On Jul 22, 11:16*pm, Frank Whiteley wrote:
On Jul 22, 6:38*pm, sisu1a wrote:



On Jul 22, 4:50*pm, Chris Nicholas wrote:

Has anybody in the good old US of A developed a printed, available,
specification for the pay-on gear for Dyneema etc. rope – like low
weight (aluminum? - note USA spelling!) rollers, low friction and low
inertia bearings, anything special needed for the drum , etc.?

I suspect that there is scope for saving inventing too many wheels
twice over.

(And for the avoidance of doubt, I am NOT going to get into the Bildan/
DC/DJ etc. spats – you are all welcome to keep those among
yourselves.)

Chris N.

While I'm sure there *are such documents handy, if your goal is
'saving wheels' one can (and is better off...) doing away with the
level wind mechanism altogether, which is itself a source of
additional hassle in most operations. The trick is to use a high
enough aspect drum and have a long enough run between the fairlead
assy and the drum, somewhere around 1:18 I believe, comparing drum
width to run length between the two mechanisms according to German
DAeC.

Assuming a bigblock/TH400/truck rearend setup is what you're leaning
towards, final drive gearing needs to be selected based on drum
diameter, since larger diameter drums call for higher gear ratios in
the rearends... a small price to pay considering. There are
spreadsheets and other files covering all this on winchdesign BTW

-Paul

PS. join the winchdesign group and comb the postings and files there
as well as keeping up on new ones...http://groups.yahoo.com/group/winchdesign/*-that is if you can
handle more episodes of the Derek/Bill show *

The ratio of drum width to feed is 10:1 for unassisted level winding.
So an 8-inch wide drum needs 80 inches. *The Gehrlein Model 62
distance is about 88 inches from axle to rollers. *The drum I had
built is 8.5 inches wide. *A high ratio can only make it more
effective.

That said, the winch at Littlefield, TX, uses a simple level wind that
is easy to maintain and works very well on their wide drum. *The wide
drum advantage is the there is a small shift in the torque arm as the
drum loads.

Frank Whiteley

The German DAeC winch recommendation calls for an 18:1 ratio between
fairlead pulleys and the drum width. However, that's for steel
cable. "Plastic Rope" seems to spread out nicely so even 8:1 seems to
work.