Outer Limits 4x4 Board

If you are bored

http://neuralfibre.com/paul/4wd/4wd-win ... the-weight

Paul

me3@neuralfibre.com wrote:If you are bored

http://neuralfibre.com/paul/4wd/4wd-win ... the-weight

Paul

Are they pop rivets holding your fairlead on?

Will be interesting to see how the alloy holds out.

sierrajim wrote:

me3@neuralfibre.com wrote:If you are bored

http://neuralfibre.com/paul/4wd/4wd-win ... the-weight

Paul

Are they pop rivets holding your fairlead on?

Will be interesting to see how the alloy holds out.

I'd be suprised if it DIDNT fail, It might take quite some time depending on use, but they will fail! Ally rivets tend to hate vibrations in a big way, they also hate expansion and contraction to do with heat.

In my very limited experience aluminium fail's catostrophically with minimal warning compared to steel as well, so I'd be even more cautious than normal when winching, especially when larger angle's or heavier loads are concerned. Maybe I just over engineer thing's but I'd almost say that your chassis mounts will fail as well, it doesnt look like it's gussetted to prevent it from twisting under load, so a forward pull with an upwards twist = torn mount where the gusset's in the channel finish beside the chassis. It might be worth to at least tack or in your case rivet another length of chanel to the bottom of the mount to help prevent this twisting.

At least your running synthetic rope Paul, it's not the weight factor that sells me on it, but the fact it hold minimum energy when it break's compared to steel cable

I am far from an engineer so I'm just taking badly un-educated guess's at what my un-trained eye's see. I really hope for your safety I'm wrong

me3@neuralfibre.com wrote:If you are bored

http://neuralfibre.com/paul/4wd/4wd-win ... the-weight

Paul

You flame and complain about a lot of things and products and workmanship then go and do that?

AWESOME!

Funny the rivets don't worry me as much as the alloy mount itself. I don't feel that 8mm ally is strong enough for this job.

The concern is that by definition, failure will occur with a lot of rope tension. So say the fairlead fails, you are going to have the rope sitting on the cutout in the bullbar, under load, and have to work out how to get rid of the tension in the rope when you don't have a fairlead any more.

I do like the idea of approaching this job with a "keep the weight down" strategy though. But I think it's back to the drawing board... maybe the same deal with thicker ally and high tensile bolts instead of rivets? And mount the fairlead to the same mount as the winch as well I think. You can't trust the bullbar for this..

person behind you on the freeway is gonna be gettin a free winch one day. and is it just me or does it look like the cradle has a bow in one of the pics?

You need the thicker rope size if you are going to use a winch block, as it will double the pulling force - 9500×2 = 19,000lb.

on this topic... i always thought the blocks worked because the rope "sees" 9500lb tension along its entire length, so doubling it back via the block means that it applies double force (9500lb on the winch mount, 9500lb on the recovery point on the truck that the leading end is on).

so i thought the only part of the recovery gear that would see 19,000lb would be the block itself and what the block is anchored to.

bad_religion_au wrote:

You need the thicker rope size if you are going to use a winch block, as it will double the pulling force - 9500×2 = 19,000lb.

on this topic... i always thought the blocks worked because the rope "sees" 9500lb tension along its entire length, so doubling it back via the block means that it applies double force (9500lb on the winch mount, 9500lb on the recovery point on the truck that the leading end is on).

so i thought the only part of the recovery gear that would see 19,000lb would be the block itself and what the block is anchored to.

I agree with this; that's exactly the point of the whole winch block approach.

chimpboy wrote:

bad_religion_au wrote:

You need the thicker rope size if you are going to use a winch block, as it will double the pulling force - 9500×2 = 19,000lb.

on this topic... i always thought the blocks worked because the rope "sees" 9500lb tension along its entire length, so doubling it back via the block means that it applies double force (9500lb on the winch mount, 9500lb on the recovery point on the truck that the leading end is on).

so i thought the only part of the recovery gear that would see 19,000lb would be the block itself and what the block is anchored to.

I agree with this; that's exactly the point of the whole winch block approach.

So if I used enough snatch blocks .. I could use a shoelace ..

There MUST be 19,000lb of force back against the object you are pulling .. action\rection etc .. the snacth block only effectively halves the winches gearing .. from say 200:1 to 400:1 .. less speed more torque.

love_mud wrote:

chimpboy wrote:

bad_religion_au wrote:

You need the thicker rope size if you are going to use a winch block, as it will double the pulling force - 9500×2 = 19,000lb.

on this topic... i always thought the blocks worked because the rope "sees" 9500lb tension along its entire length, so doubling it back via the block means that it applies double force (9500lb on the winch mount, 9500lb on the recovery point on the truck that the leading end is on).

so i thought the only part of the recovery gear that would see 19,000lb would be the block itself and what the block is anchored to.

