Tried out my new winch today (Runva EWP12000 24V)

[Fred_M1010]

I tested the pulling force of my new winch today
And I must say I'm pretty baffled at the result...

I anchored the truck to a tree and hooked the cable to a scale attached to my tractor.
(Yeah, I swapped the John Deere for a Fendt a while back)

The scale didn't go higher than 2500kg, so I put the winch in high gear so I wouldn't bottom out the scale.
It almost bottomed out anyway, I got 2100kg (~4620lbs)

But since I know the gear ratio of the winch, I can calculate how much it would pull in low gear.

High gear has a 35:1 ratio, and the low gear has a 256:1 ratio,
So in low gear it should pull 4620*(256/35)= 33792lbs

When I was done measuring I placed it in low gear and removed the scale
Then I was able to pull the tractor with the brakes on

Ok, it was a little snow on the ground, but it wasn't very slippery.

And here's the evidence

Has anyone here tested the pulling force of their winches?
I'm a little curious about what's normal...

 

[manchildau65]

Just remember that the rating of the winch is based of the weakest link... Also b/c it has the potential for a "life or death" situation, engineers typically throw a factor of safety of 2 or higher when they are setting the advertised specs (I use three when designing... I think aircrafts are like 5!)

 

[manchildau65]

Dang, low gear is really low gear isn't it! Always liked reading/watching your posts... I can't even imagine how much harder you're going to push it now! Well done.

 

[Fordum]

Never tested any of mine. When I was building my last truck bumper setup, I wanted to put a strain gauge in the mix so I could see how hard it was pulling, but never got around to it.

Back when I used to help build winches, we tested each one by mounting it on a big mount, hook a big battery to it, and see if it would break a 5/16 steel core cable. If it did, we sold it.

My hydraulic PTO is set so that it will go into bypass before it breaks a 3/8 steel core cable on the first (outside) wrap.

One layer farther down, it will break the cable.
Its rated at 12,000lbs.

Once, a few years ago, I had a situation where I had to do some serious pulling, so I borrowed a length of 1/2 cable and replaced my 3/8.
Later, I called tech support and asked if I might have damaged my winch.
I figured I had gone above 12,000.

They assured me that a one time pull like that would be OK. They said that above the 12,000 mark, I was in the safety cushion. They said that all their winches had been tested to double the rating.

There was no danger of anything breaking up to 24,000. However, lots of use in that range would cause accelerated wear of the brass gear and the shaft bushings.

On yours, don't forget the more gears, the more friction. Odds are the low range will not increase mathematically like that.

Plus, the more load, the more friction on the bearings.
The shaft almost certainly uses sleeve bearings, and their friction increases rapidly with load.

 

[Fred_M1010]

Back when I used to help build winches, we tested each one by mounting it on a big mount, hook a big battery to it, and see if it would break a 5/16 steel core cable. If it did, we sold it.

Haha, thats a great test

I think I'll use the snatchblock next time I pull the tractor, just in case

 

[shoudabinacowboy]

Just remember that the rating of the winch is based of the weakest link... Also b/c it has the potential for a "life or death" situation, engineers typically throw a factor of safety of 2 or higher when they are setting the advertised specs (I use three when designing... I think aircrafts are like 5!)

I think there is actually a lower safety factor for stuff that flies because of the weight. The safety factor for space travel would be as close to 1 as possible because the extra weight costs $$$.