Smart Winch

[Rupe]

If you use the visor it is a one man job. Make a kerf cut and sit the visor in, walk around attach the ratchet and away you go!

 

Its not really an issue that needs resolving. Just use two blokes to set it up. I have the visor but have only used it once.

[Dean Lofthouse]

I think that if new product are to be brought out they should be radically different.

 

One area that can be improved upon is the contact area of the rope to the bollard.

 

Rope laying across a flat surface has very little surface area of the rope in contact with the bollard (something like 20-30%) which makes it less efficient.

 

If you could get more surface area in contact, you would be spreading out the heat dissappation and stresses on the rope.

 

In effect, by doubling the surface area of the rope in contact with the bollard, you could reduce the size of the whole device, increasing contact surface area is quite simple

[Rupe]

So you could rund the rope through a channel?? So that more of it is in contact? I see where your coming from but if the rope jumps out of the channel then it would make things worse.

 

All you need is large diameter bollards, but the problem if you get too big is that the difference between 2 wraps and 3 wraps is too great. On some half a wrap is possible, on the GRCS a half wrap is not ideal because the pigs tail fairlead is only on one side.

 

We found that good gloves make up the difference in half a wrap. So you have one wrap, then one wrap plus use the gloves for extra friction, then two wraps, then two wraps plus gloves etc. (of course gloves are worn all the time) .

 

However you do it the heat dissipation and stresses on the rope are not really a factor, they would only occur if you dont have enough wraps. As long as you have the right amount of wraps for the job in hand then there is very little stress on anything, and the rope will twist and come through differently on every lower, so it wears evenly.

[Dean Lofthouse]

So you could rund the rope through a channel??.

 

Exactly Rupe, or even a straight tube that is in two pieces and clamps the rope.

 

Heat dissapation isn't a major factor as you say, but the rope would have a huge amount less acting on it if it had more surface area to spread the friction over.

 

If it were possible, hypathectically speaking, you would only require a fifth of a wrap instead of a full wrap or it could be run through a 2" tube instead of 10" round a bollard

[Rupe]

I know where your coming from but the rope does already have plenty of suface are in use to spread the friction over (if not then the load would fall uncontrollably) but that surface area is spread along a lenght of the rope, so 2 wraps of a 10inch diameter bollard would equal 20 inches.

 

So if your correct that only 20-30% of the rope is on contact along that 20 inches then that mean that any heat generated can dissipate through the other 70-80% of the rope at the same point.

 

Tryign to cram all that friction into a shorter length of rope would mean that there is no where left for any heat to dissipate to, so you have the same friction in, say a fifth of the amount of rope (4 inches) but no where left for any heat to go to, thus heatign the rope up even more and doing more (potential) damage all in one concentrated place.

 

Using lots of rope is actually a good thing as that is what dissipates heat and energy the best, so larger bollards are better than smaller ones.

[Rupe]

If you had a system that uses 5% of rope surface but needed 80inches of rope to get the same friction then your ropes would last even longer.

[Dean Lofthouse]

True and this is only my theory, but I would say it is the first half wrap that takes the vast majority of the hammer, the rest takes very little.

 

So can we make that first half wrap more efficient ?

 

Heat dissapation would be a problem and would have to involve cooling fins inside the bollard or outside the tube ?

[Rupe]

I agree the first wrap does take more "hammer" and less at it goes along to the last bit of the last wrap, but doesn't that mean the first wrap should be made less efficient so that the rest have some more work to do?

 

In the states they have been know to put blue gel freezer packs inside the bollards of some devices, I have never needed to so that makes me think I am no where near the limits of my GRCS.

[Dean Lofthouse]

You could put it that way if you dont mind big bollards

[Rupe]

I think what we have on the market already is fine, Reg's ones filled the gap nicley between porties and the Hobbs. There aren't really any gaps left to fill.

 

There was an ingenious design a few years ago that allowed 2 ropes at once and instead of a central bollard it had four fixed wheels (like pullies but not rotating) all on a plate that was perpendiclur to the tree and hinged so it would follow the user around. You could wrap the rope in many ways around the four wheels to get the friction you needed. So you could go all the way round the outside of all four, or just use one or two, or figure 8 it through two opposite wheels etc etc, endless combinations.

 

There were gaps of a few inches between each wheel so this meant a lot or rope was used and the gaps between each section of friction placed on the rope meant that any heat dissipated even betterer. The device had two sides (each "wheel" was a double) and so either side could be used or both at once.

 

I'm not sure it ever went into production, I only ever saw a CAD picture of it, but it certainly was the most "outside of the box" design I have seen so far.