Front end loader tilt angle indicator

A challenge with using the front end loader on my tractor is that when I'm sitting on it I can't see the fork or the bucket when it's down, so I can't tell if it's level.

So I thought I'd build a gadget that shows me what angle the fork is at.

Ironically, this tractor has two auxiliary cylinders in parallel with the bucket tilt cylinder, which, as the loader is raised and lowered, will push more hydraulic fluid in and out of the tilt cylinders to keep the fork or bucket level. Except, the hydraulics have internal leaks and sag, so I can never be sure if the forks are still level.

I drilled a hole through one of the links for the bucket tilting mechanism, put some wire through there, bent it into a loop, and attached some string to that.

The string is from some ribbon that held a packing crate together. It's very strong and, because it's not braided, is not at all stretchy.

I made a little deflector pulley to mount where the loader bends. I attached this to an existing stud that holds the hydraulic lines. I didn't want to drill any holes into the arm because, by the looks of it, it's welded shut on all sides, and I didn't want to add a place where water could get in.

The string goes to a little lever thing that attaches to a pin sticking out on the top. As the forks tilt, this gadget tilts with the fork, so I just have to glance at that to see what angle the fork is at.

This contraption could also be useful to check that the bucket is level. But then I realized, the back of the bucket is not quite perpendicular to the bottom of the bucket, so I'd need to make adjustments to my gadget when switching between the forks and the bucket. Also, I found it difficult to make fine adjustments to it. So I made an improved version out of two parts. The lever part attaches to the wire, and the angle thingy is attached to that in such a way that I can still turn it by friction to set it level for when the fork is level.

The thing is really only critical for showing level when the fork is down - that's the only thing that really matters. But I wanted it to be accurate across the range of motion, so I had to make sure the level indicator tilts at about the same rate as the fork.

Looking at the linkage at the front, the fork is on a linkage 30 cm long, connected to a 48 cm long linkage which has the hydraulic cylinder on it. I drilled into that, at about 20 cm from the pivot.

The link I attached the string to is about 1.5 times longer than the link with the forks on it, so the forks will tilt about 1.5x as much (roughly - four bar linkages such as this are complicated to fully analyze). So for my gadget to deflect about as much as the fork, I needed the string to be attached about 1.5x closer to the pivot than it was on the link.

Also, I should make sure the pivot that the string attaches to on the link is perpendicular to the string when the link on the fork is also perpendicular.

Using it certainly helps, though I still can't see if the forks are lined up with a pallet, or if the bucket is full, so I may experiment with mounting a camera on it somewhere next.

See also:

To my Woodworking website.