log splitter plans

ByronMill · Nov 19, 2009

LD1 said:
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

LD1,

You mentioned that you connected the 11GPM pump to an electric motor. You did not state what RPM the motor was or voltage you were running at. 3600 or 1800 RPM motor? Voltage? 11 GPM would only be the case if using a 3600 RPM motor and amps alone do not tell about load. I assume probably 230V. 3PH or single?

LD1 · Nov 25, 2009

The electric motor was 3450rpm motor off an old craftsman air compressor. It was nameplate rated @ 5HP SPL and 13.5 Amps @ 230v/240v. It drew the 19-20 amps while in the split and didn't drop back below the 13.5 amp max until the split was done. That motor wouldn't last long with only a SF of 1.0.

Also it is a open motor. AS I mentioned, most air comp motors are and this also makes them not a good choice. Given the environment, you really want a TEFC.

ByronMill · Nov 25, 2009

Your information confirms what I was saying previously. That air compressor motor is not really 5 HP. 1 HP equals 750 watts, so 5 HP would be 3750 watts. Watts divided by voltage equals amps, so 3750 divided by 230 V equals 16.3 amps. Small motors like that are typically only about 80% efficient, in other words only about 80% of the electrical energy is converted into rotational torque. Therefore to get actual 5 HP at the shaft you need to input a 20% surplus. So 16.3 amps divided by .8 (to give the 20% surplus) = 20.4 amps. Therefore if you had a motor with a true output rating of 5 HP you would be fine, even with a 1.0 SF rating. The air compressor motor is in reality an "uprated" 3 HP. A true rated 5 HP motor with a typical nameplate efficiency of 78-82% would draw about 20 full load amps at 230 V. Best way to tell what a motor really is rated at is by looking at FLA and motor efficiency. If efficiency is not stated on the tag assume about 80%. Motor ratings on some motors are like Tons rating on splitters. How does anyone rate a splitter with a 4" cylinder at 27 tons of force? Same deal with the motors. How can a motor that only draws 13 FLA be rated at 5 HP? Fuzzy math?

General rule of thumb: (these are approximate values)

Every 1 HP @ 120VAC will draw 8 amps
Every 1 HP @ 230VAC will draw 4 amps
Every 1 HP @ 460VAC will draw 2 amps

I am not sure that the issue of an open motor versus TEFC/TENV is that big of an issue unless you are using it in a really dusty or dirty environment. If you keep it covered or out of the weather when stored there should be no real issues. If open motors hold up in woodworking applications they will surely provide acceptable service in a hydraulic drive. Heat is the biggest enemy of motors and open motors actually cool better than TE motors, unless of course they get packed full of dust.

I'm not challenging you or saying you are wrong. You are actually quite correct and on the right track, once you understand that air compressor motors and some "special duty" motors are actually over-rated.

skidsteer.ca · Nov 27, 2009

tnhomestead said:
Will a 3in cylinder work? Have one(3 by18) and scrap steel enough, want to add it to my small tractor 15 hp?
Have a set of plans from Mother Earth News from years ago, all will need is a valve and hose, maybe wheels and tires as well
thnx
didnt mean to hijack the thread
thnx

Think you better check what your max pressure is first. Ifyou have 2500fine, if its 1500

Ken

gould37 · Dec 2, 2009

Sorry for not getting back to you all sooner with an update. I had to split a tractor and fix a stump grinder and a chipper. I have not yet been able to locate all the goodies I need for my log splitter. Still looking for a reasonably priced motor and cylinder. If I can find the stuff in a reasonable amount of time, I will let you know how it turns out.

