Mid mounted winch

[cols110]

G`day all I am interested in fitting an EP9 as a mid mount set up.

The EP9 is supposed to be up to the job for powering in and out, coupled with an external brake it seems to be a pretty good choice, any thoughts on why one would`nt work, seeming it would be under load in both directions depending on which way you are recovering.

I am not really interested in the usual set up running snatch blocks like is done in the Ibexs. When I was at a 4x4 show in Melbourne in October I noticed this mid mount set up on one of the challenge trucks in OZ and liked the concept he has used for cable direction change. He had a dual winch set up, running an electric and PTO whinch, did`nt get a chance to talk to the owner which was a bummer but did get a few photo`s.

I would like to drop the winch in the middle of the rear passenger floor well on my 110 if possible, with regards to the photo`s going rearwards should`nt be to much of a problem, but going forward is where the problems will lie. If I could get away with re-directing the cable via flared tubes as done here, my main concern is that the cable would bunch to one side on retraction without it being fed from the middle or allowed to run onto the drum centrally.

Have a look at the photos and see what you think, is it a viable option?

[Top90]

Looks interesting.

I did run a mid mounted winch for a while on my red 90, it was great for self recovery and saving weight.

The problem is that the drum is not normally easy to get to, if the plasma rope pinches on itself its a real PITA to sort out and quite time consuming so not any good for competitions, hence I've gone back to two winches.

So you would need to make sure it's easy to get to the drum and that you can thread a new rope through if it breaks without getting under the car as you never know where it could go. (mine went it deep soil once with the chassis resting on the ground)

If I was only using the vehicle for general recreation I'd have stuck with it.

Also worth remembering that every time you redirect the rope it will be rubbing on something, so the material may have a shorter life than in normal use.

I used a pulley set exactly lined up with the middle of the drum so bunching was not a problem. Instead it always piled up on the middle and hardly used the outsides, but if you have the clearence this is not a problem, you'll just lose the power a bit due to the large diameter on the drum when doing a short pull.

Richard

[Bush65]

...I would like to drop the winch in the middle of the rear passenger floor well on my 110 if possible, with regards to the photo`s going rearwards should`nt be to much of a problem, but going forward is where the problems will lie. If I could get away with re-directing the cable via flared tubes as done here, my main concern is that the cable would bunch to one side on retraction without it being fed from the middle or allowed to run onto the drum centrally.

Before addressing some of your questions I would like to explain what is called fleet angle.

On cranes for example, the rope is lead from the drum to a sheave. The sheave is aligned with the centre of the drum.

When the rope is coming off the drum, at one of the flanges, the rope makes an angle to the centreline of the drum and sheave. This is the fleet angle. There will be a left fleet angle and a right fleet angle.

The fleet angle is most important for good spooling of the rope onto the drum.

For a high speed, multi layer winch drum, the fleet angle should be approx 1-1/2 degrees. Regardless of what people think of their 4wd winches, they are not the high speed winches that this applies to (think of mine winding for examples of high speed).

For other multi layer winches the fleet angle should be approx 2 degrees.

For any width of drum, there is a distance from the drum to the sheave (or a hawse pipe like you are considering) that will give an acceptable fleet angle.

If the fleet angle is too small, the rope will not spool properly on the drum and will bunch up at the drum flange.

If too large, it will not spool properly out to the flanges and will bunch in the middle.

Wire ropes are normally made right hand lay (the way the rope strands are twisted together to make the rope).

Most of our 4wd winches are underwound (the rope comes off the underside of the drum).

Right hand lay rope, on an underwound winch drum, should be anchored to the right hand drum flange (always face in the direction that the rope runs from the drum when determining left or right side).

For right hand lay rope and an overwound drum, the rope should be anchored on the left drum flange.

Then, when the 1st layer of rope winds on, the tension in the rope, will cause a small amount of twist in the rope due to the lay of the strands. This twist will cause each rope turn to lie snuggly against the previous turn.

For our underwound drum, the 1st layer is wound on from the right flange to the left flange. When the 1st layer is complete, the fleet angle has a component of the rope tension which assists the next layer to start in the opposite direction ie. from the left flange to the right flange (or 2nd and 4th and 6th layers).

Plaited synthetic ropes do not twist like layed ropes, so the anchor side is not relevant, but the fleet angle is important for good spooling with all types of rope.

With a mid mounted winch, which is more difficult to see how the rope is spooling on the drum, it is very important to get the fleet angle right. Once you have a position for the winch and the nearest sheave or hawse fairlead, sorted (for the fleet angle), then you can change the rope angle to other sheaves/fairleads, to route the rope where you want it to go.

The winch does not need to be mounted on the centreline of the vehicle, nor does it need to be square to the centreline of the vehicle. As long as the left and right fleet angles are satisfactory.

Also try to minimise the angle at each of the points (sheaves or fairleads) where the rope direction changes - better for the rope and reduces frictional drag. For mining ropes, unless the rope bends around a large radius, the deflection should be less than 1-1/2 deg (this affects the load distribution across the section of the rope). More flexible ropes, which have smaller outer wire dia relative to the rope dia, can be deflected more at the sheaves/fairleads.

[LR90]

Always amazes me the knowledge available on here.

