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 Duncan52 05-25-2011 02:05 PM

Winch gear ratios

I'm trying to sort through the different older winches to find out which one is suitable, but am having very little luck discovering a site that lists these kinds of specs plus mounting base dimensions. Mostly interested in Barient and older Lewmar. Specifically 23, 26 and others. Many sellers list the overall mechanical advantage, but with no drum diameter of length or length of winch handle, it's hard to decipher. Anybody know either a site or the answers?

Duncan52

 JimsCAL 05-25-2011 07:51 PM

I have service pamplets with that information for the following Barient models: 27ST, 23ST, 21, 19, 18, and 10P. Let me know which ones might be of interest.

 obarut 05-26-2011 04:52 AM

I have a simple way to find out which winch is suitable.
Sail Force = v*v/80 kg where v is wind speed in knots. Normally for winch selection 50 knot wind speed is to be used. But you can use any speed you want.
If we assume it as 50 knots then Sail Force came out to be as 31kg.
Then calculate the sail area by taking into account for which sail the winch is to be used.
Sail Area x Sail Force will give you the Max Force which your winch needs to tackle.
Assuming by your arm you can only aplly 15 kg force and by dividing Max Force to 15 will give you approximate Power Ratio of the winch required.
Where
Power Ratio=(L/r)*GR
GR= Gear Raito of winch
L=Length of handle to be used
So if you can find Gear Ratio and radius of winch it is easy to decide.

 Duncan52 05-26-2011 08:33 AM

Winch gear ratios

Quote:
 Originally Posted by obarut (Post 734232) I have a simple way to find out which winch is suitable. Sail Force = v*v/80 kg where v is wind speed in knots. Normally for winch selection 50 knot wind speed is to be used. But you can use any speed you want. If we assume it as 50 knots then Sail Force came out to be as 31kg. Then calculate the sail area by taking into account for which sail the winch is to be used. Sail Area x Sail Force will give you the Max Force which your winch needs to tackle. Assuming by your arm you can only aplly 15 kg force and by dividing Max Force to 15 will give you approximate Power Ratio of the winch required. Where Power Ratio=(L/r)*GR GR= Gear Raito of winch L=Length of handle to be used r=Winch radius So if you can find Gear Ratio and radius of winch it is easy to decide.
I appreciate your formula, but the key is the gear ratio which I can't seem to find published. I'm specificcally looking for the ratios for a Barient 22. Do you know a source where this could be found?

 saillife 05-26-2011 09:17 AM

I might be misunderstanding your question so...... I was under the impression, with lewmars at least, that the number refered to the advantage using a 10" handle. i.e. a 20 would be 1 lb of force at the handle to 20 lbs on the line.

Try this site for specs on lewmars
Lewmar Winch Specs

 obarut 05-26-2011 10:22 AM

If you have the winch you can find gear ratio by turning it.
If you do not have the winch and are looking for the GR of Barient 22 it is again easy. Generally the numbers given in the specification of winches denominates its Power Ratio. If you know the PR you can find GR if you know the diameter of the winch. Generally winch specifications are given 10 inch handle. For your case:

GR=22/(10/r)

 Tweegs 05-26-2011 11:19 AM

Here's some good reference material for the Barlow and Barients winches:

Winch Service Manuals

Lots of other good stuff on the site also.

 roline 08-05-2011 08:40 PM

Barrient 22
ratio 1:1 5.4:1
12" 7.6 to 1, 40.8 to 1
10" 6.3 to 1 34 to1
8" 5.1 to 1 27.2 to 1

22ST is different

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