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Discussion Starter #1
I plan to build two PTO winchs, using worm gear reducers, front and rear, for my 416 DoKa.
I checked the old Werner manual, but i could not figure it out, what the Werner F64 winch's reducing ratio is.

I will appreciate your help.
 

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I think if you are custom building a winch for your Mog you are going about it from the wrong direction. I would say first you need to determine the following:
1) PTO output speed, 540 or 1000 nominal? What real RPM will you modulate the engine speed to?
2) Drum diameter?
3) Length of cable and number of layers that will take on the drum?
4) Pulling power required (at bare or full drum)?
5) Line speed when pulling?

Then you can calculate what the reduction (and power/torque requirements) of the worms should be.
 

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Discussion Starter #3
1- PTO speed: 540/1000 selectable. Engine RPM: It depends.
2- Drum length: Same length as Werner F64. Drum diameter: A little bit smaller than Werner F64.
3- Lenght of rope: 15-25 meter.
4- 8 ton at bare drum, 4 ton at last turn of the steel rope.
5- Pulling speed: It depends on situation.

I plan to build it approximate dimensions of Werner F64.
Yes, it should be calculated, but there is a physical working sample in front of us.

I just wanted to learn worm gear ratio of W F64 before buying a reducer.
 

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1- PTO speed: 540/1000 selectable. Engine RPM: It depends.
2- Drum length: Same length as Werner F64. Drum diameter: A little bit smaller than Werner F64.
3- Lenght of rope: 15-25 meter.
4- 8 ton at bare drum, 4 ton at last turn of the steel rope.
5- Pulling speed: It depends on situation.

I plan to build it approximate dimensions of Werner F64.
Yes, it should be calculated, but there is a physical working sample in front of us.

I just wanted to learn worm gear ratio of W F64 before buying a reducer.
I would judge that choprboy had a better overall grasp of the situation. As in all things Mog, the basic answer is It Depends. Werner configures the F64 all sorts of ways, depending on PTO speed, and line pull desired. One thing I would very much caution you on is the increased line pull on the first wrap, if you build a reduced diameter drum. A 25% reduction in drum diameter will result in a 33% increase in line pull, all other things being equal. Winch work is inherently potentially dangerous; don't add to the risks unawares.

My truck has an A50 hydraulic winch, 11000# first wrap, 9000# last wrap, using 200' of 1/2" steel cable, 4 wraps. My truck came to me without a cable (corrosion damage to the original), and I did a lot of research on winching and cables, before spending the extra $ on a 1/2"swaged cable, with a 34000# break. I now have 3x over winch pull, which is an industry standard for recovery work (NOT valid for hoisting). I might add that many amateur/ recreational winches do not meet this standard, and I would not either, if I used regular 1/2" wire (26000# break).

Your specs come out a bit unusual, based on my experience and research. 16000# is hefty, and a bit above the max configuration for an F64, using 540 rpm PTO, and 10m / min. In this configuration, they also spec 32 m x 14.3mm steel cable. At 9/16" equivalent std. steel wire, you will have 2x over working load. I don't find a last wrap line pull, but with such a short length (15-25m), I would expect it to be greater than 8000#. And, I do trust you are engineering for both torque and force on your winch? Further, I trust that you are incorporating an overload safety device? I strongly suspect that the PTO could easily generate sufficient torque to break a cable, before the engine stalled, so that safety requires operator anticipation (dump the PTO clutch in time).

Now, I am not clairvoyant, and don't just pull stuff out of my a**. The Werner info is to found on this link:


It is in German (try Google translate), and by no means complete, but it provides a good starting point. What I do not see is the (overall) reduction ratio. This material is not full-on engineering specs, and no drawings. The Werner F64 brochure does have the basic operating specs, if you scroll down. You will need to lay out your parameters exactly, and then back into the reduction ratio for whatever you build.

Since I was going there, I pulled out the three spec sheets, see attached:

2617199



2617201




Hope this helps.

