Fixing / Upgrading Log Splitter Press?

[Danneskjold]

Hi!


So I built a crude press out of a log splitter I bought. It originally came with a lawn mower engine, but it was kicking back on start up so much that I upgraded it to a HF Predator 6.5 HP engine.

View this content on Instagram

View this content on Instagram

(Ignore the music, I was just having fun on IG.)

The Pump itself was upgraded / replaced by the previous owner. I think it's a ~11 GPM dual stage pump from https://northernhydraulics.net/hydraulics-shop/log-splitters/two-stage-pumps . But there are no markings on the current pump, so I can't tell for sure and they all basically look the same.


Here's the rub: The aggressive half of the press-plate moves metal decently (but not necessarily straight). The flat plate barely moves metal at all. It may be too big, which I can fix.

But my motor basically never bogs down at all. With the exception of that split second where it switches from High Pump to Low Pump, the motor itself never struggles. The press will stop, won't be able to go any further. But the motor will run at the same RPM without changing.


So I'm thinking that there's more power to be had. Or is all of this normal behavior, and the only way to get more power would be to double the engine power and pump?


Thanks for any help!

 

[Stacy E. Apelt - Bladesmith]

Welcome to Shop Talk. Fill out your profile so we know where you live and a bit about you.

There are all sorts of possible issues.
#1 would be to check the by-pass adjustment to raise the pressure.
Other things may be fluid volume and condition.
There are some real gurus in Shop Talk on presses, so I'll let them give all the details.

 

[Ken H>]

Mostly what Stacy said - there are some gurus on this board who have LOTS of experience (not me) with forging presses.

A couple of notes, I watched your IG video and couldn't tell anything about it. Looks like it was working - the lever was pressed down, the ram extended to bottom. The lever was moved up and ram retracted. What more do you want? There was no motor noise - or the "music" playing was so loud the motor was not audible.

But my motor basically never bogs down at all. With the exception of that split second where it switches from High Pump to Low Pump, the motor itself never struggles. The press will stop, won't be able to go any further. But the motor will run at the same RPM without changing.

Here you say the motor shows a load when switching from high to low? That should happen when the pressure increases in the 300 to 600 psi range. The motor should continue showing a load after making the switch? What pressure is showing on the pressure gauge? I don't see a pressure gauge in the video. I don't see two high pressure hoses, with one to bottom of ram and one to top of ram.

When you say the press will stop, but won't be able to go any further - what do you mean by that? Is there still an air gap when the ram is extended as far as it will go?

What size cylinder do you have? It looks like it might be a 4" cylinder? Those pumps you linked are really expensive. You might look at Amazon for more reasonable prices - check item #B0C5RCQVJZ for a $60 pump that's got pretty good specs.

 

[Danneskjold]

Mostly what Stacy said - there are some gurus on this board who have LOTS of experience (not me) with forging presses.

A couple of notes, I watched your IG video and couldn't tell anything about it. Looks like it was working - the lever was pressed down, the ram extended to bottom. The lever was moved up and ram retracted. What more do you want? There was no motor noise - or the "music" playing was so loud the motor was not audible.

Here you say the motor shows a load when switching from high to low? That should happen when the pressure increases in the 300 to 600 psi range. The motor should continue showing a load after making the switch? What pressure is showing on the pressure gauge? I don't see a pressure gauge in the video. I don't see two high pressure hoses, with one to bottom of ram and one to top of ram.

When you say the press will stop, but won't be able to go any further - what do you mean by that? Is there still an air gap when the ram is extended as far as it will go?

What size cylinder do you have? It looks like it might be a 4" cylinder? Those pumps you linked are really expensive. You might look at Amazon for more reasonable prices - check item #B0C5RCQVJZ for a $60 pump that's got pretty good specs.

The ram moves. It does a little bit of work. It stretches the hot material on the drawing die half of the ram. But it doesn't seem like it has a lot of power behind it. It does practically nothing on the flat side of the die.

For example, I was taking billets of damascus out of my forge and drawing them out on the aggressive side of the die. Worked decent (other than my dies not pressing perfectly parallel*). Back in the fire, and put it in the flat side of the die. It can't even completely flatten the peaks down when the bar is straight out of the fire. It moves it a little bit, but doesn't get it flat or even drawn out past that.


