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Torsional stiffness is one aspect that has to be dealt with on occassion. Racking resistance due to the bucket moving sideways as the tractor encounters bumps is another factor that the crossbar has to deal with on almost every occasion that the tractor moves, with or without a payload.

A 2" diameter circle has 3.14" of weld around the perimeter. A 2" square has 4" of weld.

It's rarely the first time that does damage to a loader. It may do the same operation several hundred, or even several thousand times before damage occurs. The objective is to fabricate a loader that will have zero structural failures under many maximum loads over an extended life.
 

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"The objective is to fabricate a loader that will have zero structural failures under many maximum loads over an extended life."

Tudor should have added, "If used correctly". It is almost impossible to build any machine that will withstand abusive use. So it becomes the aim of the designer to shoot for some compromises such as cost, weight and practicality. Obviously, the material used to build them could be so heavy that small tractors could not use them and the cost would preclude anyone from buying them. As Tudor has mentioned before, all the weight you add to the dead weight of the loader has to be countered by the counterweight. Plus the strain on the front axle/tires goes up for no real benefit.
 

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"The objective is to fabricate a loader that will have zero structural failures under many maximum loads over an extended life."

Tudor should have added, "If used correctly". It is almost impossible to build any machine that will withstand abusive use. So it becomes the aim of the designer to shoot for some compromises such as cost, weight and practicality. Obviously, the material used to build them could be so heavy that small tractors could not use them and the cost would preclude anyone from buying them. As Tudor has mentioned before, all the weight you add to the dead weight of the loader has to be countered by the counterweight. Plus the strain on the front axle/tires goes up for no real benefit.
Not stated on purpose.

Small GT loaders are not designed for super heavy lifting or other such abuse because the tractors are not heavy enough to deal with forces that are that high.

The loader on my MF 1655 has a subframe and front bracing that weighs about 30-40 lb more than what would be considered minimal for any GT. It has lifted and transported payloads as high as 1250 lb using a 250 lb implement on the 3PH for counterweight, and pulled 10" diameter concrete piers out of the ground with the rear wheels in the air and a 385 lb implement on the 3PH plus an additional 80 lb of wheel weights. Permanent ballast, not including wheel weights and 3PH implements, is 400 lb and the tractor, loader, and bucket weigh 2000 lb (scaled weight) in this configuration. The bucket normally on the loader weighs 210 lb with a struck volume of 1/3 cu-yd, or about 800 lb of dirt. With over 2000 hours of brutal service, the subframe and diagonal bracing have had zero structural failures.



I'll point out that subframe and diagonal bracing weight is centered between the axles and does not affect counterweight required.

It doesn't take a whole lot of additional material to make a loader "bullet proof". It just takes the right size of material. The subframe and diagonal bracing is all 1/8" wall structural tubing with only the attachment points and the cross bar supporting the posts being thicker. I used 2x3 for the subframe and 2x4 for the diagonal bracing where 2x2 would have been sufficient for both if slightly lesser loads were involved.
 

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My point on abuse was centered more towards the asymmetrical forces rather than overweight lifting. The guy who plows into an unseen stump with one side of the bucket at traveling speed or the guy who tries to lift too much with only one arm taking the strain. I think that just lifting over the recommended limit is still a symmetrical force and would distribute the load evenly to all parts of the structure. Also, if you overbuild the loader then the weakest link in the chain becomes the tractor frame/axle. It would be better for the loader to give rather than the frame of the tractor. In the manual that I have for the JD 44 it states that the loader should not be used as a battering ram. It is obvious what and why they say that.
 

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I'm not disputing your comments, merely adding to them a bit of the practical. Asymmetrical loading on a GT gets to be very interesting as the payload increases in weight. The usual effect is that the opposite rear tire gets light with the normal accompanying lack of traction. In extreme cases, the tire will come off the ground and the tractor is at risk of toppling due to the pivoting front axle. An operator learns in a hurry just how much asymmetrical loading can be applied, and that is rarely enough to cause issues other than a severe tightening of the sphincter.

It takes many applications of asymmetrical loading to cause issues with a reasonably well installed cross member. I know, because the cross member for my GT's loader is not up to the same standards that I used for the subframe and it has cracked. There is not a boneheaded stunt that I haven't tried with my loaders over the years, and yet they have, for the most part, survived, and I've learned a lot of lessons in the attempts.

As mentioned, it boils down to the weight of the tractor. With absolute maximum ballast, asymmetrical loading may cause damage to the arms in one lift. Maximum ballast for most heavy GTs is approximately 1550-1650 lb. With a 1500 psi relief setting and 2" cylinders, I'd worry more about the effect of the over 4000 lb of weight on the small front tires than bending the arms. The arms can usually be straightened out using the reverse asymmetrical load and a few minutes work with a welder. Blown front tires and bent rims take a bit more time and money.

Anyone who has used a loader for snow removal, has used it for a battering ram when they encounter frost heaved patio stones. This is why the subframe should butt up against the rear axle tube as the closet point of application of force by the rear tires. JD mounts their plows to a harness bolted to the front of the tractor's frame. When the plow meets an immovable obstruction, the resulting forces attempt to jackknife the frame between the plow harness and the driving rear wheels. The same applies to loaders. I, being the granite headed Scotsman that I am, had to learn this particular lesson after the third repeat early on in my FEL experience. The major cutting edge impact force gets transferred back to the rearmost connection of the subframe to the tractor.
 

