Log-Splitter Press / Cape Cod

Not Steve

Not Steve

Joined
Apr 12, 2021
Messages
22
Hey all, it's Bill and Jeremiah, back again to share amazing stories of forging adventure. This thrilling instalment: Tales of the Log Splitter Press. Or, "I'm tired of hammering Damascus."

BIG BLU was a littttttle out of our price range, so enter the log splitter. We're probably all familiar with this conversion. Like most of its kin, the log splitter does its thang by pushing a floating plate against a sharp, stationary wedge. Any logs unfortunate enough to be caught between are split as the force against the wedge overcomes the wood's molecular bonds.

To convert the splitter to a forging press, we welded a solid, rectangular, steel block in front of the sharp wedge. On the moving side, we welded a smaller steel block. They weren't quite flush, so we welded a triangular shim to the moving block. Wobble was a big problem at the climax of crushing - the stationary block wanted to rise up and be free. And take a lot of force with it. We dashed its dreams by strengthening the weld between the stationary block and the log splitter's bed. The triangular wedge also helped by contributing a downward force vector.

Early tests are looking good! It's not BIG BLU, but is surprisingly powerful. When the planes meet, they were flush and stayed put. Hot metal was smushed.

Cost: One Wen Lumberjack Log splitter: $277. The metal blocks looked pricey (just because of their size), but I think Jeremiah may have found or conjured them.

This our first build. We'd appreciate any advice or feedback to improve it.

Pictured: Jeremiah's press, vacationing in scenic Holland.

EDIT: We shot some video if anyone's interested. Originally, I intended it to punch up my tinder profile, until I realised that it's Thor that ladies want - not the guy making his hammer.
 

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Interesting, is that the 6.5 ton unit? What diameter is the cylinder? Just the OD is fine, the internal diameter can be estimated from the OD. What hp is the motor? I see it says 15 amps, that's around a 1 hp?
 
Will it work somewhat - yes. Will it work well - no.

The biggest problem is speed. Those are really SLOW. They are usually very overly optimistic with the HP and tonnage ratings.

BTW, send me an email, I still have a motor to send to you.
 
I built a similar unit for the time being. It works...It's not fast.....It's not perfect, but it's faster than hammering. I believe mine was advertised as a 6 ton unit. I have found that 3/4" diameter drawing dies work well.

However, i already plan to piece together parts for a full 20-ton+ press build... so there's that.
 
These small electric home log splitters don't have a pressure gauge. The PSI is pretty low, IIRC.
I looked that unit up and they list it at 5 tons and 2900max. PSi, but that is in the stalled mode. The cycle time is 14 seconds - 9 seconds forward and 5 seconds return. It only has .6 gallons of oil, too.
 
Ken H> said:
Interesting, is that the 6.5 ton unit? What diameter is the cylinder? Just the OD is fine, the internal diameter can be estimated from the OD. What hp is the motor? I see it says 15 amps, that's around a 1 hp?
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Hi Ken, thanks for your questions. Here it is. It's advertised as 6.5 tons with a 2.5 HP motor—but (as I've learned from you guys here), I don't know much of that I'm actually getting. If I understand the unit's specs, the cylinder is 14.75 in. I'm…actually not sure what the relevant cycling is. 😅
 
Stacy E. Apelt - Bladesmith said:
Will it work somewhat - yes. Will it work well - no.

The biggest problem is speed. Those are really SLOW. They are usually very overly optimistic with the HP and tonnage ratings.

BTW, send me an email, I still have a motor to send to you.
Click to expand...
Hi Stacy, yes you're bang-on. It smushes metal reasonably well. So far. And slowly (especially in reverse).

Based on the YouTube videos I've seen, the alignment is pretty good…for a log press conversion. It took a lot of work to get there, and just yesterday some welds gave out, and we've now secured it with a giant U-bracket (not pictured in the photo). Precision is not a design requirement for a log press. 😭😭😭

Thanks, that'd be awesome! I'll hit up, yes.
 
Shane Csepp said:
I built a similar unit for the time being. It works...It's not fast.....It's not perfect, but it's faster than hammering. I believe mine was advertised as a 6 ton unit. I have found that 3/4" diameter drawing dies work well.

However, i already plan to piece together parts for a full 20-ton+ press build... so there's that.
Click to expand...
Hi Shane - yeah, it's like your first forge is always a practice forge. Can you post a photo? We're real interested in other people's experiences with them.

20 tons…wow, cool. Can you share your plans there? (Edit: That I would attempt something requiring that skill level. Jeremiah might, ha.)
 
