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Discussion Starter · #1 · (Edited)
Here's the story, I've got 8" stroke cylinders and am having a little trouble figuring out how to have enough curl back when lowered and still have enough forward curl to dump at full lift height.

I'm guessing I'm going to need to make an "eccentric" type of linkage to achieve this since 8" stroke doesn't seem to be enough to do both on cylinder movement alone.

Here's a bit of a mock up I'm doing to get a better visual of what I'm going to build.

Lowered:

2507236


I've got a decent amount of curl back to travel with the bucket low. That's at full lower, so a little raise to travel will give more tilt back to help not drop material.

Full lift:

2507237


The tig rod you can just see sticking out the end of the carboard buck represents the cylinder travel of 8". Obviously, there's no way I'm going to get enough tilt to dump at full lift like this.

An obvious answer would be to use a longer cylinder, but I don't have that option (finances) and a longer cylinder means longer retracted lebgth, which will cause problems at full lower and I won't get enough curl back.

Can anyone suggest a geometry or eccentric type linkage that would get me to where I need to be?

Thanks.
 

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Here's the story, I've got 8" stroke cylinders and am having a little trouble figuring out how to have enough curl back when lowered and still have enough forward curl to dump at full lift height.

I'm guessing I'm going to need to make an "eccentric" type of linkage to achieve this since 8" stroke doesn't seem to be enough to do both on cylinder movement alone.

Here's a bit of a mock up I'm doing to get a better visual of what I'm going to build.

Lowered:

View attachment 2507236

I've got a decent amount of curl back to travel with the bucket low. That's at full lower, so a little raise to travel will give more tilt back to help not drop material.

Full lift:

View attachment 2507237

The tig rod you can just see sticking out the end of the carboard buck represents the cylinder travel of 8". Obviously, there's no way I'm going to get enough tilt to dump at full lift like this.

An obvious answer would be to use a longer cylinder, but I don't have that option (finances) and a longer cylinder means longer retracted lebgth, which will cause problems at full lower and I won't get enough curl back.

Can anyone suggest a geometry or eccentric type linkage that would get me to where I need to be?

Thanks.
I flunked geometry but have you though of using a clamshell type bucket?
 

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I am no geometry wiz with length verses lost power/strength with an eccentric. BUT I would say if you use a "lever" or eccentric to give the bucket more movement you lose strength in your curl weight ability. You could off set it a bit so it works like a bicycle chain where one side is longer from the pivot point but I still think you will lose the power to curl. "it's not to scale for sure"

I hope this helps a little it's hard to explain in a pic, but with the short side on the piston you get more moving length on the long side. Moving the mount point on the bucket will change things also. If you were to do this you would need to reverse your hoses to the control as it will reverse the way the piston works the bucket. And of course you could put the piston on the top part of the lever and the bucket rod on the bottom if binding is a problem.

Bottom line is you need longer cylinders or change your main arm geometry to accommodate what you are looking for. :(
 

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I know what you're up against with the bucket curl. I built my own J.B. sr. style loader for my 300. Lots of trial and error. One interesting design is the Case 646. Lots of videos on YouTube.
 

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Easy! Move the cylinder base end mount down the arm closer to the bucket.

With a single pivot, about the best that you can expect is a 90° rotation of the bucket. With a compound linkage such as for a back hoe bucket, 180° of bucket rotation is possible, but that is a lot of work, either trial and error, or drawing multiple linkages and two pivot points to scale.

FEL geometry is all triangles.The corners of the triangle are defined as the pivot pins involved. In the case of the bucket, those are the cylinder pins and the arm to bucket pin. The location on the arm of the cylinder to arm pin in relation to the bucket to arm pin determines where the dump angle occurs, and the cylinder to bucket pin in relation to the bucket to arm pin determines how much rotation can be achieved.

Note that cylinder to arm clearance when retracted and rod to arm clearance when extended is critical for maximum available bucket rotation. Adjusting the cylinder to arm pin to be further away from the arm (above) may be necessary to provide the necessary clearance. What you do not want to end up with is a straight line through all three pins when the cylinder is fully retracted or fully extended. You also do not want the cylinder body or the rod to make contact with the arm.

There are three variables that you can play with to get what you want, two that I've already mentioned, and the third is the location of the bucket to cylinder pin which can be moved forward or backwards to fine tune where in the bucket rotation the bucket will be horizontal. Moving any one pin, even a fraction of an inch, will affect how the overall geometry works. Always check to see what else happened.

It's doable with cylinders that short, but available force at the cutting edge for rotation will be diminished. I hope that you have 2" bore bucket cylinders to offset the shortage of stroke.

Take your time reading this. There is a lot of information packed into relatively few words and it may take more than one reading to sort it all out.

I'll give you a starting point. All dimensions are to pin centers.

Cylinder base pin - 1.5" above the top of the arm, and 13.5" from the arm to bucket pin.

Cylinder rod pin - 6" from the bucket to arm pin.

Adjust from there to find what you need.

Good luck.
 

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Discussion Starter · #6 · (Edited)
Easy! Move the cylinder base end mount down the arm closer to the bucket.

