Big Tree Trunk Splitter

[Sawchip]

14 minutes ago, Billhook said:

Drawbar pull in the Nebraska test was 26,286 lbs or 11.73 tons

Drawbar hp was 103

 

The basic tractor weighs 14.22 tons dry

to that has to be added the dozer blade and C frame                                                         2.5 tons.

                                          the hydraulic system and two large rams                                   1.0 ton

                                         the heavy underbody protection and grill  must be                     0.5 ton

                                         The Hyster D7N winch and cable      2750 lbs plus cable about  1.5 tons

 

Must be approaching 20 tons with fuel oil and water.

 

But I cannot see how the pull test equates to the push test where you have all that weight and power concentrated on a small area.  The drawbar test I would have thought is more about power and traction

The PSI with the dozer pushing must be huge.

 

 

I suppose..... If you had a run up to the log to be split then I can see how the moving mass of the D7 would come into play rather than just the drawbar pull / traction from a static start... You would have a D7 hammer of sorts if you started before the log and you would get much more force to start with until that force reduces to what the D7 can then maintain carrying on pushing. Your vid shows you edging forward under control to start the splitting so I guess the D7's pull/pushing traction force of near 12 ton is enough to do the job. I think you would have to be down hill to add to the force using some of the D7's weight .  

 

 

 

[Billhook]

5 minutes ago, Sawchip said:

I suppose..... If you had a run up to the log to be split then I can see how the moving mass of the D7 would come into play rather than just the drawbar pull / traction from a static start... You would have a D7 hammer of sorts if you started before the log and you would get much more force to start with until that force reduces to what the D7 can then maintain carrying on pushing. Your vid shows you edging forward under control to start the splitting so I guess the D7's pull/pushing traction force of near 12 ton is enough to do the job. I think you would have to be down hill to add to the force using some of the D7's weight .  

 

 

 

The Nebraska test would have been on full throttle in first gear,  I was only on quarter throttle in the video

[Sawchip]

16 minutes ago, Billhook said:

The Nebraska test would have been on full throttle in first gear,  I was only on quarter throttle in the video

I take it you think that the D7 must be generating more tonnage to be able to do what it did ?

 

[Billhook]

31 minutes ago, Sawchip said:

I take it you think that the D7 must be generating more tonnage to be able to do what it did ?

 

I would agree with all your theories , but I was very surprised to see how easily the D7 performed compared to the six or seven ton Matbro. which has a very powerful telescopic boom, and even when I rammed it into the trunk nothing happened.

I would have thought that the Matbro would have generated several tons of ram power on paper but it came to nothing in the actual test.

[Sawchip]

27 minutes ago, Billhook said:

I would agree with all your theories , but I was very surprised to see how easily the D7 performed compared to the six or seven ton Matbro. which has a very powerful telescopic boom, and even when I rammed it into the trunk nothing happened.

I would have thought that the Matbro would have generated several tons of ram power on paper but it came to nothing in the actual test.

I would think with a smaller chunk the Matbro might start opening up the end.  The thing Im keeping in mind is, once the blade in the ground or a wedge gets into the end grain the amount of force needed is a bit less as the wedge starts to do its job .Mind you.... Across the grain on a log brings things to a different end with manny a splitter.

Tell you what though... the D7 gives you speed at the same time as force . Easy to make a hi tonnage splitter thats slow moving under load ...but a fast cycle hi tonnage one is another thing. 

[Billhook]

Had another go earlier today to just try and re-split the larger piece from the first attempt.   Because I could not see what was happening and the mud did not help and I stupidly did not wait for someone to watch for me, the piece of timber slid sideways and pushed on the right side of the horizontal knife.  This knife is held in position by two half inch thick pieces of  three inch wide steel and the force of the dozer bent them slightly, which demonstrates the power of the forces involved

[Cosmiccrofter]

Would it not be easier to reverse into it, for visibility, with some sort of plate attached to the back of the beast?

[Billhook]

On 20/12/2019 at 16:00, Cosmiccrofter said:

Would it not be easier to reverse into it, for visibility, with some sort of plate attached to the back of the beast?

