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Time to get junk rigged!

  • 01 Jul 2015 15:25
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    Reply # 3415633 on 1414460
    Deleted user

    Do you have the fabrication and design details of your hinges somewhere?
  • 30 Jun 2015 01:02
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    Reply # 3409170 on 1414460
    Deleted user

    Congratulations Oscar.

    The  video 'First Sea Trials' made me envious, Venus, the music ...perfect.

    The sail is nice too! I like the low yard angle, allowing the sail to hang naturally without cranking in a THP and LHP.

    It all looks and works beautifully, well done.

    Sail cloth looks like polyester sailcloth, not odyssey is that correct?

    Let us know how your trip home went.

    Ash

    Ps: May I  request a few leech telltails before the next video please? Thanks

    Last modified: 30 Jun 2015 13:21 | Deleted user
  • 29 Jun 2015 00:00
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    Reply # 3407995 on 1414460
    Deleted user

    Great work! The sail looks really good in your video. It will be interesting to hear how you get on in stronger wind conditions. If you are lucky the sail will work well from the start although most of us seem to spend  a few months sorting out design issues with our new sails. I definitely like the potential of these taller aspect sails with the very short yard and revisit of the hinged battens idea. Maybe a new direction for the junk rig. It will be good also when we get a report from David Tyler of his experiences with his new rig in a variety of sailing conditions.

    Last modified: 29 Jun 2015 00:03 | Deleted user
  • 28 Jun 2015 22:32
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    Reply # 3407948 on 1414460
    Anonymous member

    Following in David's footsteps seems to be something that comes naturally to me, looking at this thread and then after that my forays into wing sails. I've now built a flat sail with hinges, pretty much the same David's current one, albeit with battens made out of round aluminium and hinges (double cones) made out of PMO (a.k.a. Delrin/Acetal). You can find the whole (quick) writeup here and a direct link to a Youtube video of the first sea trials here.

    The reason for postponing the conversion this long was me moving from Finland to Estonia (because of work) and I didn't even have the chance to get the boat afloat last summer.

    Huge thanks to JRA's Ben for working things out with annoying shipping companies to supply me with a nice aluminium flag pole. Also big thanks to my dad (Robin on JRA) who built the mast step and deck partner in Finland while I was starting to sew the sail in my garage in Estonia.

    Just came back from finishing my second trial sail and had a close call while coming back to the wharf where I gradually lowered sail to cut down speed and the last panel wouldn't come down unassisted. I had to quickly run up on deck to lower it manually. I had already rigged a downhaul at the 4th batten down from the yard but apparently I need to rig one at the yard as well. I don't see any other explanation than it being because of the short batten parrels, which can be quite tight, but which on the other hand also allow me to leave out both YHP and LHP. Compromises.

    Haven't had any spare time at all the last week but have documented steps of the conversion and will add them to my blog at some point.

    I'm sailing "home" to Tallinn, Estonia tomorrow and really looking forward to it as the sail seems to be excellent, even though I've only used it in ghoster conditions so far.
  • 05 Jan 2014 09:13
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    Reply # 1468110 on 1414460
    Anonymous member
    Thanks guys for all the tips, lots of good stuff to consider.

    I will probably make the top battens slightly stronger, seems like a good safety precaution. I should be able to get T6-6060 aluminum, perhaps also T6-6082 which is slightly stronger (but I have no idea about the price difference).

    At least now I know in which ballpark I am and can should be able to make the batten pockets accordingly.
  • 04 Jan 2014 23:36
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    Reply # 1467980 on 1467701
    Deleted user
    Graham Cox wrote:.. Alan on Zebedee mentioned that if you can stop the top 2 battens breaking or bending, the others will be fine.  I agree with Paul that 40 x 1.5mm battens would be too light.  50 x 1.5mm is stronger, I am told, than the 38 x 3mm tube I use.  Good luck!

    I'd change that to "if you can stop top 3 battens breaking..", our foresail has 80x3mm yard, 1st batten is 50x3, 2nd - 40x3, 3rd to 7th are 40x1.6.  The top 40x1.6 (3rd) is the one which bent, at the mast. Not through misshap, no chinese gybe or anything, as far as I can tell it was just from sailing to windward in 20kts which did it.

