Building an FEL quick attach for an L3400 Kubota

[Chilly807]

Sean, are those bushings 1" exactly or are they clearance (ie:1.005"). Im thinking about making a bucket and those bushings could save me a bit of work (and money at the machine shop) if they are clearanced for a 1" pin.

Good question, I didn't measure them since mine were already made. They are meant for a 1" shaft, so they are probably slightly oversize. I may pick up a couple next time I'm in, I'll need some for the bale spear frame anyway. If I do I'll let you know what size they are.

Sean

 

[Scooby074]

Thanks. Ill likely check them out myself next time im in too. Probably grab a couple regardless.

 

[Midniteoyl]

I have longer pins, they will extend all the way through so it shouldn't be a problem. I'm going to try to put grease fittings in the lower pins, the rear set will be the stock Kubota pins so it's no problem to grease them.

The material I used to make the pins seems to be pretty tough, it'll be a treat trying to drill them..

I found these collars today at Princess Auto, 1" ID and fairly thick wall, they're meant to be used as a retaining collar on shafting. I think they'd work just fine as the short bushings for the QA. The price is right too, I thing if I'd found them first I would have used them for the 8 small bushings instead of parting and reaming the DOM tubing.

Sean

View attachment 320886

Wait.. You guys have a place called Princess Auto? :duh::rotfl::rotfl::rotfl::rotfl:

 

[Chilly807]

A little more progress in the past week. I have other irons in the fire at the moment, so this is turning into a long term project.



I used a 1/16" shim between the loader side plates and the bucket part of the adapter, to give me enough clearance for everything to move freely. One of the other guys used washers, I think. Either will work, I was worried about distorting the plates and wanted as much surface contact as I could get. The small half-moon cutouts to give clearance for the cross bar weren't entirely necessary after all. I had to move the front half of the adapter further forward to allow room for the weld between the ears of the bucket and the back half of the adapter. If I hadn't, I would have had to either grind the weld back or trim the back of the bucket ears. Neither appealed to me.

I welded alternate sides of the plates in 1 to 2 inch stitches to keep from putting too much heat into the steel. As it was, each time I welded one side the pins would bind hard, only to loosen again once I welded the other side! This continued until the final weld was done.. One pin binds slightly now, but nothing I can't easily fix. The right side is finished except for stiffeners and bracing.



With the first side plate welded in place, I slid the pins in place to locate the second side plate and clamped everything up as tightly as I could for welding. You can see the shim in place in this picture under the side plate. The plates did bow slightly from the heat, but not enough to cause real problems. I hope.



Fully dumped position. I need to weld in some stops to protect the cylinder rod, I may wait until I have the bucket attached to be sure where to put them.



Fully curled position.

Sean

 

[Xfaxman]

....................................

Fully dumped position. I need to weld in some stops to protect the cylinder rod, I may wait until I have the bucket attached to be sure where to put them.

...............Sean

Looking good! :thumbsup:

I am not sure where you could put a stop that would take the full extend pressure without bending something.

If the cylinder touches the arm at point A, it could bend the rod. Right click this picture to open in new tab.

I would measure the clearance at point B, remove the adapter, put the bucket back on, fully dump, and measure the clearance at point B on each side. Then grind the end of the arm just under the rod to get the same clearance.
That is an area that won't weaken the arm.

I think your center to center distance from C to D is a little shorter than the holes in the bucket.

 

[LD1]

Is that actually fully extended? or did you just stop their so you dont bend anything??

I agree that you could either grind a little off the arm, or put the bucket on to see how things fall and where the best place is to put a stop.

On second thought, nix the grinding idea. You really need a positive stop so you dont blow the front of the cylinder out.

 

[Xfaxman]

Is that actually fully extended? or did you just stop their so you dont bend anything??

I agree that you could either grind a little off the arm, or put the bucket on to see how things fall and where the best place is to put a stop.

On second thought, nix the grinding idea. You really need a positive stop so you dont blow the front of the cylinder out.

I don't understand that statement. With the bucket on the front of the cylinder is the stop. The cylinders are made to handle the pressure.

 

[LD1]

I don't understand that statement. With the bucket on the front of the cylinder is the stop. The cylinders are made to handle the pressure.

But most compact tractors are set up so the rod dont actually "fully" extend. Leaving a small bit of hydraulic oil for a cushion. Just incase dumping too fast with a heavy load, or dumping all the way and putting the bucket down to scrape, very easy to damage the cylinder without that cushion.

