Mechanical log splitter (not hydraulic)

Has anyone in OZ seen one of these?


Check out this video on YouTube:

YouTube - Broadcast Yourself. v=MpmuZwdlPrc&feature=youtube_gdata_player

It's a DR rapid-fire log splitter. It's not hydraulic but 2 flywheels attached to a pinion gear. There is a neat animation in the video showing the cam leaver and rack/pinion.

I was looking at buying or building a hydraulic splitter however this system makes a hell of a lot more sense.

Do we have these in OZ yet?
It seams like a very fast way of splitting firewood..
It would be a straight fwd construction with farming the rack/pinion and balancing the flywheels to a machine shop. Time is always a factor I guess and it would be cheaper just to buy it... Unless you wanted to beef it up a lot. One of these with a 4 or 6 way splitter would be great... Hook it up to a PTO on a tractor and you would be splitting fast.

And that URL was no good..

YouTube search DR rapidfire log splitter if your interested guys/gals.

[ame=http://www.youtube.com/watch?v=MpmuZwdlPrc]Under the Hood - DR RapidFire Log Splitters - YouTube[/ame]

Very different! But the rack, pinion and return spring will give trouble eventually.

I have been unable to watch the youtube video of this product so I may be wrong, but I have one major concern with this splitter.
I have had experience with other flywheel driven equipment in the course of my trade, namely mechanical punch and shears, mechanical guillotines and mechanical brake presses. These all had one thing in common - they could only perform a full stroke and once engaged had to perform their full cycle, ie. they could not be stopped once engaged. In the case of a guillotine or punch they are guarded (or should be) not allowing fingers etc to be present when the hammer falls. Wood splitters by their very nature are virtually impossible to guard, so the notion of a knife that cannot be topped once started and may not be able to be reversed mid stroke does not excite me one little bit.
Hydraulics are infinitely variable in their speed of operation and have a built in overload mechanism in the form of a pressure relief, something that mechanical flywheel actuation is unlikely to match. Let us not forget also that most hydraulic splitters have a dual stage pump allowing for both high volume/ low pressure and low volume/high pressure modes, (fast under no load such as the return stroke and high power but slower speed when grunting through a tough knot). Furthermore our eucalypt species are far tougher than most north american timbers so the possibility of a splitter stalling out and needing to be reversed is far more likely.
End of the day, a flywheel does not create energy but only stores it and there is still the same 6hp available to do the work, the flywheel provides its stored energy in a burst, much like a capacitor really allowing intermittent higher loadings. This suggests to me that this splitter will perform well in timbers that shatter readily and not so well in those that have a tighly twisted grain requiring full power over the whole splitting cycle.
I am not an overly big wood splitter fan as such and would only use them on tough timbers so for me I would tend to rate grunt over speed, plus I value my fingers and am not keen to place them in the way of a mechanism that is potentially not variable nor reversable.
Hydraulics took over most areas of industry for this very reason.

The operator has a lever to engage/disengage a rack & pinion.

The timber in the demo is straight grained & looks soft compared red stringy.

It is quick but I'd like to see a demo with real wood.

Quote:

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Originally Posted by Cliff Rogers

It is quick but I'd like to see a demo with real wood.

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:2tsup:

You mean a cranky grained lump of redgum? LOL. I've bent wedges on that stuff. Not yet had to burn one out but have come close.

Further to what Karl was saying it looks like it does 6/7/8 turns of the flywheel for a stroke which is a bit different to a single rev of a flywheel to give up its energy to punch or shear or whatever the machine does, I'd suspect that the flywheel in this case is needed to keep the motor going thru its non power strokes (exhaust/intake/compression) the flywheel would give some of it's energy back to the motor during the these strokes and to splitting then consume power during the power stroke and to splitting.


Pete

Quote:

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Originally Posted by pjt

Further to what Karl was saying it looks like it does 6/7/8 turns of the flywheel for a stroke which is a bit different to a single rev of a flywheel to give up its energy to punch or shear or whatever the machine does, I'd suspect that the flywheel in this case is needed to keep the motor going thru its non power strokes (exhaust/intake/compression) the flywheel would give some of it's energy back to the motor during the these strokes and to splitting then consume power during the power stroke and to splitting.
Pete

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You are correct in your thoughts regarding flywheel effect inasmuch as the flywheel gives up its energy during the splitting stroke and is then "recharged" during no load periods however the task of keeping the motor running during the intake, compression and exhaust strokes would largely be handled by the engines own flywheel, (a 6Hp. Subaru engine - sold in Australia under the Robin brand, very common on concrete vibrators, compactors and generators).
You are also correct that most punches and guillotines connect the flywheel directly to the load, (typically through a cam or crank arrangement), rather than the rack and pinion system, they also use larger flywheels at a slower speed, so it more or less equals out to the same result.
The concept of this splitter is an interesting one, for me though, based on what I have seen so far, the drawbacks seem to outweigh potential advantages.
I would like to see one in operation on our hardwoods though.

The priniciple behind this method of splitting wood isn't new. Remember the old small square hay balers , they had a large flywheel driving a gearbox with a plunger arm rotating and moving up & down a chamber to cut & compress hay.

Old timers had a trick of converting these balers into a wood spliters by attaching a large wedge to the plunger, modifying & reinforcing the chamber so a log could be dropped in from the top but not pushed out the back, once busted the wood would fall through the bottom. Quite a serious "redneck log splitter"

cheers,
Dean.

Dunnings Woodyard in Kew (Melbourne) had a couple of these type machines for years looked like a 50's manufacture bloke swore by them, reconned for speed they were hard to beat. Not sure what power motor he used but looked to be a fair size 3 phase motor.

They did not look all that safe but split yellow stringy and redgum with ot problems. Trick is to have the logs the optimum length for the stroke of the machine

My reservations on this are I think similar to others. The motor just won't produce enough grunt on australian hardwoods. If it had a larger motor maybe....

Regards
Paul