospeed valve" which transfer oil to both chambers and push rod like it is plunger type cylinder. When load increases, cube opens front cylinder chamber and oil pushes full piston area at full splitting force.
For that it's necessary to have adequate ratio in piston/rod diameter.

I agree that in low power systems, like 2hp motor is, it's easier to go with 2-stage pump. Tandem pump cost more, need special hi/lo valve etc. Even with tandem pump, with 2HP power, it will have slow working speed anyway, just with faster reverse and faster "empty" forward move.

 

[denchen]

As a thought, is there a chance of `v` belt drive between the motor and the pump. By changing pully sizes the motor could be adjusted to the pump but at sacrifice in speed

 

[3Ts]

I made log splitter with electric motor drive.

As I'm from other side of the pond (as will my friend @Sawyer Rob tell), I'm not so familiar with your measuring system, so I'll explain it in SI (metric units) and try to convert in US units.
My splitter is driven by 3ph electric motor (3x400V, 50Hz) w. nominal power 5,5kW continuous, about 1400rpm.
Pump is 19 ccm/rev, over pressure valve set @200bar. So, about 27 lit/min flow.
At full pressure motor is loaded with 9,5kW (intermitent @200bar peak Pressure).
Hydraulic cylinder is 80/56mm dia (piston/rod), and at 200 bar splitting force is limited to 10ton.


Let put units in US:
Hyd. cylinder is 3,15/2,2in dia.
Motor 7,5HP (continuous).
Pump 1,159 cuin/rev, at 1420rpm give 7,1gpm
Pressure (max): 2900psi
With mentioned pump at 2900psi motor is loaded with ~13hp (motor is shortly overloaded 73% more then nominal power).

Now you can rough calcualate ratio:
your motor is 2hp, and as is 1ph, I doubt that you can overload it more then 50%, say 3HP max.
So 3/13*7,1...You can pull out 1,6gpm@2900psi max.

For that 1,6gpm@3450rpm, you have to buy pump with 0,11cuin/rev.
Honestly, this splitter will be very slooow (if you need force) or weak (if you want speed).

For example, if you find cylinder like I have (3,15in dia), it will move 0,8in/sec.

You have a very interesting splitter, but I can't quite figure it out, unless - - what length are your splits? It looks very short between the push plate and the wedge. It looks like lengths are adjustable and that when in use, the overall length of the splitter is about twice as long. Do you have a picture of it in use?

 

[lennyzx11]

You have a very interesting splitter, but I can't quite figure it out, unless - - what length are your splits? It looks very short between the push plate and the wedge. It looks like lengths are adjustable and that when in use, the overall length of the splitter is about twice as long. Do you have a picture of it in use?

I was looking at that also. It appears the end that the adjustable height wedge is fixed because of the linkage mounting on the stand.
But the other end also appears to not have much room in the hydraulic lines to move and looks to be mounted solidly to the blue stand also.

Maybe a “chopper “ that cuts across the round rather than splits?

 

[ptsg]

From what I can tell, the cylinder will slide back against a hard stop in operation. (Note the flange welded to the cylinder near the rod end port).

When in storage, it will simple slide forward to reduce the space used. Very clever and awesome idea.