Look in the pic you edited. Just behind (to the left) of pin C you will see the mechanical stops for the old setup

 

[LD1]

I can tell from experience that the stops are a must have. I have hit mine pretty hard several times (the mechanical stops that is). Some intentional, some not. The cylinder isnt designed to handle that abuse.

some examples other than what I already said...

Dumping a load of whatever while driving to spread it out. Mis judge the distance from bucket edge to ground...bam..hit the stops....NOT intentional

I intentionally do it when trying to free stuck mud or whatever when dumping. A couple of quick hits. But it would add up over time if that was the cylinder

 

[Xfaxman]

But most compact tractors are set up so the rod dont actually "fully" extend. Leaving a small bit of hydraulic oil for a cushion. Just incase dumping too fast with a heavy load, or dumping all the way and putting the bucket down to scrape, very easy to damage the cylinder without that cushion.

Look in the pic you edited. Just behind (to the left) of pin C you will see the mechanical stops for the old setup

Okay, that stop may be to keep the cylinder from touching point A and bending the rod.

 

[bandaidmd]

"Look in the pic you edited. Just behind (to the left) of pin C you will see the mechanical stops for the old setup"

totally agree, it should be easy to add a piece to your bracket that would contact the original stop.

Great job, enjoy seeing other folks projects.

 

[LD1]

Okay, that stop may be to keep the cylinder from touching point A and bending the rod.

AND so you dont bust the front off the cylinder...

 

[bandaidmd]

For those wondering why a stop is used remember that the piston of a Hyd. cyl is only held in with a snap ring.

 

[Chilly807]

Yeah.. the stops are intended to prevent the rod from touching the loader arm. There is more travel available in the cylinder, but overtravel is limited by the mechanical stops welded to the loader arm. I'm going on the conservative side, and intend to leave a little bit more clearance between the loader arm and the rod than was originally provided.

It's tricky moving it now, the left side cylinder only moves when the right side has reached the end of it's travel, so the side that IS moving goes twice as fast. This is why the cross bar is needed, to keep everything in sync with no implement attached.

The holes C and D are slightly upward offset from the originals to keep the loader geometry the same with the bucket pushed ahead 3 inches. The spacing is the same, it's an optical illusion.

Sean

 

[Xfaxman]

AND so you dont bust the front off the cylinder...

What keeps the lift cylinders from busting the front off? I have never seen a lift arm stop. The last three FEL's that I have owned did not have a bucket stop. The cylinder is weakest as far as bending the rod, when fully extended, maybe the stop allows them to use a cheaper cylinder, with a smaller rod diameter.

A cylinder can have an internal stop collar to make it stronger fully extended, but that shortens the stroke.


It can also have a internal cushion system.

For those wondering why a stop is used remember that the piston of a Hyd. cyl is only held in with a snap ring.

All of the ones I have worked on have a nut on the end of the rod. Like these:

 

[bandaidmd]

The 4 that i rebuilt were Kubota and they were snap ring style.

 

[LD1]

The lift cylinders dont get to full extend often. And when they do, it is under hydraulic pressure only. No outside influences are able to act to add MORE force or speed UP how fast the loader raises, like there is with the dump function

 

[600rider]

If the pivot hole and the cylinder hole on your bracket are the same exact distance apart as the holes on the bucket you will not have a problem as Kubota has already done the engineering so you don't have too! They have to be the same or else you could have a problem! Also I noticed that in your full dump picture that you can look through the hole in the side plate and see your cylinder rod. If that hole is for a tie rode to connect both sides of your QH when it is dumped you will wreck your cylinder rod or the connecting rod! You should reevaluate that hole and adjust it accordingly so it wont ruin anything.

 

[dondc]

Subscribed for future reference

 

[LD1]

If the pivot hole and the cylinder hole on your bracket are the same exact distance apart as the holes on the bucket you will not have a problem as Kubota has already done the engineering so you don't have too! They have to be the same or else you could have a problem! Also I noticed that in your full dump picture that you can look through the hole in the side plate and see your cylinder rod. If that hole is for a tie rode to connect both sides of your QH when it is dumped you will wreck your cylinder rod or the connecting rod! You should reevaluate that hole and adjust it accordingly so it wont ruin anything.