Warn aluminum fairleads

[mrblaine]

If you run one, keep an eye on it. Had an incident recently where a Warn line parted on a reasonably hard pull when it shouldn't have. My concern was I did the install and while not probable, it was possible that I missed a sharp edge too close to the fairlead opening. We replicated the pull trying to see if we screwed up at all. At no point could I wind the line on to bring it close to touching a sharp edge.

Stacked up on one side to the point it was dragging on the winch mount. You can see the fiber from the line on the edge, but we can't make it do that.

If you go the other way and pull out more line so the drum diameter is smaller, it still clears the opening very easily.
What we did find was a massive build up of abraded/smeared/melted fiber in the corner of the fairlead.
There is enough that under a hard pull, that could compromise the line and cause it to part under load. Both sides were like this.

That build up is from just being rubbed against the fairlead. There is no edge on the inside close enough to the opening to start that abrasion.
There was some confusion over the angle of the pull. This shows part of how sharp it was.

The line doesn't contact this area unless it is close to or at 90 degrees to the front of the rig.

I'm somewhat baffled, I see the fibers on the edge, I can NOT figure out how to make that happen.

 

[sab]

Looking at that, it looks like what would happen if the winch was spooled line-over-the-top instead of under the bottom. Is it possible that somehow the line doubled-back under slack, and somehow the out button was inadvertently used to continue the pull? If the line got that hot, it may have stuck to the fairlead, and if tension was let up, one of the outer wraps could have grabbed it since it was close, and maybe the winch operator didn’t notice the wrong button was pulling in? I know, seems far-fetched, but it’s the only think I can think of…

 

[mrblaine]

Looking at that, it looks like what would happen if the winch was spooled line-over-the-top instead of under the bottom. Is it possible that somehow the line doubled-back under slack, and somehow the out button was inadvertently used to continue the pull? If the line got that hot, it may have stuck to the fairlead, and if tension was let up, one of the outer wraps could have grabbed it since it was close, and maybe the winch operator didn’t notice the wrong button was pulling in? I know, seems far-fetched, but it’s the only think I can think of…

We see lots of that melted fiber build up on all that type fairlead from Warn. My best guess is the radius is too large and that builds up too much heat which melts the fiber. What you describe is possible, that isn't how the pull was explained to me though.

 

[macleanflood]

My cheap ass Amazon "black" fairlead did something similar to the Amazon pink not red Barbie Jeep rope. I've since retired both to the dump trailer for garbage retrieval and am having fantastic luck using the snot out of my Wizard Recovery Gear.

Here's recovering a Chevy Blazer from the woods...we used a lot of rings on this one...they got quite hot...

-Mac

 

[Badgerbiter]

Interesting footage. You have a lot of experience based on your choice of hobby/interest. I would suggest that you are an expert in retrieval. Great choice to wear a helmet. Your assistant should do the same!

 

[macleanflood]

I would suggest that you are an expert in retrieval.

Not even close. Just flailing around until we break something or succeed.

Thanks though!

-Mac

 

[freedom_in_4low]

Dang it lol. My cousin gave me one of these and I put it on because it looked higher quality than the Smittybilt, and I figured big radius better than small when it comes to rope strength.

The overall amount of heat generated should be the same but maybe the extended contact with the fairlead doesn't let the heat dissipate quickly enough. I'll for sure be keeping an eye on it, especially if I do any high-angle pulls.

 

[TerryD]

I'll have a look at mine when I get a moment.

Do you think the initial deposit was from pulling the cable tight to the recovery point for stowing the hook?

 

[sab]

The overall amount of heat generated should be the same...

I'm not so sure about that. Thinking in extremes, consider two pulls, identical in every way, except one of them is around a 1" diameter post and the other a 3' diameter post (both are infinitely strong for this example). The normal force on the surface of the post is what generates the heat. This normal force develops from zero at the initial point of contact (in the rope travel direction), reaches a maximum value at the midpoint, and then drops to zero again at the final contact point. With the rope traveling at the same speed for both pulls, the area under the normal force vs. time curve is much greater for the larger post. Since this area is directly related to the heat generated, the 3' diameter post will create much more heat:

I gave this a considerable amount of thought when Mr. Blaine first posted it.. Did I misunderstand you, or am I missing something?

 

[mrblaine]

Dang it lol. My cousin gave me one of these and I put it on because it looked higher quality than the Smittybilt, and I figured big radius better than small when it comes to rope strength.

The overall amount of heat generated should be the same but maybe the extended contact with the fairlead doesn't let the heat dissipate quickly enough. I'll for sure be keeping an eye on it, especially if I do any high-angle pulls.

We don't know if the heat is doing it or what. Initially, due to seeing this problem with all that style Warn product, I guessed that perhaps it being a polished cast item that there was a smoothness issue at the microscopic level. It is rare that castings are less porous than a billet of the same material. Then someone well versed in recovery that I trust suggested that perhaps the large radius is responsible.

