DK50SE HST No Ballast Lifting

[IndyIan]

I move 4x5 hay bales without ballast on my driveway fairly often. I've got to go down a 30' steeper section to drop the bale off near the feeder, so all I do is slide the bale on the ground for that part. You can do this with the bucket as well for short distances too.

 

[GManBart]

I don't have a DK50SE Cab (unfortunately, as it's a great tractor...ran one briefly a while back), but I did a pretty controlled experiment along these lines somewhat unintentionally. The steel block that I sourced from the local scrap yard to make into my counterweight weighed exactly 1,300lbs. We transported it home in my neighbor's dump truck, and I drove my tractor with FEL and forks over to his place to weld the block into a counterweight. We had dumped the block of steel onto some sections of 4x4, and I was able to just barely lift it with the FEL without lifting the rear tires (level concrete). I didn't have anything on the 3pt because I was going to be driving back with the counterweight on my tractor. Also, my rear tires aren't loaded. My loader is rated at lifting 2,638lbs to max height (at the pins). The rear tires were pretty darned light, and an abrupt move on the FEL control, or the HST control would cause the tires to raise.

So, with all that, I'd say probably something in the ballpark of half the listed max lift would be doable on a flat, level surface if you're careful.

 

[IndyIan]

I do have the rears loaded which must help a bit. I also unloaded my 1000-1200lb box blade with no ballast off my trailer on level ground. I could back up in 2wd but I wouldn't lift anything with my bucket that high on uneven ground, without the box blade on the back. Half of max lift does sound about right for level ground.

 

[CJONE]

Imagine a tractor with a very heavy implement on the 3PT. The balance/pivot point would be the rear axle. Imagine that 3pt weight was so heavy the front wheels were actually off the ground. Now, add some weight to the FEL and the front wheels will again touch the ground but they will not exert the same pressure on the front wheels/axle as they would if there was no massive weight on the back of the tractor. Weight on the 3PT or at least behind the rear axle will take pressure off the front axle when lifting the FEL. I agree loaded rear tires would not take weight off the front axle even though they would stabilize the tractor but weight behind the rear axle would remove weight from the front axle by pivoting over the rear axle.

Until you lifted enough weight to lift the rear tires and your ballast off the ground then all the pressure is again on the front axle. all your ballast does is keep the rear on the ground. I do agree if you were to hang 3000lbs off the rear THEN it would be unloading the front but heck you could be riding wheelies around with that much weight!! Anyway I have 1100lbs on my three point and loaded tires, I can still lift the rear off the ground with the rollback but it seems to be just about right. 1500 would be better but I still need to haul this thing and my 1/2 ton fusses already!! CJ

 

[IslandTractor]

Until you lifted enough weight to lift the rear tires and your ballast off the ground then all the pressure is again on the front axle. all your ballast does is keep the rear on the ground. I do agree if you were to hang 3000lbs off the rear THEN it would be unloading the front but heck you could be riding wheelies around with that much weight!! Anyway I have 1100lbs on my three point and loaded tires, I can still lift the rear off the ground with the rollback but it seems to be just about right. 1500 would be better but I still need to haul this thing and my 1/2 ton fusses already!! CJ

I don't believe it is all or nothing with regard to 3pt ballast taking pressure off the front axle. Any weight behind the rear axle would contribute to taking pressure off the front. Some engineer or physics wonk could do the relevant force vector sums but I cannot see how the pressure on the front axle would go from negative (big weight on 3pt that almost or barely does lift the front end) to carrying the entire 1000 lb load you pick up with that same tractor. Imagine for example that the rear ballast was enough to barely raise the front wheels. Now add another 500lbs to the rear...front wheels now in the air. Next add 1000lbs to FEL. Is the pressure on the front axle now 1000 or 500 lbs? I would say 500lbs which means the rear axle is taking some of that 1000lb load.

 

[GManBart]

Until you lifted enough weight to lift the rear tires and your ballast off the ground then all the pressure is again on the front axle. all your ballast does is keep the rear on the ground. I do agree if you were to hang 3000lbs off the rear THEN it would be unloading the front but heck you could be riding wheelies around with that much weight!! Anyway I have 1100lbs on my three point and loaded tires, I can still lift the rear off the ground with the rollback but it seems to be just about right. 1500 would be better but I still need to haul this thing and my 1/2 ton fusses already!! CJ

If 3,000lbs would take weight off the front axle, 1,000lbs would as well, just to a lesser extent. When we put weight on the 3pt, it turns the machine into a teter-toter, with the rear axle as the hinge point. Any weight on one end removes weight from the other end....it has to.