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Stacy E. Apelt - Bladesmith said:
These small electric home log splitters don't have a pressure gauge. The PSI is pretty low, IIRC.
I looked that unit up and they list it at 5 tons and 2900max. PSi, but that is in the stalled mode. The cycle time is 14 seconds - 9 seconds forward and 5 seconds return. It only has .6 gallons of oil, too.
Click to expand...
Thanks for checking that out. I'm always concerned it will break itself apart - splitting logs incurs a potential force, followed by a release. When I'm smushing metal, it just keeps pushing until I reverse it. It's interesting to see the actual cycle times - I guess it only feels like the return is slower, because there's nothing to do but watch it go. I'm thinking they move slowly as an inexpensive way to increase power? That's interesting (and not surprising) that horsepower is considerably lower in (what I assume is) a real-world situation. If I'm not asking too many questions, is that the oil used as hydraulic fluid?
 
Not Steve said:
Hi Ken, thanks - what does the "tons" actually (or supposed to) refer to?
Click to expand...
Measure the OD of the cylinder, the length of cylinder doesn't really matter for calculation of tons pressure. The "tons" referred to in a hydraulic press is the amount of pressure the cylinder will press down. i.e., if the calculations show the hydraulic cylinder will create 13,000 lbs of pressure, then it's a 6.5 ton press. Remember, an American ton weights 2,000 lbs, so divide the amount of pressure by 2,000 to get tons.

In your case, if the max is 2900 psi (higher than I would have expected with a log splitter), and the claim is 6.5 tons, it's most likely a 2.4" cylinder which will measure around 2.6" OD. 2.4" is an odd size for a hydraulic cylinder, but it might be special made. Can you get to the cylinder to measure the OD? That would tell us something.

The actual calculation is the (area of piston inside cylinder X psi) / 2,000 to tons created.

For building a forging press in the 12 to 16 ton range perhaps the easiest and least expensive would be to follow Coal Iron's setup for their "12" ton "H" design press that is actually a 9 ton since it only has a 3" cylinder. The frame is easy to build with welding, using a 4" cylinder for $133 shipped works good.
 
Ken covered the basics of calculation max tonnage. I can only say that those little splitters are unlikely to deliver the stated tonnage or max PSI.
The third parameter is the pump flow rate. A good forging press needs at least 11GPM. 16 is really good. The only way to run a bigger flow rate is use a bigger power source (motor). The small motors running those home splitters has to take a good while to pump up a cylinder full of oil. That is why the cycle time is in the 15 second range. A good forging press runs about 1 IPS with a cycle time of 3 seconds or less.

Another factor is the pressure/time curve is not really a linear thing. Squishing at 5 tons for 5 seconds won't do what swishing at 25 tons for 1 second does.

You have mentioned the die plate rising up. The ram should be on a beam/frame and held in line with guides/brackets/gibs. On a single beam press, these are "L" shaped brackets that go around the edge of the frame so the ram can't move any direction but exactly inline with the shaft and cylinder. On a forging press, this is very important, as any vector will greatly diminish the applied tonnage.
 
Ken H> said:
Measure the OD of the cylinder, the length of cylinder doesn't really matter for calculation of tons pressure. The "tons" referred to in a hydraulic press is the amount of pressure the cylinder will press down. i.e., if the calculations show the hydraulic cylinder will create 13,000 lbs of pressure, then it's a 6.5 ton press. Remember, an American ton weights 2,000 lbs, so divide the amount of pressure by 2,000 to get tons.

In your case, if the max is 2900 psi (higher than I would have expected with a log splitter), and the claim is 6.5 tons, it's most likely a 2.4" cylinder which will measure around 2.6" OD. 2.4" is an odd size for a hydraulic cylinder, but it might be special made. Can you get to the cylinder to measure the OD? That would tell us something.

The actual calculation is the (area of piston inside cylinder X psi) / 2,000 to tons created.

For building a forging press in the 12 to 16 ton range perhaps the easiest and least expensive would be to follow Coal Iron's setup for their "12" ton "H" design press that is actually a 9 ton since it only has a 3" cylinder. The frame is easy to build with welding, using a 4" cylinder for $133 shipped works good.
Click to expand...

Hi Ken, thanks for the information. I'm a math guy, so I'm vibing all that. Jeremiah measured the diameter; its 30mm.

We've got a frame, and that's out next project - where can I find Coal's set up? I think our frame is rated for 12 tons - it's a hand-cranked one.

