Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[mark69]

Hi all I've been building my yacht for some time now and now I do need some help ,all the deck beams are in and I'm working on the combings and cuddy roof ,but before I add the deck I would like some advice on how the fit this out with the winch servos and relevant blocks ,as I'm after a true scale look I don't want a foresail boom ,all other deck fitting I have done already ..thanks ...mark

[PICKETBOAT]

Mark69


How about a few pictures to give us an idea of the vessel and the internal space/arrangements. That way someone might be able to help. Are you committed to a winch? Sail arm servos are a lot easier to set up and connect, with far less chance of something "jumping off a pulley" and causing a big problem. Just an observation.

[mark69]

Hi picketboat I don't think I'm short of space in the yacht!! what I'm after is ,able to control the Genoa as per full size boat ,I think I've found a way now but I'm not sure on main sheet ,maybe I will lay a drum servo on its side and use a 2-1 purchase through the traveller beam any ideas

[PICKETBOAT]

Mark


I'm impressed. Nice yacht. She will sail wonderfully when finished.


I'm a big scale sail fan so would follow a build like this.


I don't know if any info I give will help but some of it might "light up a spark of an idea".


The pictures show a brigantine I built which had two sail arm servos (one for main and fore sail and one for fore stay, jib and flying jib) and also a home built horizontal drum winch, controlling the yards on the fore mast.  The sail arms overlapped, to save space, but were isolated from each other by a clear plastic sheet. This stopped the loose sheets getting tangled. This is very important.


The sail arm servos were just standard sized (metal geared) servos. Use a more powerful or bigger servo for longer sail arms or big sail areas. They and this set up have worked without fault for years. The hull of this model is 600mm to give a sense of scale.


The horizontal drum winch is also using a standard servo, but it has had the pot (potentiometer) disconnected so that it continues to run in either direction unless the transmitter stick is centred.  On the end of the drum is a simple adjustable spring clutch. This means the winch runs till the sheets pull tight then the clutch slips so nothing gets broken. The gears (from a kids toy) add power and slow the movement down to scale speed. The little black vertical cylinders each contain a lead fishing weight which pulls any slack out of the sheets and stops the drum getting all tangled up. Looks complicated but is simplicity itself. The Tx control stick for this function must retain the return springs so that it self centres and therefore stops the winch. One side of the drum "pays out" while the other side "gather in".


I built this as a self contained unit so that it could be bench tested before fitting. Again it has worked faultlessly after some minor adjustments.


I hope you can make sense of all this rambling. It might be that a horizontal drum winch like this could be adapted to your needs. 


Good modelling. 

[mark69]

Hi thanks its 68" long about 1/6 scale to the full size I'm building this as a display model as well as a fuctional model what I want is a best attempt to make a traveller beam that works in the same way as the full size ,I have been working on some drawings with a few double blocks to make a purchase system I might get away with it ,I like the servo drum as because the moment of pull is close to the servo there is less chance of it stalling  and they are 10..5kg 6 turn ,I've pulled a servo slave out of my aeroplane so I will be able to control the speed I think I've explained this the best way I can ??? .mark

[PICKETBOAT]

Mark


Wow that's big. Much bigger than ANYTHING I have experience with. Yes you are probably on the right track with the servo winch. Sails on a model this size will stall anything less. Can't offer much helpful advice as I am out of my depth with traveller beams!!!!!
Good luck and I shall keep watching. This model is going to need some serious ballast.

[mark69]

Hi its going to be a long build !! The real yacht has a 1tonne keel I will be using lead shot mixed with resin ,there is a equation for this somewhere ?? but that's a long way off prob won't Finnish it this year !!
.....mark

[malcolmfrary]

1:6 scale weight - 6*6*6 = 216.  1 tonne = 1000Kg, divide by scale weight figure, 4.63Kg.  That will float it at waterline, but the weight will probably need to be lower (or reduce the sail plan early) because the wind speeds that the model experiences scale upwards by a factor of about 2.5 for 1:6 scale (square root of scale).

[mark69]

Hi thanks for the equation I've worked in a threaded block at the bottom of the keel for an extension ,the sails are going to be scale made from the company who makes ours !!...mark

[PICKETBOAT]

Mark


What about putting in say 25 or 30% of the ballast (the bit right down at the bottom) as fixed ballast, as you suggest lead with resin binding, and the remaining ballast in sewn up ripstop bags inserted at pond side. That way you are less likely to give yourself a hernia getting the thing in and out of the car/van/pond. It would also give you a chance to fiddle about with the positioning of the ballast to trim the model for performance or scale effect. You should think about this now before installing winches etc so as to allow access.


 The thin ripstop (Kagoo fabric is good) bags should be sewn closed and sewing a strip of Velcro along one side ensures they don't shift position while she is under way. Don't make the bags up with cotton which will rot when wet.


Just observation as I'm sure you have your own ideas.

[mark69]

Hi I may have to mold the lead into the keel well so l can remove it for transport its going to be  heavy .