Bump up lift capacity of L3400/LA463 Loader

[J_J]

ht1, do you know what RPM you set/read 2500 psi at?

You can set the pressure at any rpm, but only if you are doing work like raising your bucket to the max and hold it there, then the relief will relieve, and read the gage. Even the PTO just sitting there and turning with no load, there will not be a lot of pressure. Pressure is developed when you try and stop or by putting something in the path of the fluid, like a cylinder, a hyd motor, or hydrostatic transmission. Years ago, I thought it was odd that I didn't have 2750 psi on my lift cylinders, and then I realized that some things don't take much pressure to operate. However to get maximum out of the system The design people have determined that a certain cylinder will lift a certain load if the rod end is put at a certain location. Most all the cylinders out there can do a lot more work, if the geometry of the cyl and mounting location is correct.

 

[LD1]

LD1,

Did you take into account the angle that the cylinder is to the lifting arms. I posted some data in the Power-Trac Forum post #116

Short answer to your question is yes.

I actually figured two way and came up with virtually the same #'s.

The first way I figured it was taking measurents off the loader of the distances between all the pins. Then using geometry/trig I factored the angle of the cylinder as well as the lever effect of the bucket being ahead of the lift point. If I still had my scratch pad with the measurements and formulas I would upload it but I think I threw it away. If I get real bored I might measure and draw it out again.

The second method was to use the sroke of the cylinder divided by the total travel of the loader. (raise height + ouw far below grade it can be lowered). This gives an effective % ratio between the loader and the cylinder.
On the la463 the lift height is 88.6 and digging depth is 5.9. Total travel of 94.5". Cylinder travel is 18.7". Divided out is about 20%. Or a 5:1 Ratio.

Every inch that the cylinder moves is 5" at the bucket. And every 5lbs lift force at the cylinder is 1lb at the bucket.

When I did lo long version by measuring everything I came up with about 21%

The only way I can explain the difference is either minute measurement errors that multiplied over the formulas and rounding off #'s....or because as the loader raises, so does the geometry and My measurements were taken with the loader on the ground.

The cylinder to bucket travel is the method I will use from now on as it gives an effective average over the entire travel of the loader.

 

[Harvest Moon]

Pls. see post#66.
larry

You may get an extra 100psi at full rpm.larry

Sure, but based on LD1's calculations every psi = about 1 lb and I'm only considering adding 150 psi from full throttle readings. I know that may seem insignificant but if I base my setting on what I run the machine at I could end up with more than 200 lbs. of lift while barely skimming by the factory spec. max.

200 lbs is practically a magic number for me because that's probably what I lost with the addition of my loader quick coupler accounting for it's weight and extension of the bucket. It's also significantly over 10% more lift capacity. Of course, I didn't seem to notice the loss of lift with the addition of the quick coupler, so who knows.

Thanks for the input, I'll be working on my maintenance tomorrow, it's all going to come down to my level of inspiration in the morning, or the rain.

 

[J_J]

You would notice a large difference if you went to larger cylinders, but it might not be economical.

 

[johnrex62]

Okay, this mod seems to be well test now since it started a couple years ago. Anyone notice any ill effect over the long term?

 

[Zick]

Granted mines not an L3400 but I bumped up the PSI by about ~200-300 about 2 years ago and have not had any issues with it.

 

[LD1]

Okay, this mod seems to be well test now since it started a couple years ago. Anyone notice any ill effect over the long term?

No trouble out of mine yet. I am running around 2700psi and do a lot of hard loader work.

Since you have a 3700 I assume you may still be under warrenty and might not want to mess with it just yet. But you may want to at least put a guage on it and if it below spec, have your dealer bring it up to spec.

 

[mjfox6]

Moved a bunch of wet clay last weekend. The loader lifted bucketfulls without a problem, even though the rearend was getting a little light (loaded tires and a heavy duty rotary cutter as counter weight). I'm super happy.

 

[johnrex62]

No trouble out of mine yet. I am running around 2700psi and do a lot of hard loader work.

Since you have a 3700 I assume you may still be under warrenty and might not want to mess with it just yet. But you may want to at least put a guage on it and if it below spec, have your dealer bring it up to spec.

Yes on the warranty, was delivered a couple weeks ago and only have 6 hours on it so far, so still plenty of warranty left. :laughing:

As to the dealer "bringing it up to spec", the manual only lists a maximum pressure, not a minimum. How would I argue it is NOT up to spec as long as it is reasonably close to 2-2.3k? It seems a dealer might be a bit resistant to increasing pressure if there is not a definitive underpressure situation. I am also not sure it is something that I need/should do yet.

I haven't had any really tuff loader work yet and am still learning how to use it since this is my first tractor, but this appears to be simple enough to do that if I do develop a "power deficiency syndrome" I would like to know the risks I assume if I follow suit.

 

[J_J]

I think I would leave the system as is if it is performing OK. If something happened, and you have to take it to a dealer, and he fixes the problem, and sees that you have messed with the pressure, it might void the warranty on the broken part, and to further provide warranty, he will probably adjust it back to the factory settings. A pressure gage installed in the system now, will help you with how the hyd system is performing. Your owners manual should tell yo what the normal pressure should be.

Using a 2 in cyl with a 1 in rod, a 100 psi change, will cause you to gain or lose about 314 lbs of force. Two cyl will double that.