Self leveling loader (again)

[Reg]

OK, given that it is a misnomer anyway, I still want to convert/adapt my front end loader so that the bucket maintains a (more or less) constant angle to the tractor as the loader is raised/lowered.

My bucket cylinders are on top of the arms and I have seen JD and Kioti self levelers that have triangular brackets atop of the loader arms with rods running back to the lift arm base.
It is just a neat little parallelogram of linkages and with all the Imagineering talent here I just KNOW that someone else has done this and could lead me through the design/development steps.
Fabrication is another matter, I will either sign up for a semester at the local voc tech next month, or have a local weld/fab shop build it for me.
Mostly for the pallet forks, but "nice to have" for snow removal and general bucket work too.

 

[Renze]

http://www.tractorbynet.com/forums/build-yourself/85834-home-building-frontloader.html

This is my loader, in 2005.
My father said i was nuts, investing so much time in a front loader that wouldnt see more use than one week per year... 2 weeks ago i bent a self levelling pushrod (a weld broke of the bracket, the other bracket plate bent with the rod) and they are getting all upset about the loader not being available for 2 days...

 

[Reg]

Thanks, that is the sort of thing I have in mind.
I just need to make LOTS of measurements, particularly the spacing between existing pivot points that I will keep.
Then "DO the geometry", make cardboard or plywood templates/mock-ups to see if all the new triangle and proposed linkages will work together to give "good enough" self leveling.

Good point about starting with the pallet forks ON and level on the ground as the initial reference point.
That determines the nominal length of the bucket cylinder when level and on the ground, in turn that determines the forward parallelogram......yeah, I can probably get there from there.
I will probably do that first, then the same with the bucket just to see if there is a difference.
If there is I will favor the pallet forks (maybe 80% if compromise is indicated).
The rear parallelogram next and... ta dahh, I probably have the spec for the (geometry of the) triangular brackets.

 

[Renze]

I made the layout of what i knew then, looking at other loaders:
I had hooks on my bucket before i made the parallelograms and later i made a bale spike and pallet forks, so my bucket was the reference point for the triangles. The bucket maintains 100% parallel with a flat bucket lip, however thats where i went wrong: When it is tipped in 45 degrees, it will dump out to 25 degrees during lifting, because it is based on a horizontal bucket, not a 45 degrees tipped back bucket.

At the payloader plant i work these days as a designer, my predecessors made the linkage lengths so that a bucket maintains parallel when its 45 degrees tipped back (no spillage lifting a closed bucket all the way up) and the pallet forks has its quick connect so that the connector is tipped 45 degrees back when the forks are horizontal.

Now the problem with farm loaders is that their booms have about a 50 to 60 degree angle in them, so the front wheels can steer underneath. If i modified my parallel triangles so that it would level a closed (45 degrees tilted back) bucket, it is getting near a dead angle where the cylinders are pulling the quick attach against the frame, with little leverage.
John Deere on some loaders, has a triangle with an adjustable hole, so you can adjust the kinematics for bucket or forks.

Another thing: I extended the bucket cylinders a few weeks ago (i needed to pound out those pins anyways to make a new pushrod) because i didnt have enough dump angle at ground level, because of the triangles which mount higher than the original mounts.

I still have a couple of inches to spare on my dump cylinders, so i am thinking of modifying the entire front part of the self levelling, making the cylinder attachment points higher on the triangles, the quick attach and extend the tumble arms on the front.
When i utilise the full stroke of my dump cylinders, i can get the same tipback and dump angles with more leverage on the bucket: If that gives me enough torque to hold a full pallet of bricks even with the quick attach tipped back, i might modify the triangles, to get my self levelling to work with a 45 degrees tipped back bucket, and modify the pallet forks, bale clamp, bale fork to the new configuration...


So keeping the bucket floor parallel should not be your goal: You need to keep it at a 45 degree rollback angle to prevent spill. But just figure if you keep enough torque to hold anything on the pallet forks when the quick attach leans that far back.

 

[KennyV]

Renze ... nice job on the loader, You so good work.
also a fan of tulips in the garden... KennyV

 

[Reg]

OK, thanks for the full bucket tip(pun).
I will TRY FOR two sets of holes in the triangles, if that can't work out I will probably go in favor of the pallet forks and CONCENTRATE when lifting a full bucket high - which is not something I do often,,,, except for snow and I have learned to NOT dump that on the front of the tractor and ME - once, it only took ONCE !
(-:

 

[GE222]

Another option.
On a Case 580CK construction tractor ( from the 70's), is a 5th hydraulic ram. It is located close to the loader arm pivot point and is connected between the loader arm and the loader frame. As the loader arms are raised, it offsets the hydraulic fluid to the bucket cylinders providing a hydraulic bucket leveling feature.

It is much simpler than the linkages for mechanical leveling; however, creating one from scratch will require careful calculations for both the position as well as the 5th cylinder flow rate versus position.

First calculate the volume needed from one or both bucket cylinders (depends on the tractor) that is required to keep the bucket level from the lowered, start position to the raised position. Then select a ram that has a greater volume than what is required. The chosen ran must have enough stroke to accommodate loader arm movement. Using the volume from the bucket cylinder(s), calculate the stoke of the 5th cylinder. The calculated stoke will determine the mounting position of the 5th cylinder.

The 5th ram I believe was Tee'd into the bucket cylinder hydraulic circuit.

I am doing this from memory, so if anyone else has seen this application, speak up!

There may have been other tractors over the years that had this feature.

 

[Renze]

Yes, hydraulic self levelling was standard on the Humpolec loaders from 1975
French brands sell it, John Deere has HSL and Allied had it for a long time too.

 

[Reg]

Interesting, but I seem to remember reading somewhere else that (some) hydraulic self leveling systems work only on raise, not on lower.

Interesting too that Humpolec loaders have/had it as standard back in the mid 70's.
It is a Humpolec loader that I am considering this for and PART of what stimulated the idea is the extra/other set of holes at the top of the lift arms - suggesting that the arms are also used for a different configuration, e.g. maybe a self leveling version.

The large frame Branson, Century, Kukje 38, 42, 47 HP tractors that went under the Zetor name for a short while, imported by American Jawa.
If there is any sort of add-on "kit" for conversion to self leveling - SURE I am interested (-:

Parts, parts, nuts and bolts, I can usually handle THAT level of mechanical work.