BX25 FEL CYLINDER ENHANCEMENT

[Nightforce]

Wait, ok the rear pin is 3/4" as you said, OK a simple bushing
at the rear will suffice.

Cham"b"er or Cham"f"er ?

It would save a lot of machining time and money if the chamfered
edges were just tagged w/ a belt sander yes?

Just this one change, w/o playing with pressures will more
than double the lifting power correct?

HA, you got me!

Cad is where it's at and has saved my lily white butt more times that I care to admit...

Chamber vs Chamfer...... Spell Check is guilty as charged! LOL

I just added Chamfer to my dictionary...

I'm using Solidworks and this is what happens when someone asks for a finished design and I hurry to get-er-done! LOL

Belt sand instead of chamfer, of course! Bottom line here is the parallelism between the pin hole and block face so no binding occurs..

Correct again, this change affects no other part of the tractor..

Also, what I failed to add to the new end block is a 1/8 NPT pipe tap for lubrication.

 

[Artisan]

Nightforce,
You are more up on this then I, perhaps
CLICK HERE and get a quote for 4- custom
cylinders built to our specs.
(I got 20.625" closed C to C dims)

 

[Nightforce]

Nightforce,
You are more up on this then I, perhaps
CLICK HERE and get a quote for 4- custom
cylinders built to our specs.
(I got 20.625" closed C to C dims)

Well ain't that just dandy!

Looks like I can order my cylinder of choice configured with the ends I need right from the factory!

COOL!

 

[Nightforce]

Nightforce,
You are more up on this then I, perhaps
CLICK HERE and get a quote for 4- custom
cylinders built to our specs.
(I got 20.625" closed C to C dims)

Artisan,

I don't know if you saw this out not but if I'm understanding this correctly for custom cylinders it's $1,000 minimum....If I'm understanding it correctly...



Still, the standard cylinder costs about $180 then we have to modify it which naturally adds cost.

4 cylinders @ $250 each and we're at $1,000...

I also have to find out the port fitting sizes on the factory cylinders.

 

[Artisan]

We need to shop this. Might I suggest;
Use the online submission parameters at Baileys and get a quote for the minimum, THEN we
can take that written quote and redact the selling cost numbers and shop it.
Email me the quote and we can both shop it. There are a LOT of hydraulic
cylinder shops, as a matter of fact there is a good sized shop that does
this work close to me. Once I get the name I bet you recognize it.

 

[Artisan]

IF THERE ARE ANY OTHER GUYS WHO ARE S E R I O U S AND
WANT A PAIR OF THESE PLEASE CHIME IN, BUT AGAIN, o n l y
IF YOU ARE SERIOUS, PLEASE. You will fund me / us prior to ordering
if we can get a group buy. No returns unless defective then only
a part trade, no refunds.

 

[IslandTractor]

Has anyone done this modification before on a BX??? Seems like a bad idea to me. Kubota engineers designed the FEL to match the rest of the tractor, especially the front axle. Ballast is also a consideration. It may be technically possible but you would be turning a very reliable tractor into something with a good likelihood of breaking.

 

[Artisan]

Well, yea... it is a bit of a gamble. It is a no ballz, no blue chips
kinda situation IMO.

Heck, I caught crabs a couple times too, but it was worth it...
Nothing ventured, nothing gained yes? I see a robust assembly.

If I am wrong I will get to pay for my mistake. Life goes on...

 

[IslandTractor]

How much lift do you expect to gain? My former Kioti CK20 loader lifted just over 1000lbs to full height but the front axle on that tractor is massive compared to the BX. I would imagine conservative Kubota engineers build in enough of a safety factor that taking the BX loader from 600lbs to 800 probably is OK but I wouldn't go beyond that. The bucket is too small to lift much more than 600lbs of sand anyways so I'm not sure what the extra FEL capacity will get you unless you are planning a grapple addition too. If you need to dig more just turn that puppy around and use the BH. Or, just upgrade to a B21 (or Kioti). Personally I've always admired the BX TLB and think it is perfect just the way it comes from the factory.

 

[Artisan]

Well, the numbers indicate double + , so what is the lifting power stock, do I
remember correctly it is a measly 400 pounds or so? I think so. So double the power
means I might expect double the lifting power, so nothing major here.

I have a grapple AND bolt on teeth, all weigh maybe 150 pounds,
so I loose that to start. It will be a most welcomed improvement.

It is like this, if you can not manage a bigger carburetor on your
car do not buy it. If you are disciplined and can manage High Performance
machines you will be ESTATIC and Grin from ear to ear MORE.

 

[IslandTractor]

I'd say you need a bigger tractor.