Maybe some combination of factors is in play. Microscopic porosity abrades the fiber under high load which gets caught in the pores, that puts down a layer of line, the line rubs against that which generates a lot more heat than just wearing against the aluminum, that compounds until you see what is in the pics. No idea really except we see this a lot with this particular fairlead.

 

[sab]

Do you think the initial deposit was from pulling the cable tight to the recovery point for stowing the hook?

I don't see how that would generate any heat to melt the rope.

 

[mrblaine]

I'll have a look at mine when I get a moment.

Do you think the initial deposit was from pulling the cable tight to the recovery point for stowing the hook?

No, I say that based on seeing a bunch of them with little useage and they are fine. This issue almost always starts in a corner though.

 

[mrblaine]

I don't see how that would generate any heat to melt the rope.

I'm starting to think this is a plastic on plastic issue.

 

[freedom_in_4low]

I'm not so sure about that. Thinking in extremes, consider two pulls, identical in every way, except one of them is around a 1" diameter post and the other a 3' diameter post (both are infinitely strong for this example). The normal force on the surface of the post is what generates the heat. This normal force develops from zero at the initial point of contact (in the rope travel direction), reaches a maximum value at the midpoint, and then drops to zero again at the final contact point. With the rope traveling at the same speed for both pulls, the area under the normal force vs. time curve is much greater for the larger post. Since this area is directly related to the heat generated, the 3' diameter post will create much more heat:

View attachment 552207

I gave this a considerable amount of thought when Mr. Blaine first posted it.. Did I misunderstand you, or am I missing something?

You put more thought into it than I did, like actually putting numbers to it. I assumed, possibly incorrectly, that the friction force for dragging two blocks of equal mass but with different areas of ground contact would be the same, (or said another way, i pictured your drawing where the wider curve had a lower peak due to being spread out on the larger contact area, approximately equalizing the areas under the curve) but I'm less confident in that assumption than I was right after I woke up, especially with you (specifically) taking a position to the contrary.

From there the heat is just the extra work done by the winch motor to overcome that friction W=F*d, but if the F isn't the same then the W won't be.

 

[NashvilleTJ]

I'm not so sure about that. Thinking in extremes, consider two pulls, identical in every way, except one of them is around a 1" diameter post and the other a 3' diameter post (both are infinitely strong for this example). The normal force on the surface of the post is what generates the heat. This normal force develops from zero at the initial point of contact (in the rope travel direction), reaches a maximum value at the midpoint, and then drops to zero again at the final contact point. With the rope traveling at the same speed for both pulls, the area under the normal force vs. time curve is much greater for the larger post. Since this area is directly related to the heat generated, the 3' diameter post will create much more heat:

View attachment 552207

I gave this a considerable amount of thought when Mr. Blaine first posted it.. Did I misunderstand you, or am I missing something?

I usually think of myself as a pretty smart guy - until Scott gets out his pencil…



Interesting thread.

 

[srimes]

We see lots of that melted fiber build up on all that type fairlead from Warn. My best guess is the radius is too large and that builds up too much heat which melts the fiber. What you describe is possible, that isn't how the pull was explained to me though.

I"m really skeptical of the "radius to large" idea. I've never seen anything concerning a maximum radius but tons on minimums. The fairlead radius is much smaller than a recovery ring so if that's all it was you could expect a lot of failures with those.

Maybe the fairlead got too hot for the dyneema? You said it was a fairly hard pull, was it a long one too?

If I was going to try an overheat a fairlead I'd focus on a corner like that. Maybe set up a thermocouple and see how hot you can get it?

 

[macleanflood]

Maybe set up a thermocouple and see how hot you can get it?

I've got an IR thermometer. I'll bring it on our next recovery and see it I can get temperatures on fairleads, rings and rope.

Wish I had an IR camera.

-Mac

 

[sab]

We don't know if the heat is doing it or what. Initially, due to seeing this problem with all that style Warn product, I guessed that perhaps it being a polished cast item that there was a smoothness issue at the microscopic level. It is rare that castings are less porous than a billet of the same material. Then someone well versed in recovery that I trust suggested that perhaps the large radius is responsible.

Maybe some combination of factors is in play. Microscopic porosity abrades the fiber under high load which gets caught in the pores, that puts down a layer of line, the line rubs against that which generates a lot more heat than just wearing against the aluminum, that compounds until you see what is in the pics. No idea really except we see this a lot with this particular fairlead.

I like this theory. The porosity of the casting definitely results in a rougher surface, which would put down more plastic. Then, the larger radius creates more heat. Combined, the two effects are substantial...

 

[macleanflood]

Scanning electron microscope anyone?

-Mac

 

[mrblaine]

I like this theory. The porosity of the casting definitely results in a rougher surface, which would put down more plastic. Then, the larger radius creates more heat. Combined, the two effects are substantial...

My plastic on plastic, (polymer against polymer) is based on the same effect being seen on the powdercoat on the winch hoop. The line came into contact with the hoop and left a layer of "melted" line behind.