Auto leveling FEL?

RickB · Apr 9, 2004

Stay away from the HSL option on NH 7309 loaders.

DannyD · Apr 9, 2004

Amen to this, experience and the pain of "learning" by picking up loads that were not level is the best teacher. I drove forklifts for 12 years in a paper warehouse. You learn real quick what is level and what is not there.

One thing that comes to mind. Put on the forks, level them with a level.......then somewhere that you can see from the seat, put a mark at the nearest pivot point. Make this mark "level" and when the 2 points are there (or how ever many pivot points you have), you are level.

just a thought

_RaT_ · Apr 9, 2004

Uhm, that solenoid would have been very helpful for me. There where times while lowering the loader I would fight the bucket repositioning itself. On an old Ford tractor I used, there was a simple hydrualic valve that simply bypassed the whole self leveling system. Rat.

AndyMA · Apr 9, 2004

( Stay away from the HSL option on NH 7309 loaders. )

Rick, Thanks. Actually I had no intention of adding it, I just see it in my manual once in a while. I've had the 7309 since 1987 and I'm presently in th eprocess of rebuilding a cylinder for the second time in all these years. I have MSL on my New Holland TN and while it's great for forks, I'm not crazy about it for other uses. I bet with a couple of plazma cut plates and a few pieces of steel you could make most loaders into mechanically self leveling. I've been looking at my LA32 MSL to see if I could make it switchable by changing a few parts. I haven't see the loader on a new TN but from the brochure it appears that MSL is an option and not a separate model. If that's true maybe I can get some ideas there. /forums/images/graemlins/cool.gif

Andy

have_blue · Apr 10, 2004

( But maybe this is open for "invention". A 'level' with gyro that would feed the right information to the hyd. valve box to keep the forks (or bucket) level might be a way to go (as long as expense isn't a limiter).)

That makes me think of a completely independent bucket and leveling mechanism. No additional hydraulics, no plumbing nightmare, and cheap to manufacture. It could be actuated by a power window motor, robust worm and sector gears, and a damped tip switch. When turned on electrically, the bucket would automatically seek for level relative to the tractor's inclination, independent of and regardless of the hydraulics or boom position. It could also have a simple "independent mode", where it always seeks true level.

RickB · Apr 11, 2004

Andy, my first thoughts on your 'convertible' msl would be to remove the rear MSL link from the boom and fabricate a short link that would pin the 3 cornered pivot plate stationary to the loader's boom. Changeover would involve pulling 2 pins on each side, swapping links, and reinstalling the 2 pins per side. Pin mounts for the short, nonMSL link would have to be added to the boom. Interesting thought.

uhmgawa · Apr 11, 2004

( That makes me think of a completely independent bucket and leveling mechanism. No additional hydraulics, no plumbing nightmare, and cheap to manufacture. It could be actuated by a power window motor, robust worm and sector gears, and a damped tip switch. When turned on electrically, the bucket would automatically seek for level relative to the tractor's inclination, independent of and regardless of the hydraulics or boom position. It could also have a simple "independent mode", where it always seeks true level. )

You are competing with Eaton's self-leveling valve for most complex
solution. Although what you describe can be fashioned with parts
scavenged from a Home Depot Zircon level, a cast off cordless screw
driver, and a grab bag of electronics. I'd add a way to disable the servo
but display the incline of the bucket (for manual operation) both
relative to the tractor and absolute level. A front-to-back tractor
incline sensor comes for free here as well.

Then again there is the mechanical linkage a'la the new L48 which I just
managed to get a look at. The mechanism is fairly simple consisting of
a series of differential-sensing pivots tied together from bucket to the
loader's roll valve. Didn't have a camera handy or I would have taken
some pics to reverse-engineer the thing some rainy day. While the
design itself is a bit involved, the implementation is quite low-tech
and I'd predict to be reliable. This is such an inexpensive means to
implement a self-level feature I'm surprised it isn't more common.
Incidenially, there wasn't any apparent means to disable this
mechanism on the L48.

With either above approach you'd need to remove the roll valve spool
centering spring. The self-level linkage connects to the valve spool
via its own compression/extension spring. While removing this isn't
strictly necessary, leaving the original spool center spring in place
will require the self-level spring to overcome the force of the spool
spring. The collective spring resistance would make manual operation
of the valve rather stiff.

keeney · Apr 12, 2004

The other issue here is not so much that you want auto-leveling, but auto-stay-at-the-angle-I-started-at functionality.

When you have something on the forks, often you want a little roll-back to keep it there. Or sometimes, you want less roll-back.

Also, you need to decide if the angle is referenced to the tractor frame or to absolute up/down...

- Rick

uhmgawa · Apr 13, 2004

( Also, you need to decide if the angle is referenced to the tractor frame or to absolute up/down )

Conventional mechanisms maintain the angle relative to the tractor.
However it would be useful in certain scenarios to maintain the angle
relative to absolute level/plumb. Doing so compensates for changes in
pitch of the terrain while the tractor is in transit.