Lee
 

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Lots of good info here but one main thing to consider is that what you are dreaming up has no reverse.

This is really important if you manage to pull hard enough to stall the system or you winch in and digest something or winch up against something you cannot back off, you are forced to cut the line which is under extreme tension and leads to scary outcomes. Been there, seen that.

You're plan is cool but I strongly suggest you get a winch with revers. Hydraulic winches are the bee knees.

Perhaps build your winch but power it with a reversible hydraulic motor. If you don't have hydraulics on your mog, there are plenty of hydraulic pumps out there that can be mounted to the PTO. Plumbing up a hydraulic system is pretty straight forwards. Not much research to do to learn enough to create a simple system.

Food for thought.
 

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If you put a hex on the other end of the worm gear shaft you could disengage the PTO if things needed to be backed off and wind it back out manually with a spanner perhaps? It wouldn't be quick but it would be a good addition to get you out of trouble if needed?
 

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That is a very good idea.

With a worm drive you at least know it will not snap back at you, or at least not very much.

I think that should be a design feature in TA10KU's winches, which I'm looking forwards to seeing be created.
 

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Spider gear mounted the winch from a US military truck on his Unimog. A little bit of digging can turn one up for a couple of hundred bucks. A winch is a substantial challenge to engineer from scratch.
 

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Spider gear mounted the winch from a US military truck on his Unimog. A little bit of digging can turn one up for a couple of hundred bucks. A winch is a substantial challenge to engineer from scratch.
I had been noodling on the engineering of an F64 winch, per the OP, and this is now the invitation to flail away on the subject. I re-read the previously posted spec sheets for the F64, and found there was more to work with than I originally thought. Mostly as a substantiation of the above, from Speedwoble, but also hopefully illuminating for the OP ( who seems not to want to calculate), here is how I see the numbers. For my convenience, I converted all into inches/ foot-lbs, etc.

Per Werner specs: drum diameter is 5.0" and rope is 0.56" diameter. To be especially nuanced/ persnickety, I used the diameter at the rope centerline of any given wrap to be the winding diameter. This assumes equal rope compression and tension below and above the centerline of the rope cross section.

radius to centerline of: first wrap 2.78", second wrap 3.34", third wrap 3.90"
circumference of: first wrap 17.47", second wrap 20.99", third wrap 24.50"
drum width is 318mm divided by rope diameter of 14.3 mm = 22 turns across the drum, per wrap

total rope wound on: first wrap 32 feet, first two wraps 70 feet, three wraps 115 feet (close to the stated 32m = 105', so far so good)

line pull 16000# first wrap x 3.90" divided by 2.78" = line pull on third wrap = 11,400#
11400 divided by 16000 = .712 from Werner 7000 daN x .712 = 4984 daN (again, close to published values)

Werner first wrap line speed, 540 rpm PTO is 10m / min = 394 inches/ minute
394 in/ min divided by 17.47 in/ rev of drum = 22 revolutions/ minute required
540 rev/ min divided by 22 rev/ min = 24 which is the necessary reduction ratio

torque on the drum or driven/ worm gear 16000# x (2.78" / 12 in/ foot) = 3706 foot-lbs

This is the point where anyone contemplating this build should step back and go "Whoa, Dude, that is a LOT of TORQUE". The forces on winch components are potentially HUGE. Reducing the drum diameter will reduce the torque load for a given line pull, but the big trade-off is that more wraps will be needed for a given rope length, and the diameter is increasing at a faster rate. This is results in a relatively greater loss of line pull from first to last on small(er) diameter drums. This is the bane of the small electrics, and a strong argument for the use of small diameter (for a given WLL) synthetic rope, as there is less diameter increase on the drum for a given length of rope (vs steel).

To continue, 3706 ft-lbs output divided by 24 (reduction ratio) = 155 ft-lbs torque supplied at input
Note: I have not factored for friction losses, theoretical is good enough for me, here.

I don't know the engine speed at which the rated 540 rpm output is obtained, someone can chime in.

