FEL Geometry

rhamer · Dec 25, 2008

I am looking for some advice on dump and rollback angles for my home made loader.

After searching around a bit it seems that an average dump angle id 45deg and rollback about 27 deg

Firstly does this sound correct?

Also is it correct that the rollback angle is measured with the bucket flat on the ground i.e how far the front edge will lift up?

And is the dump angle measured with the bucket at maximum height and with the bottom parallel with the ground i.e how much the front edge dips down?

Does anybody know the actual specs of their FEL or have a link to a site that dies.

Cheers

Rohan

MJPetersen · Dec 26, 2008

Looks to me that you have it prety well figured out. Those numbers seem about right to me.

Mike

Renze · Dec 27, 2008

My loader tips about 90 degree in highest lift position, and i really need that to get rid of some sticky black muck in the bucket.

Commercial front loaders i work with at work, have a 45 degree tip out at highest lift position, and a 45 to 50 degree rollback at carrying position (a foot off the ground)

rhamer · Dec 27, 2008

I am a little worried that 45deg won't be enough, but it is a 4 in 1 bucket, and if anything sticks a bit, I should be able to get it out by opening the bucket.

At least that's what I hope.

One thing I am interested in is the purpose of the second pivot some loaders have between the end of the curl cylinder and the bucket, with a little tie rod in between. I'm asuming this alows a bit more dump angle as it stops the cylinder from hitting the main arm before reaching the end of it's travel. Does that sound right? or is it for something completely different?

Cheers

Rohan

Renze · Dec 27, 2008

rhamer said:
One thing I am interested in is the purpose of the second pivot some loaders have between the end of the curl cylinder and the bucket, with a little tie rod in between. I'm asuming this alows a bit more dump angle as it stops the cylinder from hitting the main arm before reaching the end of it's travel. Does that sound right? or is it for something completely different?

It is to generate an even tip and rollback torque over the entire angle range.
standard scooping loaders have Z-kinematics, which will have high breakout force (the Z-linkage inverts the direction, meaning that breakout is done with the bottom side of the piston, not with the smaller surfaced rod side) The other advantage is the fast dump cycle because the Z-bar "falls" into a dead spot when the bucket is fully dumped, increasing the dump speed but taking away all torque. If you poured concrete in the bucket (so it doesnt drop out when dumping) the Z-kinematics equipped loader will probably not even be able to roll back the bucket to scoop position.
CAT also sell "toolcarrier" loaders with parallel kinematics (as used on most ag front loaders) next to their scooping machines with Z-kinematics.

On the loaders we build, the torque on the bucket edge when fully tipped out, is enough to push the loader out of sticky situations in allmost any condition. This is a big advantage in the soft Dutch soils.
It also greatly improves the ability to use boom lifts. Lately we sold a loader with a 22 meter 7 stage telescopic boom, which is a popular alternative for a telescopic crane, because the loader can drive with load, and be quicker at the jobsite for small jobs lifting a tray of bricks to the next stage. Allmost 70% of our biggest loaders are used to carry concrete hoppers, pallet forks or hoist booms. Having the extra torque when putting the boom horizontal by the bucket tilt cylinders , and the true parallel action with very little deviation, are not just advantages, but simply indispensible.