What Is a 3PH Designed To Do?

pitt_md · Jun 19, 2009

Reg said:
I think you have either mis-read or mis-understood a few things.
Attend a tractor pull some time; It isn't about WHERE the drawbar actually IS and it certainly doesn't bring the front down.
The geometry PERMITS the front of the tractor to come UP - to a point of maximum traction and stability.

Unlikely that a tractor would flip backwards from a blade or plow encountering a major obstruction.
Not saying it couldn't happen, just that the speed would have to be way higher than would be prudent for the task.
Yes, (if I am to believe the Ferguson story) the original purpose was to lift and carry ground engaging implements..... which would be "pulled" in the next row after the turnaround.
Whatever pattern you drive you are faced with sharp turns and having to at least drive over the same ground more than once.
Lifting the implement from the ground during the turn makes so much sense in so many ways, too many to list.

Catch a big tree root with a plow and watch the front end come up. Even going slow if your tractor does not stall the energy is going to go someplace and if you have traction the only place left is up. I have "performed" this manuver more than once and it scares the bejesus out of me every time.

pat32rf · Jun 23, 2009

If those big rear tires have enough traction and the engine has enough power then you are going to lift the front end when the item hooked to the drawbar hits a big enough obsticle. Ditto when trying to get a large load in moption from a standstill. (just watch a heavily loaded 18 wheeler trying to start up on a paved hillside).
Its a function of the rotational torque applied to the rear axle. This is why you should always start in reverse if your rears might be frozen into the mud in the mornings.

NewToy · Jun 23, 2009

I pulled out about fifty metal fence posts with my three point the other day. A short length of 1/4" chain and a grab hook, one pull and they were outta there. Sure beat the wiggle and pull method I was doing sans tractor.

John

Soundguy · Jun 23, 2009

I like my loader for pulling posts too.. loader and a chain and a lil hyd pressure and the pop right out.

soundguy

slowzuki · Jun 24, 2009

3 ph was designed for pulling a plow. Draft control was a neat innovation to let a smaller tractor pull a bigger plow. It yanks up on the plow when it pulls to hard, transfering weight to the rear tires for traction and reducing the depth of cut. It also can pop the front tires of the tractor off the ground.

The 3 ph was invented in the days of horses pulling things and has been extended to hundreds of other implements since. Notice many old tractors had no stabilizers so the hitch was semi useless backing up as it swung all over.