Where we are coming to is some quick research at McMaster-Carr. The 24:1 listed worm reduction gearboxes are in the vicinity of 70 ft-lbs max, and cost circa $700. The only worm and worm gear pair shown at 24:1 reduction cost $96 and $156 respectively, but no telling if they can handle the loads and speeds. The 4 inch pitch diameter of the worm gear means a force of 22191 lbs on the tooth face, which will also be the force on the thrust bearing of the worm/ input shaft. Kind of substantial. I suspect lube is also important.

If one procures a ready made gearbox, it must attach to the winch frame sufficiently to resist that 3706 ft-lbs, or it under load it will simply wind itself around the winch frame until it rips the PTO drive shaft apart.

Checking with Fastenal's bolt engineering guidelines, I found an easy example that was relatively applicable. If the worm gear is bolted directly to the drum, and assuming a 3" diameter 4-bolt circle, there is 35625# shear load on the bolts. This would decapitate a single 1/2" GR 8 bolt, even if applied on the shank and not the threaded portion; the four 1/2" bolts per example would give about a 3X safety factor.

One can see why the electrics and the hydraulics use multi-stage planetary gears. They can be big, and speed decrease/ torque increase occurs at the very last, and acts directly on the drum, without a lot of other components to get loaded up. And, one can see why winches are expensive. For cost alone, Speedwoble has it pegged; look for used, and do minimal mods to fit.

EDIT: I have built a bunch of things in my life, and I can say with certainty, if someone is mass-producing an item, you cannot duplicate it as a one-off for even close to equal cost. Disregarding one's own time contribution is side-stepping the true cost issue. Not to say doing cool stuff can't have non-monetary rewards, but I prefer to not practice self-delusion.

Disclaimer: I am not an engineer, do not certify any of the forgoing, and publish strictly for the purpose of acquainting interested parties with the level of intensity this endeavor requires, for safety of all. And I definitely do not volunteer my carcass to stand by and observe the first home-brew winch created.

FWIW, I have attached my crib sheet:
2617893




Lee

Per an old ME I knew long ago: Figures don't lie, but liars can figure
 

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@photobldr - You say you are not an engineer, but you certainly think like one. Nice work on the calculations!

The general sentiment here is that a DIY winch will not be cheaper, better, or safer. That last point is extremely important. I'm not talking about “denting a fender - safety”; i mean serious “removal of body parts - safety”.

A good used winch can be found for far less than the raw materials of the DIY option. For example, i purchased a brand new, still in crate, Warn Sever Duty 18 for $1000. This is a 18k pound winch that is proven reliable and effective. It is what the military uses on humvees and LMTV’s. They retail for around $5k. It came with 100’ of 1/2 cable and the remote. Others can chime in on the great deals they got on their winches.

I totally support creativity and DIY projects. It is also important to go into such a project with as much information as possible. Not to mention, realistic expectations of the outcome. Only you can decide if the return on investment is justified.
 

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@photobldr, looks good but just to add more spice to the stew, the turns on the drum are more likely than not going to stack turn on turn but nest in each successive crotch which will lead to the rope crushing and/or submarining a turn or two as you just keep pulling. As pull force climbs rope construction and diameter must also to keep the winch from destroying the rope.

@TA1OKU, what by chance is your fairlead design? Fleet angle and distance between fairlead and drum also become failure points rapidly as pull force increases the lateral loading. Any thoughts on a capstan style?
 

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The general sentiment here is that a DIY winch will not be cheaper, better, or safer. That last point is extremely important. I'm not talking about “denting a fender - safety”; i mean serious “removal of body parts - safety”.........

I totally support creativity and DIY projects. It is also important to go into such a project with as much information as possible. Not to mention, realistic expectations of the outcome. Only you can decide if the return on investment is justified.
I am seriously grateful (I am not always serious, but when I am, I use the word serious (!)) for your response here. Now I know at least one person clearly got my point, which is to be very aware of the hazards and pitfalls.

