Hi all,
can any of you tell me if putting a square top on a nacra 5.2 would be a worthwile add-on?
I will need a new main some time next year and I want to build it myself (I own a heavy duty walking foot zigzag sewing machine, a clone of the sailrite LSZ-1).

I'm looking at either getting a kit from sailrite or designing everything from scratch myself. I'm a low budget scavenger when it comes to sailing, can you tell?

I'll probably use dacron (unless someone throws me a cheap roll of pentex), so the material isn't the major problem it may be with high-tech materials.

Would a square top be worth the extra bother. Or would it be a waste to NOT go with a square top considering all the valuable (but fun to me) time involved?

regards,
Dennis

If you want to do it, do it! In relation to the rest of the project of building a mainsail, the square top dont add any extra work or cost. The only cost is in new battens and invested time in figuring out how make it fast both design wise and in real sailing.

About dacron in square tops. You will probably want a radial layout and that is pretty hard to cut by hand without templates (and even then it is not trivial). A crosscut layout will give a lot of forces needing to be transferred on the bias of the cloth leading to stretch and deformation. Perhaps you can find a good deal on some Maxx cloth directly from Contender? That would also save you quite some stitching, especially if you choose to glue the panels together.


What LSZ-1 clone did you get, what did it cost, what are the differences to the LSZ-1 and what have you built with the machine so far? I am in the market myself so I am checking options.

How do you intend to design the sail? By laying it out the old way, Sailcut GPL software or something else?

I would have thought that it would be really tricky to get the leach of a dacron square top to behave. sail would stretch pretty quickly

I guess you are assuming the sail to be a crosscut? A radial cut will handle it OK.

Rolf,
I intend to use sailcut for the design and loft the sail out by hand. Alternative is to ask Sailrite to design and cut one for me. Maybe a better idea to go pre-cut with a radial cut, thanks for that tip!
Or.. I could upgrade to pentex or something and stick with ye olde cross-cut... Easier to fit under the machine...

I have imported a sewing machine from Taiwan, but the machine is unsuitable in its current setup. I can't recommend it due to the crappy electrical system (it is a total joke on my prototype). I have sent the factory details of what is required to meet EU standards and they say they are willing to make the changes and do what it takes to go to full compliance. I'm eagerly awaiting their modifications! If they get it right I will sell them in the EU, but only if everything is 100% A-OK. I'm not looking for trouble, just want to help out other sailors who have small pockets like me.

If you have the money why not get the sailrite LSZ-1. My unit comes close mechanically, but it still needs to be tuned to reach its full potential. I haven't got around to giving it a full tune-up yet. The walking foot is impressive as it is though. I scrounged some Tenara which didn't work well on the industrial Adler at a shop near by, it stitched just fine on my machine out of the box! Also tried some M20 thread and worked fine. I still need to tweak the hook timing to go through more than seven layers of Sunbrella though. It is early days yet and I have only used the machine on test patches and a small sunbrella pouch for my daughter... The real test will be my new trampoline this winter. I think the biggest differences between my machine and the sailrite are the tweaking they do to every unit. Mine still needs that work done. And I sure hope their electrical system is better. I think they are very honest with what they write on their website regarding the differences between the machines. You'd have to check out their patent info to get the details though.

Dennis,

unless you get a pentex cloth with fibers running like they do in the Maxx cloth and it's like (0-90,+-45 and 70 I think, it has beena while) the pentex will distort just as bad as dacron. You need fibers oriented along the load paths and in a squaretop that is hard to to with a crosscut layout. Maxx cloth is pretty well suited. The Maxx Pen09 might fit you, or something heavier. Crosscut is definately the way to go for building from scratch at home. Radial is a lot more work.
Check out Contenders website and give them a call. You might get a good deal on some Maxx for your first deal with them. http://www.contendersailcloth.com/maxx.asp?Sid=3&SHid=530&SWid=1004

Take care with Sailcut. When you e.g. add luff curve , the height of the sail will be changed. What you put in is not what comes out, but is slightly different. On a mainsail this is noticeable, but you can fix it with some creative work with scissors before you put on patches and tape along the foot. For sails that have to measure in, check all dimensions after assembling panels.

Thanks for the info on the sewing machine. As you probably guessed the budget for items like his is ever low. I now have a secondhand Pfaff domestic machine with their walking foot solution. Picked it up for about EUR120 and it has chugged its way through 5 sails by now. It really struggles with patches and thread tension. Runs out of thread on the bobbin etc. but it works. Let me know when you begin to import the Taiwan machines.

Hi Dennis,

I remember that the price difference between Dacron and Pentex wasn't that much, when we asked our sailmaker for a new spi trumpet. However it wasn't MAXX or FLEXX of course.


Right battens are expensive, but so simple that even I could make it by myself (and I don't even have workshop). Feel free to contact me for details.

Cheers,

Klaus

Ah, and go for s square top. A good square top is always better than a pin head sail and a bad square top is still better than a bad pin head sail. You may need a more powerfull main sheet.

New thread perhaps? I would love to hear your thoughts.



Square tops rule

Ok Guys: Square top it will be!
Smiths_cat, any help on the battens is appreciated (I already have a vacuum pump; aka old hermetic airconditioner pump). I would love to hear what you have to say on making those battens!
Separate Thread on Making battens (Please post in this separate thread!)