Catamaran relied on DUO425 plans

[pulsar]

Hi,

I buy plans of cat one year ago.

Shape of hulls and rudders are made acc to plans. Hulls structure and everything above deck is modificated acc my ideas and enginnering calculation.
Total lenght 4250, width 2200, sail 9,6 sqm.
I launched it last sunday. There was wind about 3B (cat speed in my opinion was about 6-8 knots).
I must admit that I haven't nothing in common with sailing, even I've not been on boat or yacht before. What I want to say, that is worth to fulfil dreams.

If you have any question, please let me know.

Best regards
Pulsar

Pulsar, congratulations on sailing your dream! Looks like a neat concept and you appear to have done a great job. Happy Sailing!

[Munter]

You could safely pull on a lot more downhaul. That should help get the rig a little closer to its design shape. Windsurfing rigs usually take large amounts of downhaul.

You've got an intersting concept for supporting the rig!

[pulsar]

Some ideas I took from iceboats.
http://www.isabella-iceboat.com/

I will a little bit modify mast, rudders and find proper shape of sail.

Some people ask on forum about cost of builidng cats. I think that it could take c.a. 1500 euro (with tools to build it). (I made a lot mistakes so it was a little bit more).


BR
Pulsar

[grob]

Pulsar,

I have used a similar rig on my boat, except I have gone for a two windsurfing rigs in a biplane format. see www.fourhulls.com. I am interested in how you joined the windsurfing rig to the sub mast.

How did you find tacking the boat?

I agree you should go for more downhall.

All the best

Gareth

[pulsar]

Hi Gareth,

We mailed about one year ago. I like your boat.
To join both mast I used two clamp(dia70 dia50).(I used them also to connect hulls with croos beams). The bigger one is tightly install on sub mast. Windsurfing mast can rotate in the second clamp. This solution is for now. It doesn't look nice, but works good and can handle big forces.
For the future I want sub mast with hinges on bottom and top with support for windsurfing rig. It should look like door hinges.

Tacking the boat. hmm it was my first time at boat... but...
I make mistake with putting middle point of sail and middle point of hull (forgive me not knowing right names). MPoS is about 1000 mm before MPoH looking forward. Aft part of cat has tendency to turn against the wind. It isn't a problem. Little corection with rudder and it's Ok. As I notice It quite good sail about 45deg against the wind.
Turning with wind is ok but against the wind cat stops, but I have some conception to work it out.

What is your boat weight and dimension?

BR
Pulsar

[grob]

I remember you contacting me now, you sent me a link to a duo which also used biplane windsurfing rigs. Well done with your boat.

Don't be discouraged by the tacking, many cats are difficult to tack, especially those without jibs. Look up roll tacking a catamaran http://www.thebeachcats.com/Article73.htm.

It is hard to see from the pictures but if it is possible to rake the mast for and aft you could try experiment with that.

My boat is 5m long, 2.2m wide and weighs 100kg, did you get yours under 80kg as you hoped?

All the best

Gareth

[Damon]

Originally Posted by grob

Don't be discouraged by the tacking, many cats are difficult to tack, especially those without jibs. Look up roll tacking a catamaran http://www.thebeachcats.com/Article73.htm.

That article url needs an l at the end.
Try
http://www.thebeachcats.com/Article73.html

Good luck, practice practice. Make sure and go into the tack with speed, and not sailing too high going in.

[pulsar]

Unfortunatly I didn't get good weight. Total is 130 kg. To much putty and to heavy glass mats, epoxy also. It could be minimum 40 kg less. I put also double thickness of decks...

Now I'm thinking to start with project of aluminium hulls. Each one is folding from two parts...(conception similar to yours).
I'll rake the mast and try my conception for tacking... everything depends on weather now...

BR
Pulsar