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landonshaw · 22-02-2010, 05:48

I’m looking to make a Lazy Jake. My idea is to basically follow the attached drawing in dimensions.

A= 70%
B= 30%
C= 55%
D=80%
E=50%

http://www.angelfire.com/sd/douglas32/lazyhow.html

The line I will use will be 1/4 inch. Any spot that breaks off of the main line from the mast to point D on the boom will be woven into this line. I am thinking of leaving the Lazy Jake up permanently although I have seen where some are pulled to the mast while sailing. I have not read where there seems to be a chafing issue if left up.

I will have the lines relatively loose and the adjustment will be made at point B, C, & D to tighten or loosen.

Any thoughts on the chafing issue, design, or idea to leave up permanently? Also is it a good idea to leave the lines loose, and thoughts on how loose can it be?

sigmasailor · 22-02-2010, 06:59

I made something similar (it really is no rocket science) with the useful opted modification. I made mine so that I could pull everything forward to the mast (pulley attached to the spreader, line A on a simple cleat). This makes it a lot easier hoisting the sail and unclutters the lot when sailing and will avoid chafe. I always used the reefing hooks available to hook the lines and hide everything along mast and boom. I used this for 10 years and never had to replace anything. I made mine from 6 mm braided lines
I hate it (on charter boats) that the lazy jacks always manage to find a batten or two when hoisting the main.

landonshaw · 22-02-2010, 07:14

So you added a pulley and extended the main line, E to D, and pull everything to the mast. A halyard of sorts for the Lazy Jack. I assum you pull the lazy Jack to a point where the boom meets the mast. What do you do with the short lines attached at B & C. Do they hang down and get in the way or do you pull them up also?

sigmasailor · 22-02-2010, 07:23

I did not have C and I had a second pulley on B-D (a single line) attached to A-E (also one line); everything can always be tensioned; hence no flogging. I made it so the the second pulley stayed on the boom. I have no dimensions or percentages but used my imagination.
I used my reefing hook (yes where the boom attaches to the mast).

cal40john · 22-02-2010, 08:57

I was thinking about doing something similar, but using Amsteel Blue with eyesplices instead of blocks. The Amsteel is very slippery and supposedly easy to splice. Downside is it doesn't hold well on regular horn cleats.

John

barnakiel · 22-02-2010, 11:37

On my boat the layout is completely different!

The front leg runs from the mast (via blocks on the spreaders) to the 1st (front) boom point, then the 2nd line branches out from the 1st, and the 3rd from the 2nd. This helps avoiding the top batten getting caught on the lazy jacks.

b.

**Pblais** · 22-02-2010, 12:00

Quote:

I was thinking about doing something similar, but using Amsteel Blue with eyesplices instead of blocks. The Amsteel is very slippery and supposedly easy to splice. Downside is it doesn't hold well on regular horn cleats.

You can out think the problem. Line about 1 mm under a 1/4 inch is fine but don't get too thick. You don't need high strength because should the forces get too high it's better the line breaks. The small blocks are nice as you may want the tension of the whole set of jacks to be adjustable. Keeping the battens out of the jacks is some what a pain that you get better at doing with practice. You can also use a halyard on them and just take them in then redeploy them after hoisting the sails. Then you forget and now they are not up when you need them. I had that on the last boat and it worked but I got better at vrasing the sail and didn't need it any more.

I used slightly smaller line with small blocks and bitter ends whipped back to the line for an two inches. They adjust the tension under the end of the boom in the cockpit. This mimizes profiles and the strength of the whip will last longer than the line will. I would prefer the whips failed than generate forces beyond that. Ripping an eyestarp off the mast or boom is no easy fix. I blew a jack out in a gale once time. The rope broke and it was sort of a pain to replace all the lines but it didn't damage the boom or mast. It's all set so if I have to replace them I can rethread the old line and it can be done without climbing the mast. This isn't like making an anchor bridle. Under sail conditions it's doing nothing but waiting for me to drop the main.

One other tip. When making a sail cover don't cut the slots on the cover until after the the jacks are in place. It's impossible to measure them properly before adding the zippers. The bulk of the sail will mess you up every time.

barnakiel · 22-02-2010, 12:13

BTW, if there is no lazy-bag (stack-pack) attached at the bottom, it may make sense to substitute the lowest legs with nylon webbing - webbing better supports the sail and there will be less wear on the sail.

The alternatives are many - like the Dutchman system. I have not used it, but it looks very fine for some applications, doesn't it?

b.

sigmasailor · 22-02-2010, 12:26

That reminds of another advantage of 'my' system. No need to cut holes in the sail cover. Of course you do need to prepare it before dropping your main (one minute job). I fully agree with Paul also; don't make it too strong, better to break an easy to replace line than to rip screws or pop rivits out of your mast.

**s/v Beth** · 22-02-2010, 15:54

I'm making me one of these.

**Pblais** · 22-02-2010, 16:00

Quote:

I fully agree with Paul also; don't make it too strong, better to break an easy to replace line than to rip screws or pop rivits out of your mast.

Worse yet, in gale plus winds it might mess the sail up as well should it flog on the sail. Jacks are not meant to be structural, more like an idea of where the sail belongs on the way down.

cal40john · 22-02-2010, 21:44

I don't care about the strength of the Amsteel blue, I was going to use it because it will slide on itself without adding blocks to chafe the sail.

1/4" double braid is plenty strong to tear up your sail if something bad happens.

John

Abaco · 23-02-2010, 03:36

On my boat I mounted the pad eyes on the spreaders to open up the slot the head needs to go through. It makes it much easier to raise the main. I 2nd the option of being able to pull the lines to the mast. That way you don't have to cut up your sail cover.

sailstoo · 23-02-2010, 03:41

I installed Harken Lazy Jacks last year and am completely satisfied with the way they work, including chafe and stowage when not in use. I bought 'em brand new on eBay for about 1/3 of their list price. Here's the pdf on their design and installation, FYI.
http://www.harken.com/pdf/4060.pdf

NDH · 23-02-2010, 05:03

Quote:

Originally Posted by sailstoo

I installed Harken Lazy Jacks last year and am completely satisfied with the way they work, including chafe and stowage when not in use. I bought 'em brand new on eBay for about 1/3 of their list price. Here's the pdf on their design and installation, FYI.
http://www.harken.com/pdf/4060.pdf

Nice link. Made ours up about 3 yrs ago, spent a lot of time walking round marinas looking at lazyjack designs (bet the owners thought we were daft) Final design came out not dissilmar to the Harken PDF but I did use 25mm dia s/s rings instead of blocks and ran the lines (6mm) back down the mast for ease of adjusting. All worked a treat

I`ll also wager they were a good deal cheaper than the Harken ones