When I looked at the OP's posts, I read into it a fairly casual approach to a project that really needs some intense analysis, just for safety alone. I could have simply stated my reservations, pretty much knowing what the calculations would look like. My real concern is that without supporting those reservations (think 3706 ft-lbs), it is too easy to dismiss my comments as just some old crank (which could be true, but not material to the present conversation) raining on the parade of an enthusiastic newcomer (definitely not the intent, even if it becomes a consequence). Hence the numbers. And a plea for anyone trying this to do their homework.

All of the previous posts have raised valid issues and concerns with the design of a winch. Another aspect of the controllability of a PTO winch is the dog clutch on the F64, so that bumping the PTO clutch lever won't suck the cable in inadvertently. On my RW1, the Werner roller fairlead has a strict warning against exceeding a 25 degree departure angle, to avoid excessive side loads. And the whole thing of synthetic rope gets messy, because of the flattening/ deformation of the rope: this affects winding, as well as sticking in the small gaps of roller fairleads. And don't neglect the overload protection, on most F64 models.

A brief bio: My dad was a very good science teacher, and being a small school, I had him for 7th, 11th and 12th grade (physics) science. He was highly analytical, and thoroughly embraced the scientific method; overall, extremely important training for me. Off to college, I flirted with mechanical engineering, but ultimately got a degree in architecture. Still did some ME courses, and took all the most technical stuff available in the architecture dept. For my post-graduate studies, I enrolled in the School of Hard Knocks. For some reason, I have yet to matriculate, despite decades of trying.

Lee
 

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"but ultimately got a degree in architecture. "

I knew it... I could tell by the handwriting and solution approach. Your handwriting also leads me to believe you went through school before the wide use of CAD in design studios.
 

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"but ultimately got a degree in architecture. "

I knew it... I could tell by the handwriting and solution approach. Your handwriting also leads me to believe you went through school before the wide use of CAD in design studios.
Well, it is worse than that. I started teaching myself drafting at age 10, and was allowed to take our high school drafting classes while in junior high (Dad had pull). Mid 60's, the industry standard was draft on paper, lay down the vellum, and ink a tracing with double nib pens. I doubt anyone under age 50 even knows what they are. Missteps were costly; worse than traditional typing with carbon copies, you just start over. I still have all my instruments, and still do most of my own projects by hand (but at least I am up to pencil on mylar). I have now progressed to using Adobe Illustrator, however.

And for the record, college graduation was 1976.

The computer maxim: GIGO ............ Garbage In, Gospel Out

Lee
 

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Your handwriting also leads me to believe you went through school before the wide use of CAD in design studios.
My first maxim of of drafting is if you can't do it by hand, put the mouse down.

Too many folks these days think because they can use sketchup, they are designers and draftsmen. Because they can load someone else's paths into a 3d printer, they are a "maker" (anyone else get the Dune heebeegeebees whenever someone says they are a maker?). But ask them to sketch up a solution, no matter how primitive to a problem and they go all cow eyed.

So on with the winch show! Any sketches of how it will attach?
 

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torque on the drum or driven/ worm gear 16000# x (2.78" / 12 in/ foot) = 3706 foot-lbs

The 4 inch pitch diameter of the worm gear means a force of 22191 lbs on the tooth face, which will also be the force on the thrust bearing of the worm/ input shaft. Kind of substantial. I suspect lube is also important.

If one procures a ready made gearbox, it must attach to the winch frame sufficiently to resist that 3706 ft-lbs, or it under load it will simply wind itself around the winch frame until it rips the PTO drive shaft apart.
Those little snippets there would be enough to make me leave a project like this well alone unless very experienced at fabrication and engineering. When that sort of force lets go it will make a mess of anything that stands in it's way!
 