Winch limits both visibility and fitting a plate, also the whole machine is designed for pushing and I rather think reverse gear ratio is higher than forward ratio.

[Sawchip]

On 19/12/2019 at 22:03, Billhook said:

Had another go earlier today to just try and re-split the larger piece from the first attempt.   Because I could not see what was happening and the mud did not help and I stupidly did not wait for someone to watch for me, the piece of timber slid sideways and pushed on the right side of the horizontal knife.  This knife is held in position by two half inch thick pieces of  three inch wide steel and the force of the dozer bent them slightly, which demonstrates the power of the forces involved

Im just being nosy now...you say your D7 is 128 hp, would that make it a 4 cyl and be a D7D ?

 Could you indulge my curiosity with a pic or two of it if its not a bother? 

[Billhook]

3 hours ago, Sawchip said:

Im just being nosy now...you say your D7 is 128 hp, would that make it a 4 cyl and be a D7D ?

 Could you indulge my curiosity with a pic or two of it if its not a bother? 

Dangerous territory Sawchip!

 

Have you not heard about the father who took his little daughter to the zoo where she became fascinated with the penguins .   So for Christmas he bought her a book on penguins and after she had read it asked her if she had enjoyed it

” it was ok dad, but it told me more about penguins than I wanted to know!”

 

of course there is my Avatar with the two wonderful Airedale’s helping me level the chalk roads on the farm.

 

So a long Christmas shaggy Caterpillar story for you

 

It all started back in the 1960s when my father bought me a book of science fiction short stories .  One was called Killdozer by Theodore Sturgeon about a D7 which became overcome by an alien force which entered the very atoms of the machine and then proceeded to try and kill all the civil engineering crew on this island in the Pacific where the Americans were making a runway

It was made into a film of the same name which was rather poor and featured a D9 not a D7

When the boss of the civil engineering team was asking the team who drove what, he came to a Mexican who said he drove Daisy Etta.  The boss said that was cool because if a man called a machine a pet name then he was likely to care for it.

“No, no “said the Mexican, “I drive de siete” which is of course Spanish for D7, but the original name stuck in the book, though of course they could not use it for the film.

 

I bought it in 2000, it had been sitting on an airfield for many years and the story was that the head was cracked as it spewed out water.  After buying it I discovered that the reason it was losing water was because someone had blocked up the pressure relief valve with silicone

There was no starting engine, just a not very well engineered electric starter which was useless.  I asked father and son team Robert and Allan Wilson to find one and they put me right from the start

I had already bought some high quality bolts to fix the new donkey on the block but they refused to use them as they were not Caterpillar bolts

They then showed me the difference.  The Caterpillar heads were about one and a half times deeper but more than that every bit of steel on the D7 has to meet the Caterpillar standard which is why these machines last so long

 

It is a 1956 D7 C. 17A with hydraulics as opposed to cable.

The blade had three positions which are easily adjusted by hand as the blade of perfectly balanced 

There is a two speed gearbox with the donkey/ pony starting engine which is a twin cylinder petrol of about 1400 cc which shares its water with the main 13.5 litre four cylinder diesel.

This engine produces maximum power at about 1000 rpm and it has a decompression lever above the high/ low gearbox lever on the donkey

The idea is that in Artic conditions, when the oil is cold and thick, you can run the donkey with the main engine decompressed until the oil pressure is normal and then temperature is up.  The exhaust of the donkey heats the inlet manifold which is clever.

The donkey is strong enough to lift the blade and move the crawler on level ground

The Hyster winch has about a thirty to pull

In the picture with the levers, the far right is the blade up and down, then the forward reverse, the the five gears.

Two hydraulic assisted steering clutches with brake pedals below for turning on a sixpence

The main throttle in the centre back to increase forward to idle.

The main hand clutch lever then the two winch levers, the nearest is the brake and the other the forward/ neutral/ reverse.

Here is a video of spooling a new winch cable on the drum using the Matbro as a dead weight to keep it tight.

 

Warned you it might be more than you wanted to know!