Outer Limits 4x4 Board

so if you put in a smaller diameter drum can you still fit a free spool or is there not enough room down the drum?

plenty of guys running narrowed drums with freespool. sheety and daves freespool works on a narrowed drum

mickyd555 wrote:so if you put in a smaller diameter drum can you still fit a free spool or is there not enough room down the drum?

have a look at wazza's on the flammin fabrications site, his drum and freespool is pretty impressive.

hammey wrote:

mickyd555 wrote:so if you put in a smaller diameter drum can you still fit a free spool or is there not enough room down the drum?

have a look at wazza's on the flammin fabrications site, his drum and freespool is pretty impressive.

I can 2nd this, I have one of Warrens freespools, very nice bit of equipment! Winch is off to the engineers tomorrow to have some more work done on the original housing.

Warrens freespool... http://www.flaminfabrications.com.au/De ... _FREESPOOL

I just tested my winch today after having the drum narrowed to 1.5 inches and lengthened 3 inches. I wanted to see if it would break the masterpull rope on a tight 1.5 inch wrap as some have been saying would happen. I left about 8 wraps on the drum, didnt use a snatch block, old 2.5 HP motor, 1 battery, 5600 pound truck stuck in clay with 36x13.5 TSL SS tires. I am happy with the results:

http://www.youtube.com/watch?v=kfvEV0V6kvI

Or high def:

http://www.japaneseswordcollector.com/v ... erline.wmv

mickyd555 wrote:so if you put in a smaller diameter drum can you still fit a free spool or is there not enough room down the drum?

The Wazza drum is 70mm dia. compared to the original Warn 89mm (3.5"). A 50mm drum is pretty tight but it could probably be done. I have contemplated welding a cut down front axle shaft to the drive pinion and connecting the drum to it at the outer end with a standard freewheel hub. Would probably work but I don't really trust the fwh to withstand shock loading having broken a few over the years. I wouldn't fancy the drum suddenly freewheeling when you are dangling off the rope on a steep hill.

lshobie wrote:I just tested my winch today after having the drum narrowed to 1.5 inches and lengthened 3 inches. I wanted to see if it would break the masterpull rope on a tight 1.5 inch wrap as some have been saying would happen. I left about 8 wraps on the drum, didnt use a snatch block, old 2.5 HP motor, 1 battery, 5600 pound truck stuck in clay with 36x13.5 TSL SS tires. I am happy with the results

1.5" is pretty small dia. The problem with rope, whether wire or synthetic, around small diameters is one of fatigue. i.e the life of your rope will be shortened, it won't break the first time but will break sooner than with a wider drum. Also you don't actually gain much as the amount of rope the first layer can hold is only some 4m.

Is the drum solid? High tensile? If you used mild steel the safety factor would be pretty low and probably inadequate for shock loading. Your test was just a steady pull but looked to be quite high loading.

As a matter of interest I entered your drum dimensions in a spreadsheet I wrote when working on my drum. Assuming 490Mpa ult stress steel (390MPa yield) 11 mm rope, and original 2.5HP motor. It gave the following results.

Max pull off 1st layer: 7,000kg
Max length of 11mm rope: 59m on 8 layers allowing 6mm below flange

Solid drum

Load factor (yield): Bending 5, Shear 4.6
Max deflection: 1.7mm

Tubular drum with 1/4" wall thickness

Load factor (yield): Bending 4, Shear 2.6
Max deflection: 2mm

For max shock loading such as can be experienced when winching up a steep bank I would like a LF of 5 or more.

Don't put too much store by the above figures as it is a while since I wrote the spreadsheet and may have omitted some of the entry data.

David

Thanks for the info, the wheeling we do around here is different than your comp stuff there, I rarely ever go down to the 2nd or 3rd layer on my winch, and holding a load on a shear cliff is something I dont really have to worry about. I'd be interested to know how one could come up with the figures to determine where the rope would fatigue (if possible) since every pull is different. I guess you would just be right in saying that it could fatigue earlier - but when is almost impossible to determine?

It is 1.5 inch solid stock, the guy who made it said it is hard stuff - don't know the particulars though.


I also always use a snatch block - not running against the clock here:)

Thanks!

Wouldnt one of the biggest concerns be the load on the rope at the fairlead on angled pulls - anything not straight??

lshobie wrote:I also always use a snatch block - not running against the clock here:)

Very wise. I always used a snatch block when I had a single 2.5HP motor. Halves load on winch, consequently motor turns faster so you don't actually lose much time, and you get more rope off the drum so the winch is "geared down" and pulls harder.

lshobie also wrote:Wouldnt one of the biggest concerns be the load on the rope at the fairlead on angled pulls - anything not straight??

Yes, anywhere the rope turns a sharp corner under load is not good for it and shortens its life. And if you have an angled pull the rope bunches up at the side of the drum. If you are trying to go forward but have an off-line anchor you can use a snatch block off another anchor point to align the pull better. I am continually surprised at how few people know how, or are too lazy, to use a snatch block. Of course if you are trying to pull the front of your truck sideways you have to have a side pull but watch out for bunching - or use a hand winch, or if you are really clever use multiple blocks but things start getting a bit complex then

David

If you go to the Dynamica website they have all the specs for the rope and this is a minimum radius to maintain strength. All the rope we use is made from Dyneema SK75, that is what is specified in the NZ rules (I did all the research for the rope specs) and while there are other ropes as strong they stretch too much to be safe.
Bending the rope arund too tight a radius will fatigue the rope and shorten the life. Your decision as to whether it will effect the usable life of the rope when on a really tight winch drum!

http://www.dsm.com/en_US/html/hpf/home_dyneema.htm

http://www.dynamica-ropes.dk/html/features.htm

The second link has a lot of very useful info and states bending radius should be 5 times the rope diameter. So for 10mm rope the drum should be 100mm! I don't know about anyone else but my drum is widened but is still standard size. if you have 8mm rope then 80mm is reconmended diameter.