OK, How About B7500 vs. B2410?

[Anonymous Poster]

Re: BX Boulder Mover

TresCrows...

You sure are right about that leverage thing on bucket curl, the backhoe has the same thing, I've not exactly figured out where it has to be positioned but sometimes in digging stumps it will break a root or pull the front tires off the ground like the tractor weighs nothing.

And wasn't it Charles Atlas that said "Give me a place to stand and I'll move the Earth?"

Or was it Mighty Mouse that said, "Give me a long enough lever and I'll move the Earth?" /w3tcompact/icons/smile.gif

(We think of our BX as Mighty Mouse)

del

 

[campster]

Re: BX Boulder Mover

I think Archimedes was the guy with the fulcrum

 

[TresCrows]

Re: BX Boulder Mover

You would be correct in that the coefficient of friction should typically be much less than 1.0. Moving the 2000 lbs approx boulder will likely not require anywhere near 2000 lbs force on flat ground. The trailer limit capacity of the BX is 1765 lbs. This limit, for a tractor, is not the load rating of the frame or the transmission but of handling and safety qualities when that limit is exceeded especially given lawsuit happy Americans. Since the BX seems quite happy moving my 350 lbs box scraper with teeth down and a near full bucket it should be able to tug that boulder. I doubt the boulder will require as much effort. The tugging force limit is not trailer load capacity but is limited instead by traction available. As to bending the blade of the FEL when used as a lever, I doubt that also, it is pretty substantial but if that were your concern then use the blade near the corner. I am pretty certain the engineers accounted for the forces the FEL can generate when they sized the steel in the tractor and FEL and pretty certain that the transmission is able to absorb full engine power of 22 horses and 41 ft.lbs of torque without damage, it is far more likely traction will not allow maximum force limits to be reached before wheel spinning occurs thus relieving the loads. I have never dissassembled a hydrostat transmission but they are similar to the variable output hydr/turbine pump on jet engines and they have sheer shafts etc and I imagine there would be a load sensing valve or a sheer shaft in our tractors also or some other means of allowing engine forces to be partially disengaged or fully disengaged when force limits reach a damaging level. You can break anything, common sense should always rule the day. Obviuosly if I put the pedal to the metal and the transmission stalls then it is time for plan B. J

 

[Roy]

Re: BX Boulder Mover

TresCrows… You are correct about being less than 2000 lbs. I over simplified. To calculate the force required for rocking, one would have to know the exact pivot point, lift distance from the pivot point, and the mass. Difficult for an odd-shaped object. Now for moving, that calculation is real tricky for what you are attempting. As Wheeldog points out, who knows what that factor will be. Unlike your truck that offers wheels and balance designed for forward movement, you're dealing with a skid and a rock. Even if you place logs under the skids, there will be resistance, and soil conditions will play a big role.

Even if using the truck, the system can only be as successful as the weakest point. Have witnessed many failures (and successes) of neighbors and friends attempting to pull objects with 4x4's (sheds, stumps, rocks, etc.). The failures were the cases that their tires were nicely designed for pavement contact. Once they were on turf, the weakest point in the system was where the tires meet the grass, little resistance. So all the power translated to the path of least resistance, a stationary truck with wheels spinning.

Now, I personally hope that you do succeed; I have to root for Bamm-Bamm. But, I don't want to see you push it beyond the capabilities, and possibly damage the tractor or truck.
It's one of those jobs which you don't know if it's possible until you try it. If it works, pictures would be welcome. Good luck.

Wondered where my post went. I didn't realize that this thread had so much activity last night that it split into 2 sections, and I was reading half the new responses. I now see that you do have it pretty much figured out, and are going to back-off if it looks like the unit is being over stressed. Good luck with the project.

Wheeldog… I have been very aggressive with my FEL. When digging up small stumps, I have driven the FEL underneath the root system several times, and pulled up aggressively. Rather than bending, if it is too much resistance, the entire tractor will lift up (back wheels, or tip to the side). Have had two wheels off the ground at least a foot (just let the tractor slowly back down by reversing the FEL movement). Have also rammed stumps to see if they would push over using the edge; enough of a force that, if the stump didn't give, the unit would quite noticeable shake upon impact. I believe that the strength of the edge exceeds the capability of the tractor. No dents to date, no bends (just missing paint).


Roy