Stock lift on the 25 is about 600lbs as I recall. Doubling that to 1200 puts you way over what those front axles were designed for. How do you think you can lift 1200lbs without breaking your axles? Actually you probably will simply lift up the rear of the machine as the BH only weighs about 600lbs so unless you get crazy with ballast all your going to accomplish is to screw up a perfectly nice BX and turn it into a rocking horse. It's your tractor though. Have fun and post photos.

 

[Nightforce]

There's a lot of truth in everyone's statements.

Machines are designed to meet specific parameters set forth early in it's design. Does anyone know the actual loads the BX25 can actually endure over time? I know I don't and I don't pretend to. While I did think about the front axle I may be guilty of not giving it the consideration it's due.

Specs.



Counterweight is another important consideration. As the FEL load increases the front axle / wheels become the fulcrum or pivot point. To counteract this load additional load must be added to the rear to prevent lifting the rear wheels off the ground. According to the data above, the BX25D sporting the front end loader and backhoe weigh in at 2,700 pounds.

Having the backhoe attachment in place clearly adds a lot of ballast to the equation. According to Kubota, the backhoe attachment adds an extra 617 pounds

One could contact Kubota and pose the question whether or not the force of a 2" cylinder compared to that of a 1.5" cylinder is a lethal combination.....but I'm almost certain they'd plead the 5th due to liability issues.

Caution is always advisable anytime we uses these machines whether completely original or slightly modified.

Before I move forward I'll see if I can gather more information especially regarding the front axle...

 

[Nightforce]

Not to muddy the water but here's a few specs on the loader itself.

 

[IslandTractor]

Not to muddy the water but here's a few specs on the loader itself.

That's useful.

FWIW, from my perspective the BX25 and earlier siblings were never designed to compete or do the same work as larger CUTs. They are mostly used around the house or smaller properties doing work that a man with a shovel and wheelbarrow could do. The BX works about as well as three or four men with shovels and wheel barrows. Men with wheel barrows cannot lift and move half ton rounds of hay and neither can a BX. A few men with shovels and wheelbarrows cannot move a half ton boulder. Neither can a BX. A few men with shovel and wheelbarrows could dig out a moderate size stump and so can a BX.

If you need to move something that weighs more than 500lbs, get a bigger tractor. The BX is perfect as is.

 

[Nightforce]

Like everything in life, all good things take time!

Modifying the set of cylinders I described on page 2 requires an adapter in order for them to fit in the stock loader arms. I machined the blocks below and when I get a few bucks put aside I'll order the cylinders and modify them by removing the standard mount then welding on these..

Nothing fancy, just some low carbon steel milled, drilled, and tapped..

 

[Nightforce]

Personally, I do not like running my rpm's in the 3,000 range and much prefer them in the 2,200 to 2,500 rpm range. Having a slightly larger, (2.0" diameter) hydraulic cylinder will help me at the lower end of the pressure curve.

BX25D

As you can see by the information below, there is a significant difference in pump output pressure at an idle vs the working rpm range. Do the math and see how this difference equates to force and lifting ability.


Hydraulic Pump Pressure

1500rpm



3000rpm



Chart

 

[Nightforce]

Just to keep the thread alive, I decided to add an intermediate step the improving the performance is the front end loader.

I bought some shims and adjusted the pump pressure to the front end loader. As we've all seen, Kubota sets this at about 1775psi. With the appropriate shims I was able to boost the output pressure to 2000psi at 2500rpm.



Before I make any changes to the cylinders, I felt this was a great intermediate step. I'll gauge it's performance throughout the fall and winter to see just how much of a difference adding 225 psi really makes...

More to come I'm sure!

 

[Nightforce]

I found a Kubota add for the BX series and they state the working capacity of the front axle is 1800 pounds.

 

[Tomtint]

I found a Kubota add for the BX series and they state the working capacity of the front axle is 1800 pounds.

One would assume that's Gross capacity. ..1/2 the weight of the tractor and attachments as well as a 600 lb cargo in the bucket at full lift.

 

[IslandTractor]

One would assume that's Gross capacity. ..1/2 the weight of the tractor and attachments as well as a 600 lb cargo in the bucket at full lift.

Agree. There is also the question of static versus dynamic load. Lifting is one thing, traveling on a bumpy path with a heavy weight also needs to be part of the equation.

Kubota is pretty conservative in how they engineer their tractors but they also make "compromises" to keep the total weight down. The BX class in particular is primarily designed and optimized for lawn care rather than grunt work in the field or ground engaging activities. I'd imagine the consistent undersizing of front end loaders through the BX, B and even L lineup (compared to for example Kioti and Mahindra) is related to their efforts to keep weight down and their use of smaller front axles. Compare the size of the BX axle (and tractor weight) to a similar horsepower Kioti CK2510 or 2610. Notably different.

The BX is a great tractor but it isn't ever going to compete on loader power. I'd leave it just like Kubota designed it knowing that it probably could have a stronger loader but that as is it is near perfect. If you need a bigger loader get a bigger tractor.