John,

For our underwound drum, the 1st layer is wound on from the right flange to the left flange. When the 1st layer is complete, the fleet angle has a component of the rope tension which assists the next layer to start in the opposite direction ie. from the left flange to the right flange (or 2nd and 4th and 6th layers).

If I've got this right does that mean the default rope attachment point on my 8274 is at the wrong end of the drum?

[cols110]

OK, thanks Richard, a snatch block leading onto the drum was an option for the front, but I had not considered it bunching in the centre.

This is for general recovery, not challenges, so speed is not a consideration.

John, bloody hell mate, that made my brain strain, thanks for the write up, very interesting, I had to re-read it to let it sink in, so the way I understand it then, is the optimum fleet angle is 2 degrees, so by angling the winch(don`t know if I have the clearance to do this) it would help get this angle, from the rear it would`nt be a problem, but the front would take a bit of thinking, maintaining a 2 degree angle would be quite hard as you could set this up to the middle of the drum, but by the time it got to either side of the drum, the angle would be way out, especially if you could only allow a couple of feet lead onto the drum out of the last hawse.

So as I would be pulling from the lower part of the drum forwards and upper part rearwards(depending on which way the winch was mounted), with plasma this should`nt be a problem due to it not being directionally wound.

Thanks for the write up.

[Turbocharger]

I'd say to keep the angles sensible, when winching forwards the best compromise would be to tuck the winch up as far forward as possible against the bed's "headboard" and run it back to a pulley on the rear crossemember before heading off through your tubes etc to the front of the truck? Otherwise you'll always be working a compromise of front and rear winching.

[cols110]

That might be the only viable way of doing it, have one snatch block at the rear to run the cable forward, and let it spool straight out the back for rearwards use, that way you could maintain a decent angle from the back with the winch as far forward as possible.

[Bush65]

It's not easy to get a good fleet angle in a 4wd vehicle. In some installations where there is restricted room (eg on ships) they have a sheave on a cradle that moves across with the rope, to control the fleet angle. For cranes, they allow maximum 5 deg, but that is for single layer winding and deep rope grooves in the drum (3 deg for smooth drums).

Here is a sketch (drawn to scale for a lowmount drum) showing the fleet angles (2-1/2 deg in this case).

[Bush65]

Always amazes me the knowledge available on here.

John,

If I've got this right does that mean the default rope attachment point on my 8274 is at the wrong end of the drum?

The rope anchor on 8274's are on the wrong end. Warn lowmounts have the anchor on the correct side.

Of course, if the handing was correct for the 1st layer, it will be wrong for the 2nd and 4th layers. But it is more important to have the turns on the 1st layer nice and tight together (and that is what correct handing helps to achieve). Because the subsequent layers create considerable pressure on the 1st layer and we don't want the turns to spread apart. Each layer creates more pressure on those below.

The rule of thumb for determining the rope anchor point, is to use you right hand if the rope is right hand lay, and left hand if the rope is left hand lay.

Then align the index finger with the rope coming off the drum, wrapping your other fingers around the drum. The thumb is then on the side where the rope should be anchored.

[calle-fas]

Hi guys. Bumping an old thread here.

In order to move the centre of gravity further back, and gain better ground clearance I want to mount the forward winch in the passenger footwell of my 110 CSW just like the author. The main use for the winch is competition.

Having had a better look under the car today I figure it would be possible to route the winch rope over the transfer box (LT230) and then along the right hand of the chassis to the front. Fleet angle will be an issue, but if I put the winch as far back in the footwell as possible it would give me a little less than 1 m between the winch and the first fixed point.

Since it's a Td5 110 I won't have any real advantage of building it the Ibex way with a snatch block in the rear to route the rope forward due to the tank being in the rear. Instead I'll have a rear winch in the loadbed, and if I get into real trouble it will be possible to double the rope over the floor.

What do you guys think, is this doable or just plain stupid?

[bishbosh]

IIRC you need 5m (15 feet) between winch drum and fairlead to get an effective fleet angle so you will definately have a problem. However, if you can see the drum then you should be able to manage the bunching.

[calle-fas]

Thats hos I was thinking. The footwell gives room enough to sort out eventual bunching I hope.

Besides, how often do you really get correct fleet angle on a front mounted during competitions?

[Top90]

In order to move the centre of gravity further back, and gain better ground clearance I want to mount the forward winch in the passenger footwell of my 110 CSW just like the author. The main use for the winch is competition.

Out of interest, is there much ground clearance or weight to be saved?

While I don't know what winch you are using, most are about 30 to 35 kg (maybe) with plasma. Plus you'll need extra parts on the chassis to guide the rope and stop it drooping down and getting snagged somewhere when there is slack.

You could possibly improve both ground clearance and weight distibution by just moving the front axle forward an inch or two...

I like the idea of a 110CSW doing heavy duty competitions. Should surprise the 90s and special builds.

[calle-fas]

Well the comps I'm entering aren't that heavy. Yet. The challenge/trophy scene in Sweden is close to non-existing strangely enough. Very few ninetys or hybrids here.

I'll be using a low mount hydraulic winch. I was shocked when I weighed the car and found that with my electric winch and home made bumper the car had 40 kg overload on the front axle. That alone doesn't worry me though.

Moving the axle is a no go in this case since its my everyday driver.