YM 2000 - Roll Over

[VT_Hokie]

I think you all have done a good job of bringing out the discussion on tire filling. Always thought that more than 50% is defeating the purpose but can see why 75% is recommended now. Here are my Questions:

At what angle would a tractor role if it were stationary without filled tires? With filled tires?

And here is one a little more complicated for you, at what angle would it roll going lets say 5 mph if the low wheel would drop 12 in in a hole or the upper would go over up and over a 12in log? This is not a simple change in angle question as you are also dealing with momentum of the tractor's roll.

Here are some perimeters....

Since you (you'all) are doing the math you can make what ever assumptions necessary, but how about you start with these...

Smaller Yanmar, 1400 lb, 44 in rear base

Bigger Yanmar, 2100 lb, 48 in rear base

Filled tires adding 100 kg a piece. For some reason I recall someone saying filling tires adds 238lb a piece. If you know the true weight feel free to give the good data. Just let us know the size of the tire.

I am trying to relate this information to products that are available on the market for measuring tractor angle and old rules of thumb. Seems like 15 degrees is in everyones safety margin, but how far out can you go with a Yanmar? /forums/images/graemlins/wink.gif

 

[Paddy]

The exact roll point is bases on the greatest unknown, the center on mass of the tractor, excluding the wheels. Also, in a static problem the up hill tire could be pressing 10lb and still be up right

By adding the motion, this static problem went to dynamic. Gets tough real quick. Angular mometom is more diff to start with mass far from the axis. But as we know the flywheel...hard to stop as well!

Patrick

 

[pruntyc]

Then there is the fact that a wide front end doesn't make a tractor more stable, just makes one think it is. As it doesn't keep it from rolling over, like it would at first seem like. Sure makes one wonder what really works and what doesn't. /forums/images/graemlins/grin.gif

 

[sls]

Didn't mean to stir things up!! Just wanted everyone to be careful. No amount of fluid in a tire, ROP, or dynamic equation can prevent human error. JUST BE SAFE and enjoy your time on old "Yanny"

 

[Paddy]

I think you did what you intended, remind us all to be carefull.

I have some hilly S. Indiana ground. Hills scare me big time with out the trig!

patrick

 

[Cord]

</font><font color="blue" class="small">( Then there is the fact that a wide front end doesn't make a tractor more stable, just makes one think it is. As it doesn't keep it from rolling over, like it would at first seem like. )</font>

Well, this isn't quite true. Yes, the axle pivots on a central point, so wide front or not, there is no difference in the initial resistance to over turning. That changes whenl the stops hit the frame. Then the wider stance becomes effective. Where as a narrow front tractor will flip over, the wide front tractor will tip onto two wheels and hopfully recover.

 

[pruntyc]

That is not true, from what Len says an insurance company proved a few years ago. It made no difference at all.

 

[Gizmo36]

pruntyc I am glad you said that and not me.

 

[Paddy]

Len who and what study was done?

 

[Eddie]

( Then there is the fact that a wide front end doesn't make a tractor more stable, just makes one think it is. As it doesn't keep it from rolling over, like it would at first seem like. )
Well, this isn't quite true. Yes, the axle pivots on a central point, so wide front or not, there is no difference in the initial resistance to over turning. That changes whenl the stops hit the frame. Then the wider stance becomes effective. Where as a narrow front tractor will flip over, the wide front tractor will tip onto two wheels and hopfully recover. )

Why did all professional tractor pullers have to go to wide front ends a few years ago? Why did the Federal Government stop the manufacter of 3 wheel ATVs? Because a wide front end is more stable. I have driven both wide and tricycle front end tractors for 40 years and from experience I can tell you it is true.