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It's fun to see someone wanting to build a winch from scratch. A few decades ago that was a common way to have a little help to extract ourselves from places we should not have been. Our approach was somewhat less scientific than outlined so far. We would search junk yards for any kind of gear reduction. A ratio of about 30 to 1 is a good starting point. A 30 to one worm gear will usually hold it's load but any less ratio will tend to unwind on it's own, but that can have it's uses. More ratio gets slow, but still works.

We didn't care what speed the combination ended up, just that we could get forward motion! Our old trucks or Jeeps didn't have PTO's so we used some DC motor, like a starter, to power the contraption. Sure they blew up occasionally but we were smart enough to be standing back when the bad noises started. If the "grunt" gets too bad, or things don't move, add another sheave. Worked for us. Today's rule of thumb that a winch has to have "pull of 1.5 times the weight of the vehicle" (pick a number) is hogwash. With a little planning such as a few minutes with a shovel, move some rocks, an added sheave, etc, allows a small winch to do the job.

Using a PTO for power takes away a safety factor in this way: the PTO normally won't quit. Electric motors do, so a PTO winch has to have a weak point built in, a torque-limiting slip clutch (like agricultural implements use) or shear bolts. Look at how the old Deuce-and-a-halfs or 5 tons did it. A PTO winch sure will bind up, and if it does you can forget operating a dog clutch under a bind. If it is poor enough dog clutch to disengage under load it will pop out of gear under load. Have a way to insert a pry bar to back off that gear box manually.

One anti-bind compromise is to use a low enough gear ratio on a PTO winch that it will back off on it's own if the PTO is taken out of gear. That requires a really high torque (HP) gear box.

Please post what you come up with.

Bob
 

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I recall one of the Cincy folk making a joke about running the truck from the PTO via a bicycle. I feel like this situation could be similar, pedal power winch?

The X capacity dogma seems to come from Billavista over at pirate, his big book of winching seems to get flogged around a bit and his demonstrated worst case is GVW x 300% (3) and so everyone runs out and buys 16k badlands for their jeep and figures they bought the biggest winch that fits so of course it'll pull them out. Meanwhile in Technical Rescue, High and Low Angle Rope Operations Course, we were able to pull a whole fire truck across a parking lot using nothing but our bodies and what felt like 5 miles of rope. Using your sheaves and anchors the right way is key to making what you have work. I'd rather keep moving the anchor point(s) than risk killing the winch.
 

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.......come from Billavista over at pirate, his big book of winching seems to get flogged around a bit

......Using your sheaves and anchors the right way is key to making what you have work. I'd rather keep moving the anchor point(s) than risk killing the winch.
I swore I'd now stay off this thread, but just can't help myself. My physics teacher Dad (cited previously) would propose a bet with every new physics class, that he could move the entire class with ONLY 100' of rope and a large standing tree. And only a fool would take that bet. Answer below:

2618935


Tie the rope to the tree, have the entire class do a tug-of-war on the far end. Dad would station at the mid-point, leap up and land on the rope. They WOULD move; literally impossible not to. Bear in mind, the bet said nothing about how FAR he would move them. In fact, the laws of physics says that the rope itself CANNOT be perfectly straight; the two ends MUST be a tiny bit higher than the middle, just to realize the upwards force necessary to hold the center of the rope up (i.e. the rope has actually "moved" the class on it's own, assuming you started with the rope supported perfectly flat).

I have read, saved, and cited the "big book of winching". I have only about 0.80 X from my H50 Werner, but I carry a bunch of gear at all times, starting with a shovel, and progressing to 35000# WLL snatch block and shackles. It is really important to keep in mind how forces multiply, particularly as regards anchors and attachment point when using turning blocks. And important to know how multipliers can work for you.

Lee
 

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So just to get back on track here. @TA1OKU if you have a Werner laying about to prototype from, I'd recommend devising your "typical" gear ratio from the winch you have. Mark the input splines and make the drum; turn one and observe the other. To get real fancy you could get a tachometer tool and go that way if its already on a truck. The whole rest of this discussion is mostly us being a protective lot and not wanting to see you build your winch of winches only to fold a frame rail or catastrophically detach it.
 
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