Front End Loader Leveling Arms?

[Renze]

I found a picture of my loader, with the most basic (and most true) form of parallel linkage:
You can see the blue and purple lines i drew, connecting the linkage pins of the main boom and the parallel links.

How to do it:

Place your bucket (or pallet forks) on flat ground, then measure the angle of the bucket pin to the tilt cylinder pin: You want this angle also on the small triangular tumbler, which pivots on top of the bend of the loader boom. Then at the loader console, pick a link pin position in which you can move it up and down without colliding. Then again measure the angle and maintain this angle in the second pivot point of the triangular tumbler.

Thats basic parallel linkage.

Most modern loaders dont really have parallel linkage, they cheat a little, and the parallel deviates about 3 degrees over the full range of lift height: It isnt parallel either: This is to give more bucket breakout force at ground level (with slower bucket tilt) and quicker dump cycles when fully lifted (and less force, where you dont need it anyways)

figuring that out isnt worth the hassle if you plan on building only 1 loader... you'll be sketching and connecting points with circles for a week or 2, to increase your dump cycles by less than seconds......

My basic parallel linkage works very fine. I used the half-done loader for some months before i added the parallel linkage, so i know the difference: I dont want to load bales without it !!!

 

[mwb]

I would make it self leveling; I have thought about modifying my loader to have this but will probably wait until it is a little older The design of this is relatively easy, do some research on "4 bar linkage".

If you would like a real engineering challenge then try making one like this one Landini Canada Inc Bradford Ontario Landini Tractors
Can't imagine how many greese fittings that thing must have

 

[Renze]

If you would like a real engineering challenge then try making one like this one Landini Canada Inc Bradford Ontario Landini Tractors
Can't imagine how many greese fittings that thing must have

I have attached a picture with a scheme of the geometry involved. The green arms stretch out the front section, and the yellow arms cause the bucket to follow.
The only thing that impresses me is the number of grease zerks: The design isnt really as complicated as it seems, and a similar concept from Mailleux France proved that it wont last: A double pivoting main boom will be very prone to torsion flex and fatigue, even if high tensile fine grain steel types are used. (All modern loaders use Domex or Naxtra high tensile steel these days)

 

[rback33]

How are you relieving pressure in the system? Or are you? Personally, I am not a fan of MSL loaders. The loss of roll back angle is not worth it. Hydraulic self-level is the only way to go. Someone posted the link to the video on our website in the Mahindra forum. The link is to Youtube where our marketing people put it, but it can be found on our website as well.

To each his own. I can't justify the time to engineer it from scratch, but if you can then power to ya.

 

[Renze]

How are you relieving pressure in the system? Or are you? Personally, I am not a fan of MSL loaders. The loss of roll back angle is not worth it. Hydraulic self-level is the only way to go.

I'm not relieving pressure in the system... there is a built in safety device that limits the pressure in the tipping cylinders, and it is mechanically strong enough to withstand the lockup in most extreme positions.

Within normal loader operating, it hardly meets its most extreme positions. the only drawback of my current setup is that i cant tip out far enough at ground level, to dump to grade. I will fix that by welding an extension to the tipping cylinders. (i have to weld a new pivot end with bushings to it anyways)
Oh, and my Euro standard quick attach doesnt allow enough tipping at full height either.. This is a small design flaw that has to do with the toolcarrier alone and would also have occurred without the self levelling.

About which type of hydraulic self levelling are you talking ?? The type with an extra pair of hydraulic cylinders near the main mounting brackets at the tractor end of the loader, or the type with a hydraulic flow divider valve ?? The latter is just a poor substitute, IMHO because its angles change with the viscosity (temperature) of the oil, and because of the geometry of the loader itself, the tipping cylinders dont need the same oil flow split over the full range of lift height....

 

[rback33]

About which type of hydraulic self levelling are you talking ?? The type with an extra pair of hydraulic cylinders near the main mounting brackets at the tractor end of the loader, or the type with a hydraulic flow divider valve ?? The latter is just a poor substitute, IMHO because its angles change with the viscosity (temperature) of the oil, and because of the geometry of the loader itself, the tipping cylinders dont need the same oil flow split over the full range of lift height....

The flow diverter valve... Our hydraulic self-level feature is tops in the industry, bar none. Oil temps have no impact on our system. The only thing we have to combat is cavitation, but that is controlled partly by the spool valves that are compatible with our kit.

 

[R W]

You don't want to mess with building your own MSL loader. I don't see anyway you could do that unless you are already a loader engineer.

I don't think you would need an engineering degree to build an MSL loader,
have a close look at a factory built one and work from there.

 

[rback33]

I don't think you would need an engineering degree to build an MSL loader,
have a close look at a factory built one and work from there.

This is true. That does not make it level up and down perfectly though, or maximum dump angle and roll back angle. Nor does it relieve the pressure in the system when it lock out unless you have a relief block plumbed properly with the correct relief settings. Can it be done and will it work? Certainly. No question about that. Will it be perfect? No. Will it level perfectly up and down? Maybe, but not without quite a few versions probably. Maybe I am too picky. If I was doing it, I would not be happy with "kinda level" or "level most of the time."

If you had ever seen or heard what happens when the self level mechanism locks up with no relief in the system you would be more worried about that aspect too. Exploding loaders are not cool.

 

[rhamer]

Thanks to everybody for your replies, I have got some great information.

The challenge I faced was deciding whether leveling arms were worth it in practice, not whether I could build them or not.

I realise that this forum is not limited to engineers, so I should have mentioned up front that the engineering is not a problem to me.

Given the positive feedback for some type of leveling system, and the fact that a mechanical one is easy for me to build, I think it is worth the effort.

The real challenge for me in this project is the 4in1 bucket. Yes I could buy one, and I could also just buy a loader as well, but where is the fun in that

I'm sure I'll make mistakes, but fortunately I can cut and grind as well as I can weld

Cheers

Rohan

 

[rhamer]

This is true. That does not make it level up and down perfectly though, or maximum dump angle and roll back angle. Nor does it relieve the pressure in the system when it lock out unless you have a relief block plumbed properly with the correct relief settings. Can it be done and will it work? Certainly. No question about that. Will it be perfect? No. Will it level perfectly up and down? Maybe, but not without quite a few versions probably. Maybe I am too picky. If I was doing it, I would not be happy with "kinda level" or "level most of the time."

If you had ever seen or heard what happens when the self level mechanism locks up with no relief in the system you would be more worried about that aspect too. Exploding loaders are not cool.

Can you elaborate on how this "lock up" can occur, I can't understand given all you are really doing is moving the rear anchor points for the curl cylinders as the loader raises?

Cheers

Rohan