RC India

hi!
as some know, i like to sail. i was wondering if it is possible to make a rc sailboat, based on either a laser or a hobie 16 (to scale)

http://www.canadiandesignresource.ca/officialgallery/wp-content/uploads/2006/05/laser_canadian_design.jpg
http://cdn1.hobiecat.com/digital_asset_profiles/hobie16-action-00-full_jpg_1600x1600__generated.jpg

what type of servo i will need to control the mainsheet/mainsail ?
also, what battery can i use, because there is no motor involved, how much time on the water can i expect?

thanks!
aniket

Size of servo will depend on the size of the boat and the area of the sail involved. Also you must factor in the kind of wind that you will be sailing in. Standard LiPo batteries may be used. You should get sailing time of more than an hour on a 3S Lipo.

Hope this helps.

for a 15 " sailboat - you can get away with using a standard servo if using a 2" servo arm- if you can
modify for 360 deg rotation and attach a drum - then that same servo can control the sheeting for
upto 24" hull length.

all above is approx but on the conservative side.

i have seen sail boats they are awesome !!!
best of luck sir !!!

@VC sir yup! i guess i can happily use a 700-800mah then.. have to keep it thin because the cat has to be balanced... also plan to sail it in around 5-6 knot winds....
 @saikat the hull length will be around 30"....
@RAZZER i'm 16.... please don't call me sir! -_- :P XD

30" is a big boat - too big for first time.
You will need a sail winch servo - about 10 dollars at HK

Most common problem in sailboats is if you get
stuck out in open water

another alternative for sheet control is use a brushed 280 size motor
with a reversible esc.

This will give good torque without buying a sail winch servo

For Main sail about 12kg-cm torque and for Rudder 5-6 Kg-cm torque servos are required.  Hitec or Eurgel (water resistant) servos  (sail winches)are very popular.

thanks maharana sir! ok so now i got the control settled, any suggestions on what can i use for the sails?? will plastic work? i also have a real sail made of nylon for the enterprise class lying at home :P i can split it and use it otherwise, but looking for something soft, thin and strong, and waterproof...

also, will i have to contruct a balancing sytem of sorts? like on a real boat, we hike out to keep the boat stable and oppose the wind pushing the boat down on a beat or reach... will i have to construct something like that here? like a weight mounted on a servo, that swings side to side

 thanks!
aniket

This is a very interesting thread. Good luck with the build!

Aniket, Why don't you use that material from which raincoats are made? Adiboy made a hovercraft skirt from it and it was a success. If it can work on a hovercraft, might as well work as a sail....Fits the bill perfectly... ;)

For sail use laminating film - it is thick mylar with adhesive on one side.

cheap ubiquitous and works better than fabric 

@saikat and veloci, hmm that might work, though I found something better... it's that material windcheaters are made of.. It's just like a scaled down sail fabric! ;D also If I wipe it with a little vaseline then water doesn't even hold on it... it just glides of!

also I did some reading and found out that if I build single hulled boat instead of a cat, then I can build a weighted centerboard which will prevent it from capsizing...

also I was thinking, would it be wise to put a regular servo to control the sail sheeting or should I invest In a sail winch... because I have a very tight budget and a sail winch costs about 2000.... :/ also I dropped the boat size to about 20" hull length
should I include a gib sail or should I make it a single sail?

thanks
aniket

Sent from a potato using a lamp

Aniket, Windcheater = Raincoat  ;)
I wasn't clear