 

[Sysop]

I do have the rears loaded which must help a bit. I also unloaded my 1000-1200lb box blade with no ballast off my trailer on level ground. I could back up in 2wd but I wouldn't lift anything with my bucket that high on uneven ground, without the box blade on the back. Half of max lift does sound about right for level ground.

That does act as a ballast for stability and it does help keep the rear tires on the ground, but it doesn't do anything to reduce wear in the front axle components, for that you need the weight behind the rear axle. Safety-wise for any tractor I'd say you're right on the money at "half of max for level ground", but to prolong the life of my hardware I try to keep as much on the 3 point as I'll be working with on the front (even with my loaded rears).

 

[CJONE]

Let me try to explain it this way. I can lift the back end up with over 1200lbs of weight on the 3 point. I am guessing 1400 would be an equalizing point. That means I would have to hang 1500+ pounds off the back to even start removing weight off the front axle and I am guessing about a 4 to 1 ratio between the rear axle and weight center point to the rear axle and front center point at best, probably 6 to 1 without measuring so to take off 1000lbs off the front axle I would need 5400lbs. That is not going to happen. I'll use it for what it was designed for and it has been great for the first 350 hours. CJ

 

[CJONE]

If 3,000lbs would take weight off the front axle, 1,000lbs would as well, just to a lesser extent. When we put weight on the 3pt, it turns the machine into a teter-toter, with the rear axle as the hinge point. Any weight on one end removes weight from the other end....it has to.

If you can unload [lift] the rear tires off the ground your teter toter point IS the FRONT axle right? So ALL the weight is on the FRONT axle including the weight you added. Now the only time you can remove weight off the fron axle IS when the rear stays on the ground. Like the post obove says that IS alot of weight. CJ

 

[IslandTractor]

If you can unload [lift] the rear tires off the ground your teter toter point IS the FRONT axle right? So ALL the weight is on the FRONT axle including the weight you added. Now the only time you can remove weight off the fron axle IS when the rear stays on the ground. Like the post obove says that IS alot of weight. CJ

I still don't see it your way. Consider another similar situation where maintaining appropriate balance in weight carried by front and rear axles is important. When towing a trailer, tongue weight is important. Why? Because too much weight on the rear hitch will unload the front axle and make for squirrelly handling. So even 1000lbs of tongue weight is too much for most vehicles. However, if you move that 1000 or even 2000 lbs to a point directly over the rear axle, as with a 5th wheel or gooseneck hitch, suddenly "tongue" weight is a non issue. The front end balance is not changed whether the trailer is attached or not to a gooseneck.

 

[deezler]

Every time these threads come up I just have to shake my head.

Sure, not everyone is a physicist or engineer, but this is a pretty basic concept that seems to allude most people.

There is no "point" at which weight on the 3-pt "starts" to unload the front axle. The effect of ballast in the rear tires is NOT negligible for loader capacity. it is all a continuum of mass distribution. Sure, more weight further back on the tractor is better at countering a heavy load on the front-loader. But there aren't rules about what works and what doesn't. It all has an effect.

Center of mass - Wikipedia, the free encyclopedia

 

[IslandTractor]

Every time these threads come up I just have to shake my head.

Sure, not everyone is a physicist or engineer, but this is a pretty basic concept that seems to allude most people.

There is no "point" at which weight on the 3-pt "starts" to unload the front axle. The effect of ballast in the rear tires is NOT negligible for loader capacity. it is all a continuum of mass distribution. Sure, more weight further back on the tractor is better at countering a heavy load on the front-loader. But there aren't rules about what works and what doesn't. It all has an effect.

Center of mass - Wikipedia, the free encyclopedia

The rear tire/wheel ballast is certainly very relevant to stability when using the loader. The debate here is not total ballast or stability so much as whether ballast aft of the rear axle takes pressure off the front axle when lifting.

 

[k0ua]

Please look at post #1 where the poster did actual scale measurements with ballast on the rear. This is a thread that references another thread where TX Jim doubted that putting any weight on the 3pt would "unload" the front axle. He proved himself wrong by doing actual measurements.

http://www.tractorbynet.com/forums/kubota-owning-operating/290328-ok-guys-today-weight-day.html

 

[IslandTractor]

Please look at post #1 where the poster did actual scale measurements with ballast on the rear. This is a thread that references another thread where TX Jim doubted that putting any weight on the 3pt would "unload" the front axle. He proved himself wrong by doing actual measurements.

http://www.tractorbynet.com/forums/kubota-owning-operating/290328-ok-guys-today-weight-day.html

Exactly.

