Setup for reverse winching

[mudhog55]

FYI. back in the early 80s I welded a hitch receiver on the front of my after-market bumper and mounted my winch on a hitch. That way I could use it on the front or back bumper as needed. I ran a cable underneath along the frame and had one-hole crimped type cable connections. My battery had wing nut type post (like boats use) so I just slapped the winch leads on when needed or in the back I just bolted the two cables together. I was clearing land by myself, and that winch got me out several times and 90% I used it on the back. I should have patent the winch mounting on the hitch before Warn started making them. I carried the winch in the back with pullies, 100' of extra steel cable (coiled up in old motorcycle tire) and 2 trailer screw in anchors that comes in handy when you have no anchor points like at the beach.

 

[Wingback73]

Anyone seen this video?

d-

 

[DeltaNu1142]

As I am typing this, it came to me that simply mounting the pulley to the bumper might even be easier.

I like that better, FWIW. With the loosely-tightened bolt and pin idea, I was imagining the racket that thing would make bouncing around on the front bumper.

Another idea might be two appropriately-sized pins and two holes in the bumper. The pulley & pins go into a small bag along with your recovery gear, and you install it only when you need it. Though... then you miss out on explaining your setup when some passerby goes, "what the hell is that for?"

 

[jjvw]

How much is the strength of the rope reduced with all these redirects?

 

[Wingback73]

How much is the strength of the rope reduced with all these redirects?

The strength of the rope isn't reduced at all, of course, but I don't think that was what you really meant: the force on the rope is doubled every time you apply mechanical advantage.

In a direct pull situation, even a redirected one, you are still only applying the force required to move the vehicle. In the video I posted, the force exerted on the rear of the vehicle is double the amount on the front, and this the reason you go backward (while also going sideways).

Using my winch rating as the maximum theoretical load, there would be 12K # of force on the front of the vehicle and the front redirect. The rear redirect and the rear of the vehicle would experience 24K #. This assumes it takes 12K # of force to move the vehicle. In which case you better have a 24K # line.

The good news is that it rarely takes that much force to move the vehicle...

 

[jjvw]

I think you are answering a question about a rigging setup I didn't ask about

 

[Apparition]

https://www.cmcpro.com/actual-ma-sy...pliable rope,effectiveness of a pulley system.

 

[DuckNut]

I was imagining the racket that thing would make bouncing around on the front bumper.

A magnet would eliminate that issue.

Put a nylon washer under a metal washer under the pulley to create a buffer space so the pulley won't contact the bumper.

 

[Wingback73]

I think you are answering a question about a rigging setup I didn't ask about

Could be - you asked about redirects and there are more in the video I posted than in the other setups, so thought you were referring to that

 

[jjvw]

Could be - you asked about redirects and there are more in the video I posted than in the other setups, so thought you were referring to that

I'm asking about the backwards redirects through multiple fixed rings for a reverse winch pull. There is no mechanical advantage happening and only more friction and stress to the overall rigging. None of it is good.

 

[CMBD]

Anyone seen this video?

d-

I think a little less of Warn being there was a rep there.

 

[Wingback73]

I think a little less of Warn being there was a rep there.

You think less of Warn for working with someone to film a video on how to do something that has a multi-page thread on our forum?

 

[CMBD]

You think less of Warn for working with someone to film a video on how to do something that has a multi-page thread on our forum?

Plenty of multi page threads here that have useless information.

That's a side pull. The winch is trying to drag the truck sideways between the two trees the rope is attached to. The truck is moving sideways and reverse motion is provided by the truck.

Had the the snow not given way and let the truck move to the right, you are putting all of that energy on the stuff that isn't moving. That's all bad. Best case in that scenario is the winch stalls so they just cant keep pulling.

On paper its possible that its actually moving forward winching with the reduced line speed from the "mechanical advantage" in the rear.

 

[Wingback73]

Plenty of multi page threads here that have useless information.

That's a side pull. The winch is trying to drag the truck sideways between the two trees the rope is attached to. The truck is moving sideways and reverse motion is provided by the truck.

Had the the snow not given way and let the truck move to the right, you are putting all of that energy on the stuff that isn't moving. That's all bad. Best case in that scenario is the winch stalls so they just cant keep pulling.

On paper its possible that its actually moving forward winching with the reduced line speed from the "mechanical advantage" in the rear.

I completely agree that there is a sideways component to it. That is true most times you winch, but especially in this case where both trees are misaligned with the vehicle.

The line died is greater from the front since it is a simple redirect, but the force is doubled on the back due to the mechanical advantage applied, so net:net that vehicle is going backward (and sideways) assuming the wheels all have roughly equivalent traction

 

[CMBD]

I completely agree that there is a sideways component to it. That is true most times you winch, but especially in this case where both trees are misaligned with the vehicle.

The line died is greater from the front since it is a simple redirect, but the force is doubled on the back due to the mechanical advantage applied, so net:net that vehicle is going backward (and sideways) assuming the wheels all have roughly equivalent traction

The first two pulleys are doing nothing but changing direction. The only one doing something different is the one in the hitch.

Force may be doubled but the line speed for the most part is cut in half at the pulley in the hitch when rigged like that. That is just how it works and I don't think you understand. It is what it is.

Pulling a vehicle sideways out of a rut that is as deep as the tire is tall is stupid.

 

[Wingback73]

The first two pulleys are doing nothing but changing direction. The only one doing something different is the one in the hitch.

Force may be doubled but the line speed for the most part is cut in half at the pulley in the hitch when rigged like that. That is just how it works and I don't think you understand. It is what it is.

Pulling a vehicle sideways out of a rut that is as deep as the tire is tall is stupid.

Exactly, the first two pulleys are redirects with no change in allowed force (other than directional) and the one at the bumper applies advantage (and directional). You've explained it in terms of line speed, I used force. The point is that line speed is irrelevant; force is what moves objects.

That Jeep is going to go backwards. The line may be moving twice as fast at the front, but it is applying half as much forward force at the winch as rearward force at the back hitch.

There is a whole different discussion to be had about the wisdom of tugging yourself or sideways, but if the other option is to be stuck and walk out, it is good to understand how to get your vehicle to move in the direction of land one can drive out of.

I think your point above is also with repeating - there has to be a sideways component for this to work. If he had picked a tree directly in front and directly behind him he'd simply rip his rear bumper off (or stall his winch).

 

[CMBD]

Reverse motion is being provided by the vehicle here, not winching.

 

[Wingback73]

You thought he'd put the Jeep in drive?

Save the insults - I'm not the one who doesn't understand physics.

 

[CMBD]

No reverse winching going on there Mr. Physics.

I stand with my Christ Almighty.

Im out.

 

[srimes]

How much is the strength of the rope reduced with all these redirects?

Strength reduction is a function of minimum bend radius. The smallest radius is the winch fairlead, so whatever reduction that works out to. Additional bends aren't cumulative.

Additional bends do add friction, which reduces maximum pull from the winch. For hard pulls the idea is to use a snatch block/recovery ring to lessen the load on the winch.