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As you make it stronger, you add weight; that weight is subtracted from your payload.
My FEL will lift about a ton, but I often want just a little bit more.
I guess that will always be the case.
 

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I have found the JD OEM design for the #40 and the #45 GT loaders to be very sturdy. Have owned both. have hit road curbs clearing snow, lifted oversized loads ( approaching 2000 lbs with the #45) with no flexing, twisting, or breakage!! Would not hesitate to copy the design(s) if building a FEL. have found that the tractor "tilts" on off- center loads before you over-stress the boom & frame.
For years, I've carried 900 lbs of steel plate in the weight box and 500 lbs or liq. ballast in the rear tires for loader work & snow plowing without issue. The operator has to be smart and avoid un-balanced lifts or loads that can over-turn the machine. More than once. I've had the rear wheels 2 ft off the ground and the bucket buried under an immovable object! :tango_face_devil:
 

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Discussion Starter #28
I have one more bucket design question. Any ideas why some buckets have the return on the ends of the bucket rather than just being straight? I see this on some modern Deere designs and lots on bigger buckets on back hoes and dedicated FEL's. My only guess is it allows material to spill off the sides before you have it curled all the way back and dump it on the hood.
 

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Hi Turbo - Nice tractor set up!!! I think your are correct. the material will slide off to the sides before over the back and onto the tractor hood (or operator!) It's probably more of an issue on larger machines that raise the bucket higher? I just installed a 4-in-1 bucket on my x595 - works great - use it a lot processing fire wood!!
 

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Discussion Starter #30
That's not my tractor, just a picture from a CL add to demonstrate the side profile of the bucket I was asking about. Boy, if I had that tractor I wouldn't be messing around welding up my own FEL!
 

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Bucket volume is measured as "struck", as in laying a straight edge from the cutting edge to the top of the bucket and striking off all material that doesn't fit under the straight edge. The volume will be considerably less without the return at the top of the bucket, and the return offers a secure location for hooks or lugs to lift odd shaped objects that don't fit in the bucket.

In the case of the bucket in your picture, the straight edge would be applied from side to side because of the added length of return at the top. Normally, the leading edges of the side plates are straight from the cutting edge to the front of the return for maximum strength at the top for chain lifts.

The front edge of the return is usually about halfway between the cutting edge and the back of the bucket when the bucket is flat on the ground.
 

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building your own can be fun , and frustrating, parts are so expensive. just the valves, fittings & hoses cost a bunch. I spent close to $500 for misc. parts to hook-up the 4-in-1 bucket on my x595. That doesn't include the cost and shipping for the bucket itself!! in the case of your 425 - you probably can't find a used No. 40 loader to fit it? JD hasn't made that loader in many years. I don't think they sold to many of them either, so the used inventory is small too. they were a little pricey. they retailed for over $3,000!!!! It will be well worth it - an FEL is so useful, you will find uses you never considered!!
 

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Discussion Starter #33
I had the seat pan off today and i think I stumbled across a lucky find. Can anyone confirm this is the correct THRV for use with a loader?


It was on my list to buy. I’m kinda psyched that I may have saved almost $200 with the lever and shipping.


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hi turbo - that is the relief valve for the loader, it replaces the check valve that was originally in the pump from the OEM (original check is flat and looks like the check valve to the right of it). that is the POS:tango_face_sad: that is limiting your loader lift capacity. if you go back to the OEM check valve, you can easily double the lift of the loader.:tango_face_wink: You will need the OEM free-wheel lever too. the shaft needs to be straight to open the OEM check valve to release the pressure in the drive so you can push the tractor (free-wheel).
 

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No that THRV does NOT affect the relief pressure for the implements. Only for the hydro drive to the wheels. The relief valve for the implements (like the loader) is the short one in between the other two (directly under the freewheeling lever) that has a flat top. That's the one you want to shim if you need increased relief pressure for the loader, etc. And yes, that is the correct THRV for use with a loader. Looks like you did get lucky. Although not purely necessary, they are a nice bit of insurance if you use a loader a lot. I have only hit the relief on mine a handful of times in 16 years.
 

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Discussion Starter #36
eKretz, Thanks for the confirmation. So it sounds like it will trip if you try to push too hard on something that won't move so you don't blow up the rear end? What does it act like when it releases?
 

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Yep, it prevents spikes in pressure in the hydro circuit. When the relief pressure is reached, the pedal just goes to the floor basically and you can hear a little whine type noise from the hydraulic fluid going through the relief, sort of like the noise the power steering on cars sometimes makes when it's under a high load or low on fluid. The only time I've ever hit the relief was with the loader buried in hard packed ground and pushing forward into the earth while in 4wd. Like I said, only a handful of times. As far as I can tell, there's no real drawback, only benefit.
 

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Discussion Starter #38
I’m making a little progress. I got the subframe tacked and the holes for the cross tube drilled out.



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Wow, what's the capacity on that bucket? Looks like considerably more than my 45 loader's bucket. Nice job on the fab work, it looks great.
 

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Discussion Starter #40
It’s 48” wide and 18” tall, 18” deep. My primary planned uses are snow removal and mulch. It will be a little big for dirt work so I will have to take it easy. It’s pretty close to the 40 bucket but a little deeper on the top.

Next I need to make the diagonal braces to the front and a bunch of welding before the plumbing.
My goal was to use it to spread mulch this year but that may be ambitious based on my lack of progress. That said, I would much rather do fab work on the tractor than manual shovel work!


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