Thanks, Bill & J
 
Stacy E. Apelt - Bladesmith said:
Ken covered the basics of calculation max tonnage. I can only say that those little splitters are unlikely to deliver the stated tonnage or max PSI.
The third parameter is the pump flow rate. A good forging press needs at least 11GPM. 16 is really good. The only way to run a bigger flow rate is use a bigger power source (motor). The small motors running those home splitters has to take a good while to pump up a cylinder full of oil. That is why the cycle time is in the 15 second range. A good forging press runs about 1 IPS with a cycle time of 3 seconds or less.

Another factor is the pressure/time curve is not really a linear thing. Squishing at 5 tons for 5 seconds won't do what swishing at 25 tons for 1 second does.

You have mentioned the die plate rising up. The ram should be on a beam/frame and held in line with guides/brackets/gibs. On a single beam press, these are "L" shaped brackets that go around the edge of the frame so the ram can't move any direction but exactly inline with the shaft and cylinder. On a forging press, this is very important, as any vector will greatly diminish the applied tonnage.
Click to expand...
How do you guys know so much about this stuff? Thank you for the specifics. I'll send a photo of the bracket we put on it - hopefully we've got that right. Is it OK if we send a photo? (A photo of the press!) Thanks again.

Bill
 
Hopefully, 30mm is the shaft size, not the cylinder size. The ram piston is larger than the shaft.
If it was the actual cylinder size, that press can only deliver 1.7 tons of force. The cylinder should have the size on it somewhere. To get a guess, measure the OD of the entire cylinder and subtract about .25 inch. If it measures 2.25"/58mm OD the cylinder ID is around 2.00"/50mm, which is a 1" radius, which is 3.5 sq.in.. This would make the press just a tad over 5 tons.
 
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Actually if the pressure actually is 2900 psi, and the cylinder is 3.75" OD, making it a 3.5" ram size, that would give around 14 ton. Since you mentioned measuring the OD at 30mm or 1.181", that would give the ID of the cylinder a tad less than 1" diameter, which at 2900 psi would be right at 1 ton (2,000 psi).

Stacy is right that usually a 12 to 15 GPM at 3600 rpm 2 stage pump is used. If the pump is driven by an 1800 rpm motor the flow is half that. Remember, the 2 stage pump is spec'd at low pressure (usually <600 psi) for full flow, then as pressure rises above the set point the flow drops to around 2 or 3 GPM at high pressure. This allows the press (or log splitter) to move faster while closing, then as the pressure increases the flow rate drops make the ram travel much slower, which is ok since it's only moving a small amount while squishing the billet (or splitting log).

Take a look at this site: https://coaliron.com/collections/hydraulic-forging-presses for look at the 12 ton press (actually only a 9 ton press with a 3" cylinder, false advertising?)

If you're planning to build a press, take a look at their presses, and I would focus on the 12 ton "H" frame. While the "C" frame is nice, it's more expensive and had to be built MUCH stronger to handle the stress. I can provide links to a 4" cylinder for $133 shipped, and a few other ideas. I'd look for a 3hp 3600 rpm motor, but a 2hp 1800 rpm motor works pretty good. For hobby use I think a 5 gal oil tank would work just fine.

I doubt there is anything you'll be able to use from the log splitter to build a press.

I forgot to add these links before. To calculate tons, :https://www.baumhydraulics.com/images/calculators/cyl_calc.htm

Here's a link to play around with for calculating ram speed to size the pump: https://www.baumhydraulics.com/images/calculators/cyl_speed.htm

Anything over 1.5" IPS ram speed will work pretty good. The cycle time and full stroke time isn't as important because when you're working a billet the ram is retracted only an inch or so to move billet and back down. Even 1 IPS ram travel speed is only 2 seconds cycle time.
 
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Thanks for the catch, Ken. I left pi out. Area=piRsquared. I was working with 3.5" area, but wrote it as diameter. I fixed it.

I rechecked the math and it would be a 2": cylinder to make 5 tons.
 
Yep, 2" diameter cylinder at 3200 psi would be 5 tons, or 10,000 psi. Pi ((3.1416)*1^2) * 3200 = 10,053 psi or 5 ton.

A 2" diameter cylinder at 2900 psi would be (3.1416 * 1) * (2900) = 9110 = 4.56 tons which would round off to 5 ton for marketing purposes. Remember, they only have a 30mm OD cylinder (post #14) which is only around a 1" cylinder which would be about 1 ton (2200 psi)
 
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