Photos needed. Shed full of S**t Auction

[Tony Wheeler]

Originally Posted by Richard Farrant

Tony and Ian,
Another reason for not having many layers of rope on the drum is due to "effort required". Maybe experience told them of the usual length of pull required, the more unused rope on the drum, the more effort required to wind the handle.
Each layer will increase the load on the operator, the only other option is to use some thing like a Trewhella rope grab, to clamp on the rope down its length in order to start on bottom layer.

Of course if shortage of steel wire rope then it could be the real reason.

I spent a good deal of time repair and testing all kinds of winches for the army from hand operated winches, recovery vehicles through to 30 ton winches on Caterpillars. Each layer on the drum on a vehicle winch, reduces its pulling power before the cut out trips in.

regards, Richard

Sound logic Richard but when you do the math you find this winch is geared ridiculously low for recovery work. It's permanently in low ratio, which is designed for lifting 2 tons vertically over a few feet, not pulling a one ton vehicle horizontally over 120 feet! It can be calculated that would require 1400 turns of the handle, advancing the jeep only 1" per turn. The only way this winch would be remotely practical is with the handle set at minimal length, eg. 6" or less, and wound rapidly with one hand, in the manner of cranking a motor. That's no problem as the force required is less than 20lbs, so you could keep up a steady rate of 100 rpm or more, which would get the job done in a few minutes. However I believe it would be much better with a higher ratio and the handle set longer, so you could shorten it over the easy stretches and go much faster. That said though it's a helluva lot better than no winch at all!

[Richard Farrant]

Originally Posted by Tony Wheeler

Sound logic Richard but when you do the math you find this winch is geared ridiculously low for recovery work. It's permanently in low ratio, which is designed for lifting 2 tons vertically over a few feet, not pulling a one ton vehicle horizontally over 120 feet! It can be calculated that would require 1400 turns of the handle, advancing the jeep only 1" per turn. The only way this winch would be remotely practical is with the handle set at minimal length, eg. 6" or less, and wound rapidly with one hand, in the manner of cranking a motor. That's no problem as the force required is less than 20lbs, so you could keep up a steady rate of 100 rpm or more, which would get the job done in a few minutes. However I believe it would be much better with a higher ratio and the handle set longer, so you could shorten it over the easy stretches and go much faster. That said though it's a helluva lot better than no winch at all!

Hi Tony,
If it were a longer rope on there, and thus more layers, as each layer built up it would require less turns on the handle as effective drum diameter is increasing. It gave you the incentive not to get in a situation to use the winch!

cheers Richard

[Tony Smith]

Originally Posted by Tony Wheeler

........ because the winch is fixed permanently in low ratio, so you'd need to shorten the handle to wind it rapidly, particularly when reeling in loose cable after winching.

Attachment 62966

I'd like to see a better pic of the mounting of the vertical post that supports the crank handle/shaft. Is it fixed in a vertical position? If it pivots about the chassis rail, then the drive gear could be withdrawn from the Low Ratio position and re-inserted in the High ratio position. The attachment of the cranking shaft to the drive gear seems too over-complex for a fixed alignment.

[Brett Nicholls]

You read my mind Mr Smith

Regards,
Brett.

[Tony Wheeler]

Originally Posted by Tony Smith

If it pivots about the chassis rail, then the drive gear could be withdrawn from the Low Ratio position and re-inserted in the High ratio position.

That would be one solution Tony, another one would be to make the post itself removable, and have two separate locating positions on the chassis rail, eg. short piece of box section for it to slide into, with a simple locking pin.

Either way though it would explain the redesign from the early version where the post appears to be fixed vertically on the bumper bar, or at best, hinged at the base with a locking pin hole in the brace plate for high ratio position. Perhaps they found this arrangement was not robust enough in high ratio, which being only 4:1 would require considerable force on the crank handle. And of course if it was indeed fixed vertically, then they would quickly discover in trials that 16:1 was impractical in most situations, and certainly impractical for winding in loose cable.



