log splitter ( i know its the wrong weather )

[dannyp]

been thinking about starting to desing maybe even build it intime for winter.

i've built a horizontal and vertical hydralic before, the vertical is good for splitting big rings and very useable, the horizontal tho i think has a lot of room for inprovement, being hydralic it's slow to speed it up means running big pumps ( 32cc/rev ) but this means it now only powerable by ether tractor or reasonable size diesel.

so i'm thinking abount building a purely mecanical one, storing the energy up in a flywheel and transmiting it to a cranck through some sort of clutch i'm thinking some flavor of clutch like found in a gillotene or mecanical punch any ideas how i chould make or where i chould aquire / or bu such a thing from ?

 

[WorkshopChris]

like found in a gillotene or mecanical punch

To give you an idea of the size of things and the amount of power required, our old 10-ton presses had flywheels around 4" wide and 30" diameter, at around 100rpm.
With that weight the potential for things to go wrong is huge.

 

[gaz1]

i wouldnt want to use this type

 

[WorkshopChris]

Will be watching this with interest the designs based on a rack and pinion look promising.

 

[dannyp]

so far the easyest looking options are looking rack pinion or air

going allong with my usual style i will be makeing sure there is no shortage of power but i plan on encaseing and garding it, a lot of wood splitters just look lethal and it the spit the log out and it dose happen there is potential for mutch pain.

 

[knighty]

if oil is slow why not go with oil and air powered ?

have a double acting piston with air pressure on one side and oil on the other
(edit - separate piston from main one, this is just to act as a low pressure oil feed - sorry that wasn't clear before)

you'll need 2 leavers (or a fancy leaver) to work your main piston, so you use that air powered oil first (to move ram and take up spaced) and then use electric pump fed oil when you need real pressure

or... do the same with one motor with two pumps on it, 1st low pressure but high flow pump, and then high pressure but low flow pump second ?
(pressure release valve on high flow pump so it doesn't stall the motor)

or, you could use both pumps at the same time, but cut the flow from the low pressure one with a valve once the free space had been taken up ?

 

[dannyp]

Will be watching this with interest the designs based on a rack and pinion look promising.

simplicity and efficency rack and pinion looks a winner, i chould use air but i'd be basicly makeing an horizontal air powerd powerd slide hammer and runnng it of a road compressor but thats loud and likes diesel so sort of defeating the point so rack and pinion hunting i may a go

 

[dannyp]

if oil is slow why not go with oil and air powered ?

have a double acting piston with air pressure on one side and oil on the other
(edit - separate piston from main one, this is just to act as a low pressure oil feed - sorry that wasn't clear before)

you'll need 2 leavers (or a fancy leaver) to work your main piston, so you use that air powered oil first (to move ram and take up spaced) and then use electric pump fed oil when you need real pressure

or... do the same with one motor with two pumps on it, 1st low pressure but high flow pump, and then high pressure but low flow pump second ?
(pressure release valve on high flow pump so it doesn't stall the motor)

or, you could use both pumps at the same time, but cut the flow from the low pressure one with a valve once the free space had been taken up ?

i dont think air over oil would help as the splitter ram would haave to be double acting so it would want to be air over oil advance to the long and air over oil retract say running at 125 psi in a hydralic system thats nothing im not sure but i think it would have problems pushing the oil back fast enough to make it worth the effort.

i'm likeing the rack pinion atm nice simpel mecanical

 

[gaz1]

heres some details from other builds

 

[Dodge20]

Just no.

 

[Wendelspanswick]

My favourite, aptly named the Widow Maker!

 

[Maker]

i'm likeing the rack pinion atm nice simpel mecanical

Stair lifts can often be picked up cheap or even free and have a few meters of racking, a pinion, worm gearbox and a nice torquey DC motor.

 

[angellonewolf]

dont know if i would trust my self using one of the widow makers even the blokes look like they are very nurvus when in use

 

[Bill Edwards]

The kinetic type using a rack looks like the best method by a long way. Perhaps a little more thinking required for the build but I don't think anything else that's safe and cheap can come close for speed.

 

[dannyp]

The kinetic type using a rack looks like the best method by a long way. Perhaps a little more thinking required for the build but I don't think anything else that's safe and cheap can come close for speed.

thats exactly what i'm thinking, its a lot faster and more efficent than hydralic type, i'll encaseing the splitter more and makeing some form of shute to feed it with and have it fire the split wood straight into a spud box for storage. you can really see in the youtube vidios who actualy uses the spliters as if your splitting loads of wood double handeling is not an option

 

[Gareth J]

I thought about making a kinetic splitter for a good while, lots of options and YouTube vids^^ to rob ideas from.

However. I've not seen one video showing how one deals with a gnarly, knotted lump. Or even just a bit of wood with a "Y" to it. What happens if one is presented with something too twisted/hard to handle?? Something has to give.

In the end I went out and bought a 7ton baby horizontal, electric, hydraulic thing from the local place. Cost about £200 which I'd have ended up spending more on bits if I'd made my own. Being electric it's pretty quiet and is much quicker to use than I thought. It has a fair go at even the most knotted lumps and importantly, on the rare occasion it doesn't manage to make a split, the oil pump just stalls - no drama, release, reposition and try again.

Maybe it's not such an issue for you as you said you've got a couple hydraulic ones so you can be a bit picky about which logs you split with what but it worked for me.

 

[Ton-up]

What about a vertical one where a heavy weight with a wedge drops fast into the timber and then a hydraulic ram takes over to finish?

 

[Bill Edwards]

What about a vertical one where a heavy weight with a wedge drops fast into the timber and then a hydraulic ram takes over to finish?

I think it would need to be very, very heavy (to the point of being impractical).

 

[Bill Edwards]

I thought about making a kinetic splitter for a good while, lots of options and YouTube vids^^ to rob ideas from.

However. I've not seen one video showing how one deals with a gnarly, knotted lump. Or even just a bit of wood with a "Y" to it. What happens if one is presented with something too twisted/hard to handle?? Something has to give.

In the end I went out and bought a 7ton baby horizontal, electric, hydraulic thing from the local place. Cost about £200 which I'd have ended up spending more on bits if I'd made my own. Being electric it's pretty quiet and is much quicker to use than I thought. It has a fair go at even the most knotted lumps and importantly, on the rare occasion it doesn't manage to make a split, the oil pump just stalls - no drama, release, reposition and try again.

Maybe it's not such an issue for you as you said you've got a couple hydraulic ones so you can be a bit picky about which logs you split with what but it worked for me.

One of the videos above has a kinetic one running from a pretty small briggs and stratton. If the wood is too tough it can either kick the rack out of engagement or being small the engine can stall.
In any event, it would be easy enough to incorporate a slip clutch of some sort into the design.

 

[Gareth J]

One of the videos above has a kinetic one running from a pretty small briggs and stratton. If the wood is too tough it can either kick the rack out of engagement or being small the engine can stall.
In any event, it would be easy enough to incorporate a slip clutch of some sort into the design.

Yup, something can be designed in to let it stall/slip for sure, it needn't be catastrophic. But I can't see any examples of anyone attempting anything other than nice straight grained timber with one. How do they fair? My suspicion is that given something with a reasonable knot in it, they would use up a big chunk of their stored momentum splitting whatever is splittable so by the time the blade gets into the guts of a knot it's already acting at reduced capacity and it stops. Where a hydraulic one would keep on driving at full force.

Despite this, I do really like the idea of kinetic splitters though!