Bent cracked loader arms

[tessiers]

I can get some tomorrow.

 

[Verticaltrx]

I don't have a loader mounted plow blade, don't plan on one any time soon. With that said, I do have many hundreds of hours running tractors with loaders and can tell you that putting side stress on a loader is not good. An angled plow blade puts a lot of side load on the loader arms, something to think about...

 

[RFB]

I have operated a 7.5 power angle FEL (QA) snow blade for thousand of hours. It has 4 springs for trip action and a hydro relief valve. I try to operate it as a sentient being: not recklessly. I never float the blade, I ride the stick just like a cyclic, correcting for contours in the road surface. It is always gravel/dirt roads and snow/ice/rock berms.
No damage to the loader.

 

[vtsnowedin]

I'm still hopeing to hear from people that have actually bent their loader. I'd like to see what gave way first. On my old David Brown the cross brace at the front of the loader was bolted in, not welded and had a bit of play in it. If you dug a lot with one side of the bucket you could rack the arms a couple of inches but just switching sides for a while would rack it back. I tended to favor using the left side as the control levers were on the right frame post and blocked the view.

 

[daugen]

I'm still hopeing to hear from people that have actually bent their loader. I'd like to see what gave way first. On my old David Brown the cross brace at the front of the loader was bolted in, not welded and had a bit of play in it. If you dug a lot with one side of the bucket you could rack the arms a couple of inches but just switching sides for a while would rack it back. I tended to favor using the left side as the control levers were on the right frame post and blocked the view.

sounds like you are trying to avoid a bad experience of the past, but that old loader, well, it sounds "old"... Wonder if you had welded the crossbrace if it would have made any difference. If not, I just hope more modern
FEL's are stronger. I'm just as interested as you are in understanding "fails" here.

Putting a big side load on a bucket should be left to excavators... I don't think our FEL's were built for that. Though within reason, "operating as a sentient being" (great quote) I'm sure we can all do a little of it.
It's when I put a chain on the bucket and go to pull something heavy out of the woods, my understanding is to go "straight back" to avoid side bending.

 

[RFB]

Maybe the concept of a "bent loader arm" is based upon false premises and is thereby more legend than fact. If (for the sake of the argument) most people who frequent this site come either to obtain and/or share knowledge, then that could indicate thoughtfulness rather than recklessness. If that is the case, the cross-sectional sample obtained would not have sufficent idiocy to provide the proper amount of damage desired.

 

[daugen]

Maybe the concept of a "bent loader arm" is based upon false premises and is thereby more legend than fact. If (for the sake of the argument) most people who frequent this site come either to obtain and/or share knowledge, then that could indicate thoughtfulness rather than recklessness. If that is the case, the cross-sectional sample obtained would not have sufficent idiocy to provide the proper amount of damage desired.

Well, in my "prime" I could be an idiot of the first order...

And as the Amish farmers say, every day some farmer puts his foot in the milk bucket...

So I guess I could volunteer to help provide sufficient idiocy...

btw, wonder if anyone in the welding forum has some experience with loaders...they'd be the ones to fix them.

more legend than fact.
The Sasquatch of tractor land...

 

[vtsnowedin]

Good thoughts guys. My old loader was certainly "old" by the time I was done with it:ashamed: but it was pretty well built and not that much different from what is available today. I expect that there are some loaders out there that are not well matched to the machine they are on and can fail under normal use and there may be material choices and manufacturing methods made by the builders that leave some brands less capable over the long haul. Perhaps it is just an old wives tale and it seldom happens without a wreck to finish things off.

 

[RFB]

The Sasquatch of tractor land...

And his third cousin once removed, "front differential damaged by chains on the front tires".

 

[xtn]

how fast can one go pushing a bucket into a gravel pile? 2-3mph?
Always wondered how putting all that force on the bucket hydraulics
worked in the long haul. Seemed to me that the hydraulics would cushion the
impact but clearly bent or cracked arms are a reality.

Seems reasonable to expect any modern well made implement to not crack or bend structurally at full load,
or even something over that. I'd expect movement to stop, but not metal to break.

Now i guess if you run your tractor and loader into a tree at 15 mph, anything goes.
But short of a higher speed collision with something or a tractor upset or rollover, that steel should handle it.
Shouldn't it?

You've kind of touched on some engineering language choices that are interesting.

First, the hydraulic fluid itself isn't going to provide any "cushion" as it is practically incompressible. I mean that's one of the big reasons it's used. Any "cushion" in an FEL system is going to be found in the expansion of lines, the loose tolerance of joints or actual soft bushings used in joints if any, and/or actual give in the metal somewhere.

Now let's talk about full load. Nothing fails below full load. If something failed, it wasn't below full load now was it? And if something hasn't failed, then you haven't yet loaded it past it's full load capability. If something fails at a load below what you THOUGHT it's full load capability ought to be, then you were wrong. Now the figures a manufacturer publishes as his design full load capability is something else altogether. I agree with you that with modern engineering data, tools, and manufacturing techniques, we ought to expect that any published design load figure is safe and ought to not cause undue damage. But then we could talk about expected cycles, allowable tolerance for small defects due to age and use, etc. Like that little scratch that was put into the metal years ago when another operator accidentally dragged the boom along a fence post. And that little scratch has been gently cycled a few thousand times since then. What's the max load capacity of the boom now? LOL impossible to answer accurately from the vague info given, but maybe it's less than it used to be, huh?

And collisions, or let's call them "very high acceleration events", at even low speeds can generate HUGE momentary forces. For example: from 3mph to dead stop in 0.01 seconds... that's over 13 g of acceleration. Now if you've got X lbs of machine behind the loader when you run into a tree, that's 13X lbs of force trying to bend or break something. If my tractor weighs about 5000 lbs, that's 65,000 lbs trying to bend or brake my loader during that 0.01 seconds. Stopping in the same amount of time from 15 mph and you've got yourself a 68 g event.