Skidding Winches

[Rustyiron]

Gordon, how important do you think the wider flange on the bottom side of the sheave is?

 

[Gordon Gould]

Gordon, how important do you think the wider flange on the bottom side of the sheave is?

I'm not sure. I think when the hook or slider comes into the groove and jacks the cable out if there is enough downward force on the cable from the log then it should de-rail just like pulling a belt off a pulley or a chain off a sprocket. The small diameter will make it go easier.

Maybe the small diameter is all about controlling the direction of the de-rail to make sure the cable doesn't try to come up over the top of the sheave. The small diameter will roll the hook down when the cable is jacked out of the groove.

Just ideas - dont really know.

gg

 

[Rustyiron]

I fooled with this $25 HF snatch block today while it rained. This is where I'm at right now. Wondering about the de-railing mech.

 

[Jim Timber]

If the hook doesn't have a wider flange to bump it, the edge of the pully will take the hit on both sides. You want the sheave spit free before the hook applies pressure to it.

 

[Gordon Gould]

I fooled with this $25 HF snatch block today while it rained. This is where I'm at right now. Wondering about the de-railing mech.

Looks like if you take the two piece sheave you've made and flop it over so the small diameter is to the outside - away from the half shell, you should be good to go. (Probably your plan)

Just ?? need a finger to hold the cable when it is slack and that will get pushed out when the hook hits it. I see space is tight. Maybe something that folds or pivots down instead of a rotating finger. ???

Looks good to me so far.

 

[Rustyiron]

That sheave (HF) is aluminum and I'm afraid that when the cable rides over the edge when "self releasing", it will damage the sheave. I added that 3/8" plate to protect the edge (during de-railing) and had planned on leaving it in that config.?
I meant to ask, is there an up/down orientation when using your's?

 

[Gordon Gould]

Good morning

Yes - It will only work well or consistently with the open sheave down and the half shell with the connection to a tree up. That is why you need that finger - to hold the cable in place while the line is slack during set-up or if you let off during the pull. That is it's only function.

If you have the cable on top it tends to re-catch on the sheave after release as they fall.

I can see where aluminum would get chewed up pretty quick. But it still allows you to experiment and get something that works.

gg

 

[Rustyiron]

Thanks GG, so far not a big investment. Just have a hard time forking out $250 or so for something with 1 moving (small) part :laughing:

 

[Gordon Gould]

Thanks GG, so far not a big investment. Just have a hard time forking out $250 or so for something with 1 moving (small) part :laughing:

I agree with that. But the thing does weigh 12 lbs w/o the clevis and there is a lot of welding in it. Also a small volume market. It is heavier than I need for my winch but a big winch needs something pretty stout.

Edit: Remember the snatch block can see twice the winch pull force depending on the cable angle.

I was lucky and got mine for half that price. It was one of a group of prototype units that were made by someone and sold off. They probably thought they could get rich with $250 to $300 competition. That was two years ago and it seems they did not follow through with production. At least not under there own name.

gg

 

[motownbrowne]

I was lucky and got mine for half that price. It was one of a group of prototype units that were made by someone and sold off. They probably thought they could get rich with $250 to $300 competition. That was two years ago and it seems they did not follow through with production. At least not under there own name.

gg

Yeah, they're sold by someone else now. I got one of the new versions when they were offering a deep discount to forestry forum members. It's nice, but the bearing is now made in china instead of Europe, and they don't publish a working load limit. And they cost..... You guessed it: $259 (marked down from $289 for fall). Either way, I'm happy with mine for the price I got it for.