Logsplitter 2.0

[rswyan]

A couple of the 4-way wedge, with it flipped both ways.

Low:

High:

Could probably stand to have a little more taper out on the vertical knife edge.

 

[rswyan]

These were the two logs I tried last night.

The one on the left (that I couldn't lift) is what I think is ash ... notice how the cracks along it's length are straight, as opposed to the smaller sycamore on the right where the cracks spiral:

The (longest) diameter dimensions were 31" for the ash, 19" for the sycamore.

 

[LD1]

I think you need to add a piece of the thinner flat material in front of your wedge. To help it get started before it widens. Like a few inches of knife edge to penetrate first.....then the main show.

Working on the lift math right now

 

[LD1]

Something has to be wrong with the measurement.

A, B, C all form a triangle. Those are what I need to find the angle of the cylinder (line BC) in relationship to AC to calculate the force of a cylinder on an angle.

You have line AC being 25", which is greater than the sum of the other two legs of the triangle.

 

[rswyan]

Something has to be wrong with the measurement.

LOL ... mebbe not ... :laughing:

Remember I mentioned that I had a clearance issue between the log lift frame and the body of the larger cylinder, and redoing the attachment point probably reduced the amount of the amount of initial angle on the cylinder ?

It may be that the angle went negative - past 6 o'clock back towards 7 (using the pic I posted of the log lift in side view for reference) .... in that case, the lift would want to go down rather than up.

Look at where the weld broke on the frame ... if I had to guess, for it to break in that manner, where it did, is more likely if the lift is being pushed down rather than up.

A, B, C all form a triangle. Those are what I need to find the angle of the cylinder (line BC) in relationship to AC to calculate the force of a cylinder on an angle.

Got it.

You have line AC being 25", which is greater than the sum of the other two legs of the triangle.

So basically, the longest side should be be equal to the sum of the other two sides of the triangle then ?

I'll recheck the measurements ...

 

[LD1]

So basically, the longest side should be be equal to the sum of the other two sides of the triangle then ?

I'll recheck the measurements ...

No. If the longest equals the sum of the other two you dont have a triangle at all. Rather when drawn in 2d.....you have a straight line.

The two short sides HAS to be greater than the long side....otherwise, no triangle.

And you clearly have a triangle in the design. Just a wrong measurement somewhere. Did you actually measure the cylinder? And not just use the retracted length specs? perhaps the cylinder cannot retract all the way with your design and when all the way lowered, is actually extended a few inches?

 

[rswyan]

No. If the longest equals the sum of the other two you dont have a triangle at all. Rather when drawn in 2d.....you have a straight line.

The two short sides HAS to be greater than the long side....otherwise, no triangle.

Ahh ... got it ... sorta ... :confused2:

And you clearly have a triangle in the design. Just a wrong measurement somewhere. Did you actually measure the cylinder?

No.

And not just use the retracted length specs?

That's exactly what I did ... use the retracted length spec :ashamed:

... perhaps the cylinder cannot retract all the way with your design and when all the way lowered, is actually extended a few inches?

Correct ... although not by a few inches ...

The actual measurement for BC at present is 19 3/16" .... but keep in mind that's with a broken weld which adds a little length due to the gap where the weld broke.

I'd say that if it were unbroken the measurement is probably in the neighborhood of 19 1/16".

I threw a Dasco magnetic angle finder on the cylinder just for giggles and at least it does have a slight angle (2 or 3 degrees mebbe) in what appears to be the correct direction.

 

[rswyan]

Probably should figure on dimension AC being slightly shorter as well ... due to the weld break.

Mebbe 24 3/4" ....

Using 5.875" for AB, 19.0625" for BC, and 24.75" for AC, I'm coming up with 3.885 degrees for an initial angle ... with about 1197 pounds of force being generated for a 3" cylinder @ 2500 psi.

Sound about right ?

 

[LD1]

That be the problem.

A tad over 19" plus a tad under 6" is about 25". The length of the AC side. You are putting alot of force into doing not alot of work. Need more angle difference.

A cylinder on a 2 degree angle only has 3.5% of its force available for the lift. Half that at 1 degree.

So at 2 degrees and 2000psi, you can lift 475# total. Take the weight of the lift of....and you have very little capacity.

And that means the other 13000 pounds of force from the cylinder is trying to push itself apart, as it did

 

[bigmog]

just caught the end of this story, to get any decent use out of your splitter, get the biggest engine you can, the 11 hp would be a start, your lifting arm, remember the friction you need to overcome on the start of the lift, if you just rely on pins and holes, this can be very high, even a well greased bushing will make a big difference, and as for the weld breaking, from your picture it looks like a bad weld, no penetration on the solid, grind it out re-weld it and stick a fillet on for good measure, keep on building