    Had a quick look at the numbers, 50x1.5 is twice the strength of 40x1.5 and 40x3 is similar to 50x1.5. You're lucky if you can get T6 in those sizes, not available here, ours are T5 which is weaker.
  • 04 Jan 2014 12:21
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    Reply # 1467701 on 1414460
    Anonymous member
    Hi Oscar.  I have a 35 sq m sail and broke my yard on my first offshore sail.  It was 60mm x 1.5mm, sleeved in the middle third, giving a 3mm wall thickness.  I knew it was a bit light but thought I'd see it flexing if I was overloading it.  Instead it just snapped suddenly, BANG!  I then fitted a 100 x 3mm yard and have had no further problems.  When I broke the yard I badly bent the top 3 battens, which were 38mm x 3mm by 4.7m.  I was able to straighten them however when I got ashore and am still using them.  Straightening them while at sea though would have been difficult.  It took a lot of force and a sturdy fulcrum.  I have often thought of making the top two sheeted battens a bit heavier.  Alan on Zebedee mentioned that if you can stop the top 2 battens breaking or bending, the others will be fine.  I agree with Paul that 40 x 1.5mm battens would be too light.  50 x 1.5mm is stronger, I am told, than the 38 x 3mm tube I use.  Good luck!
  • 03 Jan 2014 03:06
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    Reply # 1467059 on 1466915
    Anonymous member
    Oscar Fröberg wrote:
    IProposed configuration:

    Battens: 50x1.5mm
    Yard: 80x2mm

    This package would weigh ~30 kg.

    Lighest option I can imagine:

    Battens: 40x1.5mm
    Yard: 70x2mm
    Battens 50x1.5 T6 good! 40 is likely on the light side for you. Your yard, I'd say is on the light side. I'd go for at least 80x3 T6 and 90 or 100x3 T6 would be better. For the yard I do not like less than 3mm wall thickness as the thiner walls are just not mechanically robust.

    There is no need to go for the lightest possible option when doing yards and battens (unless you have a very tender boat) too light and the sail does not come down so readily.
    Last modified: 04 Jan 2014 18:48 | Anonymous member
  • 03 Jan 2014 00:03
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    Reply # 1466943 on 1414460
    Deleted user
    I have one bent batten after less than 200Nm sailing and it was one of the 40x1.6mm battens, 3.9m length. When I made an attempt to straighten it I was surprised how soft it was (T5 aluminium), I couldnt straighten it sufficiently anyway, as the rest of the batten was like a noodle..  I think 40x1.5mm is too light for our 24m2 foresail, fortunately most of the rest  are 40x3mm and will eventually replace the remainder of 1.6's for that size.

    My yards are 80x3mm for the foresail (24m2) and 100x3mm mainsail (30m2), wouldnt dream of going smaller than this.
     

    Last modified: 03 Jan 2014 00:11 | Deleted user
  • 02 Jan 2014 23:29
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    Reply # 1466915 on 1414460
    Anonymous member
    I've now done the easiest part; the yard sleeve and the top four flat panels are cut and next in line are the lowest four panels with lenses/shelves giving camber increasing from 2 to 6% in the lowest panel. And the batten pockets. And all the other small details. It's relatively hard doing this for the first time, thinking through everything twice at every turn, trying to make sure everything will work out in practice. But I have gotten a lot of help from my dad who is simultaneously making new sails for Vanharouva.

    I'm sewing the panels from dacron using old sails and using David's proposed 30 degree angled shelf foot method mentioned here with 50% of the lens camber cut out from the panels.

    Regarding the batten pockets, I should probably settle on some kind of batten dimensions. Proposed configuration:

    Battens: 50x1.5mm
    Yard: 80x2mm

    This package would weigh ~30 kg.

    Lighest option I can imagine:

    Battens: 40x1.5mm
    Yard: 70x2mm

    But the strength of the 40x1.5mm is just ~62% of the 50x1.5mm battens and the weight savings is only 5 kg so I think I'll aim for the former option. The question is then, is there a middle way, and/or should the top 1-2 battens be a little stronger compared to the lower battens? Could the bottom 2-3 be lighter? And what are the merits of using a stronger boom?
       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

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