I agree with this; that's exactly the point of the whole winch block approach.

So if I used enough snatch blocks .. I could use a shoelace ..

There MUST be 19,000lb of force back against the object you are pulling .. action\rection etc .. the snacth block only effectively halves the winches gearing .. from say 200:1 to 400:1 .. less speed more torque.

No, if you used enough snatch blocks then in theory yes, you could use very light rope. The point is that the rope is being pulled twice as fast as the vehicle is, so yes the speed is halved but so is the load on the rope.

I could be wrong but that's how I understand it. You are effectively using two pieces of rope, each of which sees half the load.

Here is someone else's diagram:



That is how I've always understood it to work. The equal/opposite reaction concern you had is covered there as you can see.

As above thats exactly how it works, reduces winch load, rope load, but WILL NOT reduce the load on the bullbar. The full load will also still exist on the chain/winch stap attached to what ever your winching from eg a tree, which is the short length in the drawing

hulsty wrote:As above thats exactly how it works, reduces winch load, rope load, but WILL NOT reduce the load on the bullbar. The full load will also still exist on the chain/winch stap attached to what ever your winching from eg a tree, which is the short length in the drawing

it will reduce load on the bullbar IF the rope is attached to a recovery point on the chassis, not the bullbar.

and in most practical cases, it will double the load on the short length, BUT as these extentions are usually similarly rated to the cable, AND they are doubled over usually (you put the block in both ends of the strap) the load is half of what the snatch block sees. of course if you use a single run of rope/chain to the anchor then it'll see the same load as the block.

chimpboy wrote:Here is someone else's diagram:



That is how I've always understood it to work. The equal/opposite reaction concern you had is covered there as you can see.

Now imagine using the 100ft winch extension instead of the short one. That's where the 19,000 comes from.

Means you have a LOT of flexability vs putting 150ft on the winch.

Paul

Shouldn't you work out the weight saving using the difference in weight between the steel and alloy bar, not the total weight of the steel bar?

I have read some of your other "Meanderings" as you put it i have have generally thought you have done your homework and calculations on your projects, but on this one you have proved me wrong.

The channel you bought is called a PFC (Parrallel flanged channel) it should of atleast been T5 or higher, the setup you have opens the pandores box of shit to go wrong.

(1) If someone gets injured/killed while you are winching and the shit fails your insurance won't cover anything, as well as you could be liable for charges such as negligence by poor design, manslaughter etc

(2) The bar fails and you lose the car over the edge of a cliff, insurance won't cover due to defective/poor engineering

(3) If you where so worried about weight over the front axle why not install a haymen reece receiver hitch in the front and get a cradle arrangement and anderson plugs, then you can use the winch front or rear, and store it in the luggage area of your vehicle when not in use, as i read that you plan on not using it that much anyway.

(4) You could actually make the mount out of alloy but you would first have to understand the principles of the way the material is going to react once load is exertated on it.

If you would like assistance on metals and the like speak to Gwagonsteve off this forum he is very knowledgable in this area, i'm suprised he hasn't piped up yet.

You also have the advantage of driving a vehicle that lends it self to having heavy springs changed in and out with relative ease, the weight issue on the front of a 100 series in my honest opinion is a dead argument.

As for the pop rivets all i say is "SHRAPNEL........INCOMING"

I tried to make it fail.

Ran out rope to last run on the drum.
Connected to tree uphill
Locked up Landcruiser with brakes and lockers and park
Attached Disco to landcruiser
Locked up Disco

Winched in
Mount twisted a little (I was watching it very closely)
Winch slowed
Cruiser Dragged
Strap between card came up tight
Winch slowed more
Technora (high temp) rope snapped where it was bent sharply over fairlead.
Mount showed no permanent deformation

It if breaks, it breaks :)

Assuming your winch is NOT mounted directly to your bar - anyone seen a strength or engineering analysis done on a metal plate mount?
Care to guess at the strength of the feet on the winch (they are alloy)
If the winch is sitting 250mm higher than the chassis rails, vs between them like this, that's a lot of twisting too. I frequently see bullbars movig up and down whilst winching, to spring back when done.

But yes, it's an experiment.

Paul

Evil 73 wrote:I have read some of your other "Meanderings" as you put it i have have generally thought you have done your homework and calculations on your projects, but on this one you have proved me wrong.

The channel you bought is called a PFC (Parrallel flanged channel) it should of atleast been T5 or higher, the setup you have opens the pandores box of shit to go wrong.