THANKS AGAIN FOR ALL THE HELP. THE INFORMATION IS GREAT.....

chainsawnut · Jun 18, 2010

hey guys pete here from down under I have been following your thread with much interest and enjoying it very much.I have been accumulating gear to build a splitter,I have a bunch of hoses,an 18inch by 41/2 inch ram a heap of steel and two smoky honda engines,1 at 6.8 hp and 1 at 10hp.
I have given up here in oz on the priceof 2 stage logsplitter pumps close to400 bucks,but have been viewing american prices even with the exchange rate they seem viable .
Because the detente valves can be bought and freighted in the same parcel.I have emailed a few suppliers so far no one has bothered to reply
.Can someone tell me I see haldex barnes pumps around the 170 180 range are they better quality than many that show no brand name.
I was thinking of the 16gpm pump but if an 11 will do the same job and let me use te smaller motor I would prefer that.
Illness is slowly robbing me of strength but I love my old saws I burn wood and I want to stay self sufficient for as long as I can .Being only 51, I want to hang around for as long as I can.
I have some pumps but they are rather large edbro pto units are these a hydraulic pump or not.
They have gear drive but I felt I could cut away the body and fit pulley drive,there ondition is unknown as they along with most of the other bits were in my late fathers shed.Thanks for any replies and does anyone have an email adress for surplus center that will get to them,they show some great prices cheers

Oliver1655 · Jun 25, 2010

The Haldex 2 stage pumps are proven performers for log splitters. With a 4 1/2 in dia cylinder you can get by with the 11 gpm pump but you will be at the slow side of splitting. I am still using a 4 in dia cylinder with a 16 gpm Haldex 2 stage pump and find it to be a good match. I am using an 11 hp Greyhound engine I purchased through Harbor Freight and only have to run it at a little above an idle. This keeps the noise level way down and saves a lot on fuel. The engine is electric start but will start with only 1 or 2 pulls.

richmatz · Sep 6, 2010

Interesting reading, I made a log spliter in high school, my first lesson was that there is a right and left hand hydraulic pumps.

So now I am going to build a splitter that will attach to my skidsteer. I know thats an expensive hydraulic pump... So i put an extra 10 hours a year on the motor.

The machine is a bobcat s300 with hi-flow (37gpm) at 81hp or something like that. The machines pressure relief is at 3300PSI
Suggestion on a ram?
Suggestion on a valve?
pressure hose diameter?
PHOTOS?

there are a few manufactures of these attachemnts out there. They all want around $2500 Here is a link to the best unit that I could find I would buy this if i didnt have the capabilities to build one. The only problem with this unit is the shape of the wedge when splitting hard woods.
Log Splitter for Skidsteer / Skid Steer / Loader / Compact Tractor - Quick Split - fits Bobcat and most other brands

I figure for $1500, not including my time I can build one.
Your ideas and comments are appricated!

J_J · Sep 6, 2010

If you have 37 GPM, why do you want another pump? Do you have QD's on the front of the machine? If the SS is only running slightly above idle, you should have enough hyd to get the job done.

richmatz · Sep 7, 2010

JJ
Thanks for the comment back, I was going to use the bobcat as the source of hydraulic pressure...Yes there are quick disconnects on the front of the machine, I have everything except the ram, valve and hoses.

J_J · Sep 7, 2010

Here are a few SS splitters.

Last splitter is a double ram log splitter.

2458n · Sep 11, 2010

Find a used three point log splitter from a tractor. Throw it on the ground upside down. The skid steer plate can be sourced from Bob Cat. Cut the top of the three point hitch off and weld the plate on the "draw bar" part. You will end up with a plate that attaches to the skid steer with a log splitter sticking out the front upside down. The cylinder is plumbed into the normal hyd. quick connects. On a older Bobcat 743 you can not have more fun. Large 3-4 ft. dia. pieces can be clamped picked up and moved,or simply split. Sure you might have to split a piece that large 8 to ten times but you never lift a log or leave the seat. The tip of the log splitter beam can be used to push the pieces around keeping your work area clean. The one we are currently using cost less $500 to build using auction found parts.

richmatz · Sep 12, 2010

This last week I bought everything off a 34ton horizontal/vertical commerical splitter from the rotation/pivot point up from a logsplitter manufacture. I didn't get the motor, pump, reservoir, trailer. I have the bobcat plate with a 6"x6"x30' box beam welded to it for pushing the burn piles. I am going to cut the box beat at 4' - 6' from the bobcat plate and attach the item I bought and this will be a horizontal/vertical splitter. I will them need to get 2 hoses made from the bobcat to the splitter valve and back again....there are lots of photos of skid steer splitters out there to learn how to route the hoses correctly. I hope that next weekend I will have this running. We had a low temperature last night of 33 degrees.

