Junk rig for Joe 17 trailer sailer

  • 15 Mar 2017 13:50
    Reply # 4668303 on 4556642
    Anonymous member (Administrator)

    Jami

    First of all, I count the panels and battens from top. The highest sheeted batten is batten no. 2 in my sails (don’t count the yard as a batten), which takes the highest load. The battens below and above, batten 3 and batten 1 also take some load. On my last rig, for Ingeborg, I made both batten 1 and 2 stronger than the others. It sounds odd that batten no. 1 sees any load, but on the fanned tops of my sails, it appears to see some compression.

    As for how to tie on the sheetlets, there are no rules carved in stone here. Still, I recommend that you tie it in a way which keeps the batten end from protruding aft of the leech, this to avoid snagging the sheetlets.

    Arne


  • 15 Mar 2017 13:39
    Reply # 4668262 on 4556642

    PJR has webbing loops sewn to the sail, passing either side of the end of the batten and then sewn together. This effectively transfers the sideways loading from the sheet onto the batten, but in the long term, I've had problems with chafe.

    There can be an eyelet in the sail, just below the batten, but the batten must be strongly fastened to the sail and there should be some chafe protection on the edge of the sail.

    I've come to prefer this method: The batten is bolted through an eyelet in the sail, so that sideways loading is catered for and the end of the batten remains exactly flush with the leech. There is a plug in the end of the tubular batten; in the end of this plug there is a hole which is given a "trumpet" mouth with a rounding off cutter. There is then a hole drilled at an angle of 45 degrees upwards from inside this aperture and through the wall of the batten tube. I can then pass the end of the sheet span up through this hole and tie a stopper knot. As the sail swings from side to side, the sheet span can lay against the rounded off surface rather than a sharp corner. Even so, I use Dyneema sheet spans for longevity, as it is the most chafe resistant material for lines. For this size of boat, 3 or 4mm will be enough.

  • 15 Mar 2017 13:15
    Reply # 4668238 on 4556642
    This might sound stupid, but I have no access to PJR and haven't seen a discussion about this before:


    Are the sheetlets to be fastened to the battens or to loops sewn on the sail itself?

  • 15 Mar 2017 13:03
    Reply # 4668222 on 4556642

    Ok, that means battens 3&4 in Arne's Johanna-type sail.

  • 15 Mar 2017 10:02
    Reply # 4668036 on 4667942
    Jami Jokinen wrote:

    Thanks, Arne.

    Hmm... I would have an extra 3m of the lighter batten tube (25mm), if I made three battens from 35mm instead of the yard and batten three. The one to go with would be batten two, or would it?

    (this is all doable, because my sail is still on the way)

    The top two sheeted battens are the ones which are most heavily loaded.
  • 15 Mar 2017 10:00
    Reply # 4668035 on 4667928
    Jami Jokinen wrote:
    David Tyler wrote:

    ...the use of a span, attached to the 1/3 and 2/3 of length points, reduces the demands on the tube.

    Sorry David, but I'm not familiar with the terminology here. Could you be more specific for a dummy, please?


    A line is tied to the (3m) yard at the 1m and 2m points, a little bit slack so that it forms a triangle. In the middle of this line you tie a loop and attach the halyard block to it. You can see a span like this on the peak halyard of a gaff mainsail, to spread the load and reduce the demands on the spar.
  • 15 Mar 2017 08:57
    Reply # 4667942 on 4556642

    Thanks, Arne.

    Hmm... I would have an extra 3m of the lighter batten tube (25mm), if I made three battens from 35mm instead of the yard and batten three. The one to go with would be batten two, or would it?

    (this is all doable, because my sail is still on the way)

    Last modified: 15 Mar 2017 08:58 | Anonymous member
  • 15 Mar 2017 08:54
    Reply # 4667929 on 4556642
    Anonymous member (Administrator)


    Jami,

    here is the link to my Frøken Sørensen sailplan (dimensions on p.2). The 22mm battens are a bit on the light side for batten 1 and 3, but otherwise I hit quite well.

    I have made three yards, so far with two tubes on top of each other. I aim for a main tube which should be almost stiff enough to cope alone, and then I add an upper tube from the same dimension as the lower battens. This has proven to hold up well without getting too heavy.

    I tie the halyard to the yard with some sort of rolling hitch. After a little practice, I have found it easy enough to keep the yard from twisting on its side. However, I would not make the yard from two equal tubes, as it will be too weak sideways (or too strong and heavy vertically).

    I only bolt the two tubes together at the ends. This is where they take up most shear forces, and besides, I don’t want to drill big holes near the middle of the yard where stretch and compression is highest. In fact, any holes in the yard is closer than 50mm from the ends.

    Arne


    Last modified: 15 Mar 2017 09:13 | Anonymous member (Administrator)
  • 15 Mar 2017 08:54
    Reply # 4667928 on 4666358
    David Tyler wrote:

    ...the use of a span, attached to the 1/3 and 2/3 of length points, reduces the demands on the tube.

    Sorry David, but I'm not familiar with the terminology here. Could you be more specific for a dummy, please?


  • 15 Mar 2017 08:52
    Reply # 4667924 on 4556642

    Ok,

    seems like I have to think the yard thing over. 

    (Too bad I have already paid for 12 meters of 35x1,5 tube. With 2980mm batten lentgth one 6m tube wasn't enough for my intial plan, because of the longer batten 3 of Arne's Johanna-type sail. Now I seem to have about 10 meters of 35x1.5 tube that I have no use for. Anyone want to fetch from Finland :D ? )

    Last modified: 15 Mar 2017 08:53 | Anonymous member
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