(1) If someone gets injured/killed while you are winching and the shit fails your insurance won't cover anything, as well as you could be liable for charges such as negligence by poor design, manslaughter etc

(2) The bar fails and you lose the car over the edge of a cliff, insurance won't cover due to defective/poor engineering

(3) If you where so worried about weight over the front axle why not install a haymen reece receiver hitch in the front and get a cradle arrangement and anderson plugs, then you can use the winch front or rear, and store it in the luggage area of your vehicle when not in use, as i read that you plan on not using it that much anyway.

(4) You could actually make the mount out of alloy but you would first have to understand the principles of the way the material is going to react once load is exertated on it.

If you would like assistance on metals and the like speak to Gwagonsteve off this forum he is very knowledgable in this area, i'm suprised he hasn't piped up yet.

You also have the advantage of driving a vehicle that lends it self to having heavy springs changed in and out with relative ease, the weight issue on the front of a 100 series in my honest opinion is a dead argument.

As for the pop rivets all i say is "SHRAPNEL........INCOMING"

The issue was mostly cost actually. Too cheap to buy a real bar. Alloy is more fun than steel.
The weight issue was a bonus.

Paul

me3@neuralfibre.com wrote:I tried to make it fail.

Ran out rope to last run on the drum.
Connected to tree uphill
Locked up Landcruiser with brakes and lockers and park
Attached Disco to landcruiser
Locked up Disco

Winched in
Mount twisted a little (I was watching it very closely)
Winch slowed
Cruiser Dragged
Strap between card came up tight
Winch slowed more
Technora (high temp) rope snapped where it was bent sharply over fairlead.
Mount showed no permanent deformation

It if breaks, it breaks

Assuming your winch is NOT mounted directly to your bar - anyone seen a strength or engineering analysis done on a metal plate mount?
Care to guess at the strength of the feet on the winch (they are alloy)
If the winch is sitting 250mm higher than the chassis rails, vs between them like this, that's a lot of twisting too. I frequently see bullbars movig up and down whilst winching, to spring back when done.

But yes, it's an experiment.

Paul

Theses are generally in compression, they are not being pulled against in pretty much all the mounting ive seen over the years, they would defianteley snap if pulled in the other direction. As far as i see it have a look at the way the manufactures ARB,TJM etc mount the winches to the bars they are all in compression which then only leaves the bar itself to fail. (NOT THE POP RIVET) LOL

Ben

Poor people cant afford cheap things.

me3,

You seem to collect a lot of other peoples thoughts on projects/write ups. Do you have the weight of the steel TJM/ECB winch cradles that sit behind their alloy bull bars?

You've mentioned that the alloy twisted, if it keeps doing this do you think it might fatigue then fail?

The big problem with winch failure it that it can be life threatening. either the car slides out of control or the cable snaps and hits someone. Your fairlead mounting with rivets is dangerous.

Evil 73 wrote:If you would like assistance on metals and the like speak to Gwagonsteve off this forum he is very knowledgable in this area, i'm suprised he hasn't piped up yet.

He hasn't woken up yet... fainted when he saw the pop rivets

chimpboy wrote:

Evil 73 wrote:If you would like assistance on metals and the like speak to Gwagonsteve off this forum he is very knowledgable in this area, i'm suprised he hasn't piped up yet.

He hasn't woken up yet... fainted when he saw the pop rivets

or smacked in the head with a flying fairlead... or shot in the arse by some rivets popping.

love how the hawse is bolted on but the mount is pot riveted.

nicbeer wrote:love how the hawse is bolted on but the mount is pot riveted.

saves weight.

nicbeer wrote:love how the hawse is bolted on but the mount is pot riveted.

No they are only bolt heads to save on weight the thread has been cut off as its too heavy, and he used some pva glue (due to its lightness) to hold the alloy hawse to the chequerplate whcih does kinda resemble the inside of an old bake bean can. (empty of course, due to weight)

GOD STRUTH!!!

bru21 wrote:GOD STRUTH!!!

bad_religion_au wrote:

hulsty wrote:As above thats exactly how it works, reduces winch load, rope load, but WILL NOT reduce the load on the bullbar. The full load will also still exist on the chain/winch stap attached to what ever your winching from eg a tree, which is the short length in the drawing

it will reduce load on the bullbar IF the rope is attached to a recovery point on the chassis, not the bullbar.

and in most practical cases, it will double the load on the short length, BUT as these extentions are usually similarly rated to the cable, AND they are doubled over usually (you put the block in both ends of the strap) the load is half of what the snatch block sees. of course if you use a single run of rope/chain to the anchor then it'll see the same load as the block.

Thats right, but I can just see the next write up, " how to pop rivet a light alloy recovery hook to your bullbar" ahahha this is madness and using such light PFC alumnium too.

You should really crunch the numbers on all this mate and check the material grade etc its relatively straight forward to do for something that simple looking.

now that the template is made, a steel one should happen quickly