OT: Mechanical question, rear axle as winch

Pay up your insurance!

Lee Schierer, McKean, PA

>While I can't comment on your rig other than please insure your insurance is paid up and you are fully covered. I can see several ways where someone could get hurt with this set up. Just don't ask me to be the guy in the cab of the truck running the gas pedal.

Lee

Re: OT: Mechanical question, rear axle as winch

Rob Stokes in North Vancouver

>Old ski hill rope tows used cut apart cars like this all the time, thought the spiders were usually welded and only one side was used.

I'd think your theory would work, but you need to be prepared to pull slack rope off either wheel. If the diff. in the car is or was a limited slip, allowing one wheel to do all the work will probably finish off the internal clutches - not that that's the end of the world as the diff. will continue to function as a normal open diff. after the clutches are gone.

Oh - and make sure - really sure that the car is anchored properly. You'd be wise to use your diff. housing as anchor points seeing as you're also using them as pulling points.

Rob

Re: OT: Mechanical question, rear axle as winch

Bob Fawcett

>Sounds good, but it won't work.

The diff will just let one side unwind. Running the drive in the car only makes the spiders turn faster.

I have a vague recollection from my yout'…

Rod Peterson -- Ormond Beach

>…of my dad and my uncle drilling a well behind my uncle's house using a similar sort of scheme.

Background: This would have been in the late '40s or at most, the very early '50s. Almost all cars/trucks (and all cars/trucks in our socio-economic circle) had standard transmissions, and most likely not limited slip differentials. I couldn't have been more than five or six, so my grasp of the mechanics and the engineering principles were rudimentary at best, and more likely, not at all. If there were safety aspects that were addressed, I was unaware of them or their need. Finally, my memory of this is dimmed by >50 years.

In fact, my understanding of the process really dates, not from the observation of the process at the time, but my later (much later) illumination as to what a differential is and how it works (as well as a capstan). So, with all those caveats in mind, they got the well drilled, and both lived into their '70s. Sadly, they're both gone and I can't quiz them on the project. I don't even know how they knew to do it unless it was a widely known process at the time (this was a fairly rural community—there are lots of workarounds done down on the farm that would never pass muster in a city—not to mention, who could afford to hire a well driller?).

I recall the one rim having two or three turns of rope around it functioning (I later learned) as a capstan. I don't know if they were alternately tightening and loosening the rope as it directly powered whatever mechanical contraption (which I can't recall) they were using—that is, a reciprocal motion, as in a hammer—or whether they used it as a capstan to control the operation of the other wheel which would have been attached in some manner to the aforementioned mechanical contraption—that is, a linear or continuous motion.

Frankly, as I type this out, there is far too much haze in my mind of some of the things that must have been done to make any sense out of. Now I feel like I just had to share the memory and legitimate at least the existence of the process. I make no warrants or recommendations based on this information.

Rod
Cursed with an early and continuing interest in mechanical things. Never met an object I didn't want to take apart to see how it worked.

Re: OT: Mechanical question, rear axle as winch

Bill Howatt

>I believe you have to weld the spiders to lock it up. A regular, non-slip, differential will always let the lightly loaded wheel spin as you found out by jacking only one wheel.

Bill

Re: Some additional thoughts

Luke Herzberg

>Looks like we've got opinions on both sides of the "works" or "won't work" fence, with most straddling as "might work, might kill ya!".

As far as only one wheel spinning, my theory is:

Winch wheel spins, capstan wheel does nothing. I don't believe this will happen because then the winch wheel would be doing all the work, tensioning the rope and trying to spin the capstan wheel in the process.

Capstan wheel spins, winch wheel does nothing. Possible, but only if the wraps on the capstan are loose enough to allow it. This is possible, but the winch wheel is always going to try to do SOME work, which would mean tightening the rope around the capstan or at least taking some slack out.

Both wheels do nothing. Possible. It's an old truck and could break at any time. ; )

Rear axle in question is not limited slip. I don't intend to make it undrivable in the future so welding spiders is out of the question. Total pull on rope is low, proably less than 600 lbs.

Tell ya what...I'm going to put the contraption together and I'll do a follow up post with a picture or two with the definitive answer.

Thanks,

Luke

Expanding on your single rim idea.....

Tim Greif - West of Chicago

>I believe you can make a single rim winch work pretty well. With a standard differential (non limited slip), you do indeed transfer power to the most lightly loaded wheel. An old trick we used years ago in my off-road jeep days was to install two parking brake levers, one for each rear wheel. If one drive wheel started spinning, just apply partial brake to that wheel only and it would transfer power to the opposite wheel. On your setup, modify the brake cable to the emergency brake (or parking brake as it's called today) to only apply to one wheel, the non-winch wheel. This should keep the power on the winch wheel. Don't use the second rim, just return the rope and tie off on the axle housing. Speed will be slower but control is better. Releasing the emergency brake should give you a safety too. Let us know what works.

Or maybe I'm full of it, which wouldn't be the first time

Re: Expanding on your single rim idea.....

Gene Gauss

>I did just what you are trying to do to bail a well about 30 years ago, but I used only one wheel of a farm tractor as a capstan. It worked because farm tractors have individual rear wheel brakes (for traction control and tight turning). I locked the brake on the left wheel, jacked and removed the tire from the right wheel, and used a single loop of 1/2" polypropelene rope around the wheel and through a pulley on a 15' high tripod (made of sturdy saplings) over the well. I dropped and pulled the the bailer, by loosening and tightening the loop by pulling on the rope by hand as I needed. It still needed a fair amount of pull to get enough friction to pull the full bailer. That's what almost got me into trouble. I tried to use two loops around the wheel to reduce the effort on my part, and one loop got caught under the other and started to wind the rope onto the wheel. Once the bailer got to the pulley, that tractor, which weighed almost two tons, just lifted up on that side until the rope slipped off the wheel, and dropped the tractor back down onto the blocks supporting the axle. (Experience is what comes from screwing up.) I understand that you can drill a well by this technique, alternately lifting and dropping a well drilling bit to pound down through the dirt and into bedrock until you hit water. Gene Gauss

Re: Expanding on your single rim idea.....

Rod Peterson -- Ormond Beach

>> I understand that you can drill a well by this technique, alternately lifting and dropping a well drilling bit to pound down through the dirt and into bedrock until you hit water.

The very process I witnessed lo these many years ago as described below.

Rod

Re: OT: Mechanical question, rear axle as winch

Bill White

>Having grown up with my Dad in the oil business I saw many a "rig-builder" drive to the locations, take the rear wheels off the old sedan, bolt on a "cat head" (capstain), throw a set of pulleys on the derrick, and then hoist rig parts into place. Always scared the h#*% outa me, and Dad said "stay away from those rig builders. They're crazy". He was right.

Bill