Pretty sure the winch or bolts would experience catastrophic failure before the plate.
CK5
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454Sub
5/8 ton status
The bolts would definitely shear before the plate gives up.
Simplified model of winch/plate mounted similar to yours.
Stress in your 6x3/8" flat bar with 8,000lb load on the centerline of winch. This model pretends the edges of the plate are fixed (as if it were fillet welded into the top of the frame) I know this isn't an exactly accurate but it is a decent representation. A mentor I once had used to tell me often that it is better to be approximately right than exactly wrong
This isn't catastrophic failure but it will bend/yield some.
This is A36 steel, this shows that you will yield and permanently deform your plate if you winch on it this hard (8000 lb straight out the front pull) with it mounted like that. Deformation is exaggerated 7x in this model.
Max deformation in the plate in the loaded condition looks like this:
It will rebound back towards the pre loaded state, but will retain some amount of the deformation. The green color on the front and back edges of the plate are roughly .2" deflection here.
I agree with these guys, frame rails, or the bolts will be the first to go, but not before you bend that plate...
I'll do another one mounted on a receiver tube to show the different case.
454Sub
5/8 ton status
Jesus, I couldn't imagine bending 3/8 plate.
But I don't run a winch, I just assume the good Lord himself gets me through stuff. He seems to have a soft spot for guys who don't have winches and do stupid stuff.
But I don't run a winch, I just assume the good Lord himself gets me through stuff. He seems to have a soft spot for guys who don't have winches and do stupid stuff.
CoolSimplified model of winch/plate mounted similar to yours.
View attachment 248520
Stress in your 6x3/8" flat bar with 8,000lb load on the centerline of winch. This model pretends the edges of the plate are fixed (as if it were fillet welded into the top of the frame) I know this isn't an exactly accurate but it is a decent representation. A mentor I once had used to tell me often that it is better to be approximately right than exactly wrong
This isn't catastrophic failure but it will bend/yield some.
View attachment 248519
This is A36 steel, this shows that you will yield and permanently deform your plate if you winch on it this hard (8000 lb straight out the front pull) with it mounted like that. Deformation is exaggerated 7x in this model.
Max deformation in the plate in the loaded condition looks like this:
View attachment 248518
It will rebound back towards the pre loaded state, but will retain some amount of the deformation. The green color on the front and back edges of the plate are roughly .2" deflection here.
I agree with these guys, frame rails, or the bolts will be the first to go, but not before you bend that plate...
I'll do another one mounted on a receiver tube to show the different case.
Maybe He likes to watch
Here's another simplified analysis of a winch mounted on a receiver tube this way. Same 8,000lb load straight out from the centerline of the winch.
Here's the stress distribution.
Highest stress by far is in the receiver tube where the pin goes through. Mounted like this will likely survive much abuse.
Here's the displacement model:
Would be concerned about the plate to tube mounting more on the receiver model. Plate would need to be welded underneath as well
As a point of reference, mine also has a 3/8” plate across the front of the frame essentially creating a wedge with 6 points of contact with the winch
As a point of reference, mine also has a 3/8” plate across the front of the frame essentially creating a wedge with 6 points of contact with the winch
Yeah that simplified model just assumes the tube and plate are part of a solid body, not two pieces welded together. Those welds would see some pretty high forces. A full load pull would test them for sure. a couple of 6" long 3/8" flare bevel welds can hold a shit ton of force.
Is your other plate vertical, or angled across the bottom of the frame rails like a skid plate? Is it tied into the other plate? I don't know how likely it is you would ever really pull that hard on this anyways, If you hung the truck from the winch line and pulled it straight up in the air it couldn't pull that hard. Sunk in the mud, who knows I guess?
Please don't think I'm bagging on your install at all. Not the case. I just have access to some pretty cool software and thought it would be interesting to see/show. I'm going to mount mine very similarly. I love that you shared so much detail on your build. I have learned/gotten a lot out of it. Your truck just simply kicks ass, one of my absolute favorites on here.
Let me know if you'd like to see something else modeled and I'll give it a shot. I'll stop cluttering up your thread now.
No not at all, it’s good to have a valid point of consideration on things like this
My plates are not tied together, and it is mounted like a skid at an angle. Some reinforcements but not perfect by any means
I just looked at my plate today and realized that I gussetted the plate in front and back. My Chinese winch will likely be the thing to die first
Aren't most off the shelf winch plates, actually a tray with flanges bent up or down? I have a K5 with some thick strap welded to the edge of the plate to do the same thing. ...
Cool to see that software stuff!!!
Cool to see that software stuff!!!
You don't think you can bend plate, but given enough pulling power it will move some stuff around. The winch mounting on one of our wreckers here has been pulled hard causing the mounting for the fairlead down. The winch is a 15,000 pound hydraulic Ramsey.
Yes that one got reefed on. That's exactly how the stressed parts look and that one is tied in really really well and it still bent.You don't think you can bend plate, but given enough pulling power it will move some stuff around. The winch mounting on one of our wreckers here has been pulled hard causing the mounting for the fairlead down. The winch is a 15,000 pound hydraulic Ramsey.
If you do, feel free to put a link here to the new thread
Where did you get the rear output flange on your NP205?
ORD sells the flange