With a single pivot, about the best that you can expect is a 90° rotation of the bucket. With a compound linkage such as for a back hoe bucket, 180° of bucket rotation is possible, but that is a lot of work, either trial and error, or drawing multiple linkages and two pivot points to scale.

FEL geometry is all triangles.The corners of the triangle are defined as the pivot pins involved. In the case of the bucket, those are the cylinder pins and the arm to bucket pin. The location on the arm of the cylinder to arm pin in relation to the bucket to arm pin determines where the dump angle occurs, and the cylinder to bucket pin in relation to the bucket to arm pin determines how much rotation can be achieved.

Note that cylinder to arm clearance when retracted and rod to arm clearance when extended is critical for maximum available bucket rotation. Adjusting the cylinder to arm pin to be further away from the arm (above) may be necessary to provide the necessary clearance. What you do not want to end up with is a straight line through all three pins when the cylinder is fully retracted or fully extended. You also do not want the cylinder body or the rod to make contact with the arm.

There are three variables that you can play with to get what you want, two that I've already mentioned, and the third is the location of the bucket to cylinder pin which can be moved forward or backwards to fine tune where in the bucket rotation the bucket will be horizontal. Moving any one pin, even a fraction of an inch, will affect how the overall geometry works. Always check to see what else happened.

It's doable with cylinders that short, but available force at the cutting edge for rotation will be diminished. I hope that you have 2" bore bucket cylinders to offset the shortage of stroke.

Take your time reading this. There is a lot of information packed into relatively few words and it may take more than one reading to sort it all out.

I'll give you a starting point. All dimensions are to pin centers.

Cylinder base pin - 1.5" above the top of the arm, and 13.5" from the arm to bucket pin.

Cylinder rod pin - 6" from the bucket to arm pin.

Adjust from there to find what you need.

Good luck.
thanks. I tried cylinder to the bucket but couldn’t get enough rotation to get an adequate (at least to my eye) dump angle. I’ll try it again, but I think my stroke is just too short.

I’ve almost got it (I think) with a linkage:

2507319


2507320


pardon the thumb, lights were washing out the camera.

that only uses 7” of the 8” stroke, but I’m not completely happy with the angles in the lower and curl back position, nor with having an extra inch of travel unused that might bend/brake something if I’m not paying attention and it tries to go too far.

one of the key breakthroughs to getting it to work was the dog-leg link.

it was a major “B” to get the rotation needed and not have the links go completely straight. Definitely don’t want a situ where they can go over-center. The lower position is still pretty close to that and I’ll see if I can get a little more angle on it. But it’s pretty tight on what fits, what hits and what works. This is so small, it seems even a mm or two throws it all completely out of whack.

I think I might be able to get to final geometry with a little more fooling around.

cylinders are 2.5” diameter. Might move a little slowly, but I’ll accept that over not having enough “grunt”.

bucket level at full lower is just about 2” below the front tires, which should let it dig half decently well. Its only ever really going to move top soil around the yard anyways.

Ordered my steel today. Holy crap have the prices gone through the roof! Its at least twice as much as I would have paid before this pandemic and the trade issues….
 

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A big part of your problem is the angle of the front section of the arms. It's difficult to get leverage without having some space between the arm and the bucket. Note the shallower angle on mine, and how much further in front of the tire the end of the arm is located. While having the bucket close to the front axle is a good thing, it is also possible to be too close.

How long is the arm from post pin to bucket pin. The one on this tractor with a 52" wheelbase is 55.5".

2507378
 

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Discussion Starter · #9 ·
A big part of your problem is the angle of the front section of the arms. It's difficult to get leverage without having some space between the arm and the bucket. Note the shallower angle on mine, and how much further in front of the tire the end of the arm is located. While having the bucket close to the front axle is a good thing, it is also possible to be too close.

How long is the arm from post pin to bucket pin. The one on this tractor with a 52" wheelbase is 55.5".

View attachment 2507378
I seem to have missed that in my design. A bit of tweeking should be able to get me there though. I might kick the forward part of the arms out a bit and see what that does for me…
 

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Discussion Starter · #10 · (Edited)
Well, for better or for worse, here it is.

Full lift and full dump:

2507671


Thats just a touch over 6’ to the arm, about a foot less at what will be the bucket cutting edge.

full lift and full curl back:

2507672


Full lower and full curl back (note theres no reason for full lower and full curl unless while pushing bucket into pile) :

2507673


Full lower and bucket level:

2507674


you will note that the bucket is about 1-1.25” inches below ground level (represented by 2x4 pressed up against both front and rear tires) for digging.

thats about as good as I can get it, or at least as good as to where my patience has worn out. Two days fighting with cardboard, screws, 2x4’s and geometry has pushed me to the “good enuff” point.

It’s getting built from this point forward, I’ve had enough of the tweaking and cursing.

Getting the geometry properly replicated in steel is the next hurdle to clear…
 

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Discussion Starter · #11 ·
Changed up to something like this:

2511352


The linkages were just a bit too fiddle-y for my liking. Much happier with a direct mount.

The bucket gets a 25 degree forward lean to facilitate the new linkage:

2511353


And, started on the loader arms:

2511354


Still massaging things like angles and positioning, but getting there!
 
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