Lifting tractor with FEL and Stabilizers

[john_bud]

It's not cylinder damage that would worry me. It would be structural cracking of the sub-frame, transmission, differential. These tractors are not structurally as robust as a 18,000 industrial TLB. It is much easier to twist the tractor while digging and swinging a load.

Have someone run your tractor with it up in the air as far as you can get it. Have them get a full bucket and with the boom/stick out, swing a loaded bucket quickly all the way to the stops. I haven't watched a BX or B with kubota hoe, but my guess is that you will see it flexing. Repeat that with the tires lightly touching. It won't be flexing near as much.

It would be interesting to have someone do the above and report back. That way we could have some first hand data and not speculation. Any takers?

jb

 

[Berniep]

Well I don't know about the full bucket swing issue but my BX23 really doesn't have the guts to twist the frame a lot. I don't have problems with the tractor moving in use except when I raise it with the backhoe while digging down , then it doesn't matter whether the tractor is fully raised or not it will still bounce me around.

 

[DiezNutz]

Not saying it flexes or it doesn't, but every time this topic comes up, there's inevitably talk about flexing as if it's a bad thing. Not always. I would claim there are as many or more situations where ultimate yield strength of a structural member is exceeded due to it being too rigid/inelastic... concentrates the stress at the mounting points. Tell ya what, any flexing-opposed "stiffs" out there (pun intended)... I've got free tickets for this new airline where all of the planes have completely RIGID WINGS. Any takers? No? Mmm, didn't think so.

I won't lift my BX that way. I leave the bucket in the level position and raise it that way.

Same here, or with the bucket tilted down a bit so that my TB digs in. To me, that picture is asking for trouble.

 

[TalonDancer]

In all the Kubota frame mounted back-hoes I've seen...
The BH sub- frame is bolted to the tubular cross member of the FEL. The back-hoe itself connects the rear tabs of the sub frame forming a box. The tractor is attached to this box via the FEL cross member and where the BH sub-frame is bolted to the rear axle.

When you lift the front end with the FEL, the front part of the tractor rests on the tubular FEL cross member and weight is shift to the rear axle. When you raise the rear end via the BH stabilizers, weight is shifted back onto the FEL and the rear of the tractor hangs from the sub-frame. The rear axle adds rigidity to the sub-frame by spanning it within the "box".

SO... it would seem to me that having your rear wheels touching the ground actually places MORE stress on the tractor. For example, unless the tractor is on perfectly level ground, the higher rear wheel would push up on the sub-frame 'box" more that the lower one -- hence twisting the sub-frame "box" more than if both rear wheels were suspended.

Three legged stools never rock

Talon Dancer

 

[tommu56]

Hi In my bx-23 manual it says to leave 1 rear wheel lightly in contact with ground can't remwmber what it says about front but I try to stab edge into ground and lift front pressure off tires barely

Pat R

And I though I was the only one with bx23 with a Lartharic fel.

when I watched my wifes uncle run a hoe he would plumb the pivot. he was on equipment all his life, when he got done with a trench it looked like it was all ways there smooth sides clean botom and a uniform pile of spoil.

tom

 

[crazyal]

You should always use the rear stabilizers to level (side to side) the tractor and take all the weight off the tires. Leaving one (or both on level ground) just barely touching would be fine. This is a safety issue. Unless you lift the tires off the ground you can't know if you've placed the stabilizer on solid ground. I would rather know before hand then when I swing the boom to the side with a full bucket and skink into what I thought was solid.

When using the backhoe you actually take weight off the front end. When digging your pivoting the weight on the rear stabilizers. Think of a seasaw, add weight to one side (lifting dirt out of the ground) it lightens up the other side. Where you could do damage would be trying to remove roots/ stump/ etc. if you lift the front end off the ground then if the root breaks and front end drops back down on the fel is hard on the equipment.

 

[Dave Shepard]

I use whatever combination of bucket and stabilizers it takes to position the machine as needed. I have no concerns about the tractors ability to handle this use. This job required some of the most technical backhoeing I have ever done. Behind where I am standing is a very steep bank that wraps around a parking area and garage. Few machines would have been able to do this job, and I wouldn't have been able to do it unless I could jack the machine up as needed.

Dave

 

[TalonDancer]

Here is what my new BH90's manual has to say about the use of stabilizers and loader bucket (the attachment is a scan of this section of the BH90 manual).

"Placing the Stabilizers...

1. Lower the stabilizers and remove the weight of the backhoe from the rear wheels. However, one or both rear tires should remain in light contact with the ground. This will give the backhoe the widest possible stance and the lowest center of gravity.
If the rear wheels are raised too high, digging depth will be reduced and undue stress will be exerted on the backhoe frame components.
If the slope is unusually steep,...

2. The loader bucket should be lowered to give the backhoe unit a "tri-pod" stance. With the loader bucket in ground contact, front tire bounce will not be a factor in overall control. When possible, the loader bucket cutting edge should be lowered vertically into the ground surface. This will assist the stabilizers, not allowing the unit to shift, while excavating. However on a slope, the bottom of the bucket should be used, and only the side that contacts uneven terrain. Too much loader down pressure, on a slope, will restrict the unit from being correctly leveled and will place an undue twist though the loader bucket and lift arms."

Talon Dancer