The motor *only* seems to have a big load on it in that brief switchover. Not before, or after. And not when it's bottomed out on material. That's why I'm thinking that I'm leaving a lot of power on the table, and here asking the experts.

I'll need to wait for the snow to pass before I double check the cylinder size. The pumps I linked are what is on the machine. I've looked at getting bigger, more powerful pumps, however they ask for bigger motors, too.


*I could make this thing operate perfectly straight, but then I'd have to sacrifice its log splitting abilities, which I do use occasionally.

 

[Danneskjold]

Original Video, motor not at full throttle.

It had shaken out some shims that I used to align it with the pump, and shredded the spider connecting the gears. So I was testing it after fixing it.

 

[Ken H>]

Without a pressure gauge to tell what's actually going on there's not much way to have any idea of the problem. It really sounds like you're not putting up much pressure to the cylinder. It will flatten a billet on the drawing die - that's the front (outside) die that has very little surface area. On the back (inside) portion of the die it doesn't do anything to flatten the billet. That pretty much tells you there is almost no pressure at the cylinder. The control valve should have a bypass adjustment screw, or perhaps there is one on the pump (not usually)? The very first thing is to get a pressure gauge so you can tell what the system is actually doing.

Is that grey line coming out of the top of the control valve the hydraulic line going to the top of the cylinder that has pressure to extend the cylinder?

 

[Danneskjold]

Without a pressure gauge to tell what's actually going on there's not much way to have any idea of the problem. It really sounds like you're not putting up much pressure to the cylinder. It will flatten a billet on the drawing die - that's the front (outside) die that has very little surface area. On the back (inside) portion of the die it doesn't do anything to flatten the billet. That pretty much tells you there is almost no pressure at the cylinder. The control valve should have a bypass adjustment screw, or perhaps there is one on the pump (not usually)? The very first thing is to get a pressure gauge so you can tell what the system is actually doing.

Is that grey line coming out of the top of the control valve the hydraulic line going to the top of the cylinder that has pressure to extend the cylinder?

As best as I can tell, It goes Tank -> Hydraulic Fluid Filter -> Red Hose -> 2 Stage Pump (attached to engine) -> Long Black Hose -> Lever / valve (Branched to Cylinder) -> Medium Black Hose -> Back to Tank. I've never changed the fluid, checked the level, or even changed the filter.


I've never had problems splitting wood, but again, it's never bogged down / struggled on me while doing it. I'll look for control valve at the lever first, then the pump. But it'll have to wait til after the snowmageddon ends. Plus it's really cold and I don't want to go outside much this week, either.

 

[Ken H>]

You way up there in the frozen north land so I do understand what you mean by cold. It's really really cold down here also - it got down to 24°F last night. The water to my chickens froze up. At least the hens were ok, they have feather coats {g]

B0C7N4QZBD reducing bushing 1/2" X 1/4" NPT. While it's only rated at 350psi, I think it will handle the pressure gauge just fine. The one I have hasn't given any problems yet.

B0BCHM91N6 this is the 0 - 3000 psi pressure gauge.

B0BRCP8H5J is a Tee for the pressure gauge.

You really NEED a pressure gauge so you know what's going on.

 

[Danneskjold]

You way up there in the frozen north land so I do understand what you mean by cold. It's really really cold down here also - it got down to 24°F last night. The water to my chickens froze up. At least the hens were ok, they have feather coats {g]

B0C7N4QZBD reducing bushing 1/2" X 1/4" NPT. While it's only rated at 350psi, I think it will handle the pressure gauge just fine. The one I have hasn't given any problems yet.

B0BCHM91N6 this is the 0 - 3000 psi pressure gauge.

B0BRCP8H5J is a Tee for the pressure gauge.

You really NEED a pressure gauge so you know what's going on.

It got up to 24 degrees today. In the sun. It's not supposed to get above freezing for over a week. And we may catch another blizzard this weekend.


My forge is outside, and my grinder is on wheels so I can pull it into the driveway. I don't usually get too much done in the winter, but this is just miserable to even stand next to the fire in the open.



Thinking back to when I bought the log splitter, and looking through the box of parts that came with it, I realize that the previous owner replaced the switch, too. Maybe he never set it right.