 

[deezler]

Sorry I worded my last post badly. I did not mean to imply that weight behind the rear wheels was unable to reduce load on the front tires. I just meant it didn't begin to act at some random point, that it's all a sliding scale.

The entire equation is really quite simple by engineering standards. If you know total mass and it's relative distribution, you can calculate the center of mass. Then the distance from the C.O.M. to each axle determines the moment reaction to support said mass, i.e. the load on each axle.

 

[IslandTractor]

The entire equation is really quite simple by engineering standards. If you know total mass and it's relative distribution, you can calculate the center of mass. Then the distance from the C.O.M. to each axle determines the moment reaction to support said mass, i.e. the load on each axle.

That is the clearest explanation. Thanks.

 

[k0ua]

Here is a drawing that another member did to help explain the forces at work here.

 

[GManBart]

Let me try to explain it this way. I can lift the back end up with over 1200lbs of weight on the 3 point. I am guessing 1400 would be an equalizing point. That means I would have to hang 1500+ pounds off the back to even start removing weight off the front axle and I am guessing about a 4 to 1 ratio between the rear axle and weight center point to the rear axle and front center point at best, probably 6 to 1 without measuring so to take off 1000lbs off the front axle I would need 5400lbs. That is not going to happen. I'll use it for what it was designed for and it has been great for the first 350 hours. CJ

Nope, physics, and levers don't work that way. If you put 1 pound on the 3pt, it's taking weight off the front axle. Every pound you add to the 3pt is taking weight off the front axle, because it's gradually transferring it to the rear axle, and eventually, you could have zero on the front axle (if the tires lift).

In a practical sense, my loader can lift almost as much as yours (2,638lbs at pin), and with no rear ballast, I was able to just barely lift 1,300lbs (weighed as such). With that 1,300lbs turned into a 1,350lb counterweight, I can put my forks under something I can't lift at all (FEL hits relief) and the rears stay planted. That is clearly taking a lot weight off the front.

Most importantly, as you said, it should be used as designed, and Kioti specs 1,047lbs on the 3pt for FEL use. I don't think they did that by mistake....it's to protect the front axle, and keep you safe.

 

[rjwerth]

Until you lifted enough weight to lift the rear tires and your ballast off the ground then all the pressure is again on the front axle. all your ballast does is keep the rear on the ground. I do agree if you were to hang 3000lbs off the rear THEN it would be unloading the front but heck you could be riding wheelies around with that much weight!! Anyway I have 1100lbs on my three point and loaded tires, I can still lift the rear off the ground with the rollback but it seems to be just about right. 1500 would be better but I still need to haul this thing and my 1/2 ton fusses already!! CJ

And once you have done that, you have exceded the specs of the loader (and probably the whole tractor). Others have already given the official specs of what is needed to achieve the maximum lift capacity. Follow that and the front axle lives to see another job.

 

[Sysop]

I honestly don't see how everyone can set and argue simple physics.

When you lift something with the FEL, not only do you have the weight you are lifting on the front axle, but some weight also transfers from the rear of the tractor due to the FEL creating leverage on the front axle.

And the exact opposite is true as well...

When you lift something with the 3pt, not only do you have the weight you are lifting on the rear axle, but some weight also transfers from the front of the tractor due to the 3pt creating leverage on the rear axle.
---------------------------------------
I honestly don't see how everyone can set and argue simple design facts.

Front axles aren't built as large and strong as rear axles.

THEREFORE;
When lifting things with the 3pt, there is not as much concern of breaking or wearing out the rear axle because they are made MUCH more stout than ANY front axle.

And the opposite does not hold true...

When lifting things with the FEL, there should be concern over breaking things or premature wear because they're made much smaller than the rear axle.
---------------------------------------

Now with that being said, the best method to prevent wear and breakage of your machine is simply to ballast behind the rear axle you can counter some of the weight transfer effect when using the FEL, not totally but to a point. The point is not to "ballast out the back so no extra weight is put on the front loaded versus unloaded", it is to reduce the amount of transfer of the rear weight on to the front axle and keeping the rear axle supporting more weight than the front. To do that properly, with the geometry involved (3pt doesn't have as much leverage holding weight closer to the rear pivot point as the FEL does with the front pivot point) you need more weight on the 3pt than you will be putting on the FEL...

...and it's been said before, but perhaps it needs said again; adding weight to the rear tires themselves only provides extra weight for the FEL to transfer to the front. To properly use the pivot of the rear axle you must use 3pt ballast.

Anytime there are official specs to use, do so. Don't just think that because the back tires are still on the ground everything is ok... Balance is the key to life.