Log Splitter Question

[soulasphil]

The pressure is the driving force.
GPM will dictate the speed of a complete cycle. The more GPM's, the cycle time is reduced/shorter.

I quite agree. That is the theory. Pressure is supposed to remain the same and increasing or decreasing rpms is supposed to change only the cycle speed. After a month of daily splitting I have once more seen that practice is slightly different. I usually run the engine slightly above idle about 1300 rpm. If there is resistance, I increase rpms to 1500 or even 2000 and split the difficult log. I find it difficult to believe the slight difference in speed is responsible for the better penetration and oil pressure has not been increased (no I'm not going to plumb in a gauge to make sure !).

 

[soulasphil]

I should have been more clear....I am wanting a stand alone unit, not pto.

Thanks.

Unless you have huge quantities of splitting to do, why not use a PTO splitter ? That's one engine less to worry about and you can still handle quite a lot of work.

 

[J_J]

The pressure is not there until a resistance is felt, the pump is now working againstr resistance, and as resistance increases, the pressure increases, until it meets the relief valve setting. Slowing the engine increases the cycle time. Some wood takes little pressure to split, and that stringy stuff with knots, takes quite a bit more.

What are you trying to accomplish by running the engine at a slow rpm. If time is not important, then speed of the engine shouldn't matter except to save fuel, and reduce noise.

 

[tatra805]

On the 22tons...

I am running a 25ton (5"/2", 300bar) homebuild splitter. Using it for splitting 1meter wood (say 3ft long).

Yes it will split as good as anything with a single wedge. Thats why i have made a permanent double wedge.

That learnt me that the wedge design is probably as important as the pressure. I made my wedges quite aggressive (short and wide) and in sequence (first vertical then horizontal).

I was splitting 10m3 (appr 3ft x 3ft x 30ft stacked) oak last weekend and had about 10 pieces which blocked due to knots etc. Because of the sequential wedges i then turn the wood 90 degrees and it goes through the splitter without a problem.

I'm running it from the tractor hydraulics. With the tractor at 1500rpm i get a cycle time of 18 seconds. not fast but that is for 3ft of wood split into 4 pieces.

I dont consider a stand alone or PTO pump splitter as we burn about 10m3 per year and that equals 4 to 6 hours of splitting per year with this setup.

The guy handling the wood can barely keep up with this. for a nice operation you need 1 guy feeding and 1 guy taking away and stacking.

 

[Redgoatea]

I love threads like this. I've always split the fun way with a maul and a wedge or two. Until a few weeks ago when a buddy of mine insisted I try out his 4 ton electric splitter 'cause it made it so easy'.

Holy cow what a piece of crap. It took two minutes to split each piece and would trip the breaker on straight fir. Perhaps I'll consider a larger one in the future when I get tired of the axe. 7

 

[J_J]

On the 22tons...

I am running a 25ton (5"/2", 300bar) homebuild splitter. Using it for splitting 1meter wood (say 3ft long).

Yes it will split as good as anything with a single wedge. Thats why i have made a permanent double wedge.

That learnt me that the wedge design is probably as important as the pressure. I made my wedges quite aggressive (short and wide) and in sequence (first vertical then horizontal).

I was splitting 10m3 (appr 3ft x 3ft x 30ft stacked) oak last weekend and had about 10 pieces which blocked due to knots etc. Because of the sequential wedges i then turn the wood 90 degrees and it goes through the splitter without a problem.

I'm running it from the tractor hydraulics. With the tractor at 1500rpm i get a cycle time of 18 seconds. not fast but that is for 3ft of wood split into 4 pieces.

I dont consider a stand alone or PTO pump splitter as we burn about 10m3 per year and that equals 4 to 6 hours of splitting per year with this setup.

The guy handling the wood can barely keep up with this. for a nice operation you need 1 guy feeding and 1 guy taking away and stacking.

300 bar is 4351 psi at sea level, and using your cyl of 5 in bore, and 2 in rod, = 85,432 lbs or 43 T.

If the cyl stroke is 36 in , and you have at least 10 GPM, the cycle time on extend is 18 sec, and retract is 15.65 sec for a total cycle time of 33.65 sec.

Double check your figures or double check mine.

 

[tatra805]

J.J.

I should have known...

going from experience i know its a waste of time checking your numbers so i checked mine

it should have been 200 bar instead of 300 of course; thats a typo

Gives me 25.335 ton for my cylinder.
Cylinder has a 750mm travel, say 29.5 inch. (last 250mm pushing your 1000mm wood is a waste of time as it is split completely before the cylinder extends that far anyway, wedge design dependent again)

To keep it easy (didnt find a good calculator for that online) my pump should have an output of approx 14gal/min to cycle in 18sec. (give and take a bit)

Dont know now if that is possible on my iseki or if i had a mine-is -bigger-than-yours moment and i have a 36sec cycle time and a 7 gal/min pump.

Anyway; thanks for pointing out my mistakes.:thumbsup:



On another note,...

I am keeping an eye on my pressure gauge while splitting and notice that most of the wood splits between 100 and 150 bar and then drops to around 70 or less to continue the split. Hard knotty pieces go over that value and IF it does not split at impact you mostly jump to release pressure and have a blocked piece. I saw this on different batches of wood in the last 2 years.

I dare to post more numbers and 125 bar / 5" cylinder value correspondents with 15,8 ton and is suspiciously close to the 4inch cylinder/200bar pump combo (16.something ton) as found on many commercial units. SO I am thinking manufacturers gamble on the fact that you will split 90% of your wood with a cheaper to build 16 ton configuration and be a happy customer. And i would kind of agree with that and really consider the fact if the price difference between 16 and 22ton is worth it for your usage.

 

[soulasphil]

I love threads like this. I've always split the fun way with a maul and a wedge or two. Until a few weeks ago when a buddy of mine insisted I try out his 4 ton electric splitter 'cause it made it so easy'.
7

I used to split wood like that except I used three wedges, until last year when I bought the splitter. The jump in productivity is enormous !