Model Boat Mayhem - Forum

Dry Dock / Shipyard: Builds & Questions => Yachts and Sail R&D: => Topic started by: kiwimodeller on October 26, 2011, 10:46:32 AM

Title: Controlling sails of an Arab Dhow
Post by: kiwimodeller on October 26, 2011, 10:46:32 AM
A friend has built a model of a "Boom Safar" which is a type of Arab Dhow. It was described in Model Shipwright issue 100 but the author of that article decided only to control the rudder. My friend would like assistance to find a way to control the sails with a winch or arm servo. The main problem will be that the sails overlap each other by a considerable amount. Any suggestions most welcome. Thanks, Ian.
Dont know how I managed to post this twice, I got a "Time Out" message the first time. Perhaps one of the Moderators can remove this copy. I could find a "Modify" button but not a "Delete" one. Thanks, Ian.
Title: Re: Controlling sails of an Arab Dhow
Post by: Tug-Kenny on October 26, 2011, 11:36:17 AM

As an aside to your thread, when you get the modify page up, you can then delete the words and replace them with new ones.

Of course, after about half an hour you cannot get the modify button at all. This is where we come in to help.

As a matter of interest, I too would be interested in the answer to your question.

Hope this helps,

Ken
Title: Re: Controlling sails of an Arab Dhow
Post by: tigertiger on October 26, 2011, 12:47:03 PM
There is thread on lateen rigs here, related to a Dhow.
http://www.modelboatmayhem.co.uk/forum/index.php?topic=4059.0

I was looking at one sail, but with two the issues multiply.

I still haven't built the dhow in question, and so I never tested my ideas, but changing tack would have required two channels and some clever pulley work.
Title: Re: Controlling sails of an Arab Dhow
Post by: tigertiger on October 26, 2011, 01:00:03 PM
or you could cheat

Instead of trying to have both sails on a good tack (and then changing tack), have each sail on opposite tacks, and forget tacking the sails.

Then you could do as you can do for overlapping headsails.
See
Reply #6 here http://www.modelboatmayhem.co.uk/forum/index.php?topic=8009.0
And reply #10 here http://www.modelboatmayhem.co.uk/forum/index.php?topic=1685.0

These might be 2 simpler alternative solutions.
Title: Re: Controlling sails of an Arab Dhow
Post by: Jimmy James on October 26, 2011, 01:07:29 PM
The easiest way is a sail arm servo and fix the yards on opposite sides of the mast the way french luggers are rigged ( Check the thread 18 Century lugger in Yachts & Sail R&D)
 this is not ideal but about the best you can do with a lateen rig ...is she an Arab Lateen or a Settee lateen ???
 If you can post some photos it would be easier to advise you
Jimmy
(http://s4.postimage.org/gyjsb793t/W_H_port_side_2.jpg) (http://postimage.org/image/gyjsb793t/)

(http://s3.postimage.org/7n11aywwv/amati_le_Coureur.jpg) (http://postimage.org/image/7n11aywwv/)