Either way I think you're onto something Tony because if you look at the 9th Div jeep winch you'll notice the drive gear is at least half way out, which indicates they haven't pushed it back in far enough for the Dawn locking pin to engage:



This is something I do myself routinely on my Dawn No. 5 winch, purely through laziness when changing ratios. It's not necessary to engage the locking pin, but of course when I go for a spin around the backyard the handle sometimes falls out, and next time I need to use the winch I have to search for it in the long grass! In the case of the jeep that can't happen, and since you'd be changing ratios repeatedly you wouldn't bother with the Dawn locking pin each time, it would just be an unnecessary nuisance.

Whatever the case in practice though, the fact that the drive gear is so far out in this photo tells us the entire shaft is removable, which can only be for the purpose of changing ratios. That would make this winch infinitely more practical.

I suspect the shaft attachment only looks complex because they've retained the Dawn handle mounting parts, it's possibly just a piece of box section or channel enclosing them and welded to the long shaft. However I'm not sure why they'd retain those parts, rather than simply join the two shafts with a welded sleeve. Perhaps they wanted to maintain the integrity of the Dawn handle mount for interchangeability purposes, esp. for the first batch which must be considered a trial mod only. Given that these winches were used elsewhere in standard form it would make sense not to ruin them for those applications, at least not until the jeep mod was fully proven in the field. Even then it would still make sense not to ruin them if possible.

[Tony Wheeler]

Just to clarify, these are the Dawn locking pins I'm on about. You can see the drive gear is fully home when the locking pin is engaged, as opposed the 9th Div jeep where it is partially out:







These pins are spring loaded and will engage automatically when you push the drive gear in, but only if they're well lubricated. If they're dry of lubricant like my high ratio locking pin they will jam and hold the drive gear partially out, just like a sticky door lock plunger jams on the striker plate. However it's actually much better that way because you don't have to disengage them when changing ratios, which would be even more of a nuisance on the jeep because you'd have to reach over to do it. The only reason I lubricated my low ratio locking pin is because the handle kept falling out when I did laps around the back yard. That can't happen on the jeep, so once the locking pins got a bit sticky through mud and dirt and water etc. you'd leave them that way deliberately.

Thinking further on the shaft attachment I don't believe you could weld it solid with such a long shaft, you'd need some movement in the joint to allow for the inevitable misalignment due to the moveable post, and also as the chassis flexes. That being the case they've probably gone about it in the simplest way possible, using the existing Dawn parts rather than designing and fabricating new parts.

Anyway nice work Tony, you've convinced me it was designed for high and low ratio use. As such I'm even more impressed with this jeep mod, maybe I'll stick the Dawn No.5 on the front of my F15A!

[Tony Wheeler]

Originally Posted by Tony Smith

The attachment of the cranking shaft to the drive gear seems too over-complex for a fixed alignment.

What about a piece of box section or channel, which fits over Dawn part A, or similar but thicker fabricated part A, and slotted for upward removal of the post and shaft assembly, which can be repositioned further back on the chassis, after moving the drive gear to the high ratio position. In other words a two-piece assembly, with the shaft detachable from the drive gear. Why else would you have a pin and slot arrangement, which is clearly the case here?





On this jeep version they've clearly dispensed with Dawn part B so it's likely they dispensed with part Dawn part A too, and used a much thicker square block, say 1" thick, drilled for the shaft and held in place by the Dawn nut, and pinned on the sides for the slotted box section piece.

That would work nicely I reckon, although it does involve two separate operations to change ratios. On the other hand it may be a lot easier than with a floppy joint. Either way you have to handle the gear end to poke the shaft in the hole so there's probably not much difference.

Of course the ideal set up would be a uni-joint of some kind, with a post that swings back on a pivot so you don't have to remove it to change ratios. However I don't believe that's what were seeing in these jeep photos.