maandag 18 mei 2009

Rig

A few months ago some of the parts for my rig were delivered. Building the mast was mostly just a matter of drilling and sawing holes and popping or screwing the parts into the mast profile. I made sure not to have any sharp corners in the cutouts, as I've read those will be prone to develop cracks. To insulate the aluminium from the steel I used silicone kit, but it would have been better and easier to use 'duralac' - but unfortunately I found out too late about this product.

The upper part of the diamond stays are anchored with T-terminals. The spanners are on the lower part and need to be attached to a tang. To bolt the tang to the mast I cut two pieces of 1 cm thick alu:


Using some solid electricity wire it's easy to drag the piece to its location....

Below the piece is bolted in place. The hole in the middle will be tapped to receive the short M8 bolt which will hold the shroud tang.
I've always tried to avoid marine shops. In my opinion they charge outrageous prices. The last time I had to go there I saw a blister ordinary type 304 nyloc m5 nuts being sold for 1 euro (about 1 dollar) for each nut. I had just bought a 500-box of exactly the same nuts at an online materials-shop for about 10 euro. Maybe most people owning a sailboat are so loaded they don't care what to pay. Or maybe they think they get superior quality, because why else would this small nut be so expensive?

Anyway, to save myself the anger of having to pay 30 euro for two tangs, I bought a strip of 4mm stainless steel for less then 1 euro and worked maybe 10 minutes:

(1) Saw two pieces and drill four holes,

(2) slam each piece two or three times with a hammer, and
(3) file the edges a bit so they're not sharp. End result is for sure not as polished and good looking as the shop tang, but it's good enough for me and I've saved the earnings of working for more than an hour at the office in 10 minutes.
The setup of the mast will be as simple as possible.
I'm thinking of putting in halyards for only the main sail and jib (jib with 2:1 halyard). The halyards exit the mast high, so I can raise the sails by hand. All lines stay only on the mast. The idea is to raise the main by hand, fix the halyard with a stopper, and then tighten the main by pulling a tackle form the mastfoot to the eye at the bottom of the sail.
Maybe I'll attach a fixed rope as a backup forestay, also because this is easy for raising and lowering the mast.
The only expensive cleat on the mast will be the stopper for the main halyard. It is bolted to a tapping plate I made of a strip of 4 mm stainless steel. Because the mast is not flat where I need to mount the stopper, I put a piece of cutting board between the backing plate and the mast. The idea is the cutting board will set to the shape of the mast and prevent point loads of the steel backing plate on the mast.
The stopper was installed using the 'copperwire' method I've shown above.
Erik Precourt mailed me he is working on a version of a bigger version of the Olivier Link for 8 mm lines, but this one it is not in production yet (pictures of the smaller links can be seen on http://www.precourt.ca/). Seems to me the perfect way to attach the shrouds. I'll splice them directly on the links. Clean, easy, light and probably very strong as the link will only pull on the mast from inside and not through bolts. Problem is: will the links be available fast enough? Else I will have to go with the plans, buy the wichard padeyes, make the backing plates and the epoxy pads etc.

The only thing to do is to weld in the mastfoot. More about that later on. I've got the welding machine at home, now I only need the skills to use it. So I'm already halfway there.

3 opmerkingen:

bucko00014 zei

Hi Menno , have you thought about a 2:1 main halyard as well ? Halves compression load on the mast and jammer and lets you use a thinner line . Jammers tend to let the slippery core of modern ropes slide under high loads which transfers the load to the casing which then fails . Bonus is you don't need an expensive block on the mainsail head , a nice big shackle with rounded corners works well .Cheers , Jim Buckland .

Menno zei

Hi Jim
Thanks for the tip.
I hadn't thought about it. I was only thinking of the force needed to raise the sail, not about the compression nor the loads on the jammer. Sounds like a good idea but... to do a 2:1 setup on the main I need to buy new (more) dyneema, so I'll probably start with my original idea and see if it works for me (cruising with family, so most of the time no high loads for me).
In time I might switch.

bucko00014 zei

That is probably the best way to go . If you find you need to change it is very easy to do later - the cost of the halyard is the only real expense .