Kubota L3800

[eyi]

I think you are talking about GPM vs. PSI, if that is correct... I'll try to explain, which I'm not good at.

If you compare 1 gallon per minute (GPM) to 10 gallons per minute but both produce the same PSI, both would be able to raise the same amount of weight but the 10 GPM would be 10 times faster. Since they both have the same PSI, the force to raise a certain amount of weight is the same for both, (the 1 GPM will get there, just a lot longer). Thus doesn't matter about strength, just speed.

If you have 2 different hydraulic cylinder, with the same exact PSI (pressure per square inch) and say the larger cylinder is 3 inch vs. 2 inch. The larger cylinder can lift more weight (strength) than the smaller 2 inch cylinder. Since more pressure can be applied to the larger 3" surface, so even if it's the same pressure, you have more surface to apply that pressure to.

Now because the 3" cylinder has more volume, it takes longer to fill up vs. the 2" cylinder and this is where how fast you can fill (GPM) comes into play... if you have a low GPM, it would take a longer time to fill a 3" vs. a 2" (thus, just speed).

Not sure if that's a good explanation....

Tractors with higher PSI but with the SAME SIZE diameter cylinder can lift more weigh. (clear as mud ??)

Hum, I think I understand...Which is a tractor like the MX has either larger cylinder and/or higher PSI and as a result has a higher lifting capacity than the L3800 ?

So the GPM spec which is put forward in the marketing documents just to give people a sense of work speed ?

And the PSI isn’t put forward because they instead provide the lifting power which is the result of both PSI and size ?

 

[Fallon]

Tractors generally run at 2,500psi, skidsteers at 3,000, excavators at over 5,000 & really old tractors a 900-1,800. Increases in capacity are all done by bigger cylinders or better geometry. You need more GPM to fill the bigger cylinders at the same speed as the smaller ones. But low GPM will still move the same weight on the same cylinder, just a but slower.

 

[old and tired]

....has a higher lifting capacity than the L3800 ?

Kubota makes it pretty easy for you, the model number on the side of the loader equals the amount of weight in kilograms that the loader can lift. (measured at the pivot points of the bucket)

So your tractor might have LA524 so roughly 1000 pounds but that is measured at the bucket pins. Kubota used to measure lift ability from the middle of the bucket - My LA463 is the same lift capacity as the LA524 (old way of measuring vs. the new way) But I raised my pressure so it would lift more!

The MX loader I think is LA1065 - so basically twice the lift - the tractor is much heavier, wider and longer to be able to handle the extra weight. It's a beast of a tractor but there are trade offs.

This is an informative video about loader numbers... Understanding Kubota loader model numbers - TMT - YouTube

 

[ovrszd]

Hum, I think I understand...Which is a tractor like the MX has either larger cylinder and/or higher PSI and as a result has a higher lifting capacity than the L3800 ?

So the GPM spec which is put forward in the marketing documents just to give people a sense of work speed ?

And the PSI isn’t put forward because they instead provide the lifting power which is the result of both PSI and size ?

1st question, yes.

2nd question. GPM information is critically important if adding hydraulic functions to a tractor. It gives you a guide as to how fast and how large of hydraulic function can be performed. With a true 3rd function feature on a loader you may be performing 3 functions at once. In that situation you will be very interested in the tractors' max GPM.

3rd question. Most systems run about the same PSI. This is based on how much the average hose, valve, cylinder can stand. So as a tractor grows, cylinder size grows to get more power. GPM growth is secondary to maintain speed.

 

[LD1]

What is the pressure rating of the log trailer and what is it rated to lift at said pressure?

Going to a bigger tractor wont make it lift more because most tractors, as mentioned, are right in the 2500psi range.

Going bigger will only make it lift FASTER.

You either need higher pressure or a larger diameter cylinder to lift MORE.

 

[eyi]

Would my cat 1 implements fit on a cat 2 MX tractor without issue ?

 

[eyi]

Would my cat 1 implements fit on a cat 2 MX tractor without issue ?

Since I wrote this post,I’ve found several one indicating that there is simple sleeves solution to this issue. On the other hand each implement has his own «*drive shaft*» connecting to the tractor PTO. I suppose a cat 2 tractor’s 3 point arms are longer than the ones on my small 3800 which indeed I have always found pretty short.

So would those «*drive shafts*» still be ok or needed to be changed ?

Thanks agian

 

[ovrszd]

Since I wrote this post,I’ve found several one indicating that there is simple sleeves solution to this issue. On the other hand each implement has his own «*drive shaft*» connecting to the tractor PTO. I suppose a cat 2 tractor’s 3 point arms are longer than the ones on my small 3800 which indeed I have always found pretty short.

So would those «*drive shafts*» still be ok or needed to be changed ?

Thanks agian

Most times the shaft length is fine. Rarely here on TBN someone will mention that they had to have a longer PTO shaft.

 

[Bavarian]

1st question, yes.

2nd question. GPM information is critically important if adding hydraulic functions to a tractor. It gives you a guide as to how fast and how large of hydraulic function can be performed. With a true 3rd function feature on a loader you may be performing 3 functions at once. In that situation you will be very interested in the tractors' max GPM.

3rd question. Most systems run about the same PSI. This is based on how much the average hose, valve, cylinder can stand. So as a tractor grows, cylinder size grows to get more power. GPM growth is secondary to maintain speed.

In regards of your statement in question 3, the hoses, lines and valves are pretty much the same in the different systems. How much pressure the system can handle is determined by the style of the hydraulic pump.
A simple aluminum hydraulic pump doesn't stand as much pressure as a cast iron pump.
Ask me how I figured out. Turned up an alluminum pump to the pressure of a cast iron on an excavator. A few days later the customer called. The crankcase of the engine was filled up with hydraulic oil until the pistons hit the oil and the engine died.
The aluminum pump housing did not crack, but the seal to the timing gears got pushed out. Simply put, the pump wasn't designed to stand the pressure.

A colleague of mine cracked even a cast iron pump. It's easy.

 

[old and tired]

...fit on a cat 2 MX tractor without issue ?

The issue is IF you have light duty attachments and try and run them on a more powerful Cat 2 tractor. You can bend or break things if they are not designed for the higher HP.