Photos to follow as I complete this task

ProfessorGT · Nov 9, 2010

Gents,

While being new to this forum, I have been researching and planning my own custom splitter for a while now. I have attached a chart which should help with some of the calculation noodling necessary to properly plan out what you want. It shows some typical cylinder cycle times with various pump sizes, it shows what the real splitting force will be with various parameters, and it also shows the HP requirements for various pumps, using Internal Combustion Enines (not electric motors, which are not of interest to me on a project like this). BTW, it also has the source links for these calculations/formulas.

My splitter is going to be a 4 X 24 X 2" cylinder (already purchased), a Prince 3000-1 series valve (also already purchased), and a 16gpm 2-stage pump (still looking for the best deal here).

If you look at the charts I attached, YES, you do get quicker cycle times by going with a 22 gpm pump, however the pump is almost twice the price of the 16 gpm pump (for some reason the jump from 16 gpm to 22 gpm causes the pump price to get insane), AND then you would have to go with a larger engine, which is more expensive and consumes more fuel as well!

The 16 gpm pump will work best with a 9hp engine (I.C. - not talking electric motor here), but the 22gpm would require at least an 11hp - preferrably a 13 hp piece.

So, from an economical standpoint I will stay with the 16 gpm pump. Now, with that said, it just so happens that I already have 2 12 hp engines, so it's a no brainer to use one of those and not have to spend any extra cash on a different engine. In fact I actually have a 9h engine, but it does not have an electric starter, nor an alternator, like the 12hps do. I want the electric start capability, and also the ability to have 12v power for lighting and a winch, so again, the 12hp is a no-brainer for me. The added bonus is that I don't have to work the engine nearly as hard, so it will use less fuel, and it will theoretically last longer too.

Right now I'm working on the log lift design, and looking here for info on that. I believe I saw a thread on that topic, so I'll get there.

Elsewhere I saw a post that I responded to just a bit ago, and I mentioned that I have purchased a couple of different sets of plans. I'm willing to trade plans with others if they have different ones than I have - Let me know if there is any interest in doing so via PMs.

Ah yes, choices, choices, choices! Hey if there were no problems to solve, and everyone was the same, where would we be? Life would be so boring. Celebrate our creativity, and build it!

cosmintrif · Dec 22, 2010

Diamondpilot said:
I built one 4 years back to run off my tractors hydro system. I used a 4"x24" stroke. My hydro system is 7 gallons per minute but I am sure that is probably at PTO speed or somewhere near. I have split about 100 ricks with it and 1200 rpm on my tractor works fine even though my PTO rpm is 2250.

As you can see I utilize my 3 point hitch I made out of a Ford Ranger Hitch for the attachment. I also made it go long ways out the back of the tractor so two guys can work from it. I added the wood log cradle later which is a must and I also made a adapter in the 3rd picture that allows it to double as a shop press.

Chris

Hi I made this log splitter at home if someone need details, please don not hesitate to contact me. This was a test. In the mean time i made some reinforcements welds at the wedge support. The wedge will have height adjustments.
YouTube - YouTube - Crapator de lemne Campenesti.flv

Maritimer · Jun 30, 2011

Hi Fellas,
Ive ben reading this thread also for a bit trying to fing the best combination for my splitter I am about to build. I have built a few in the past, each time tweeking it a bit to better suit me. I have a 8hp Honda for a motor. I would like my cycle time to be quite quick, at the same time I don't want to loose any power. If I get the 4.5in cylinder with a 2"ram(24in stroke) and the 16galmin pump would that be a good quick combination? Anyone have the cycle time of this? If I used a 4" instead, with a 2"ram...would that be faster? I read that J J found this LSR 3050 valve that could double the cycle times. Could this still be used with the Haldex 16g/m pump?

Thanks guy's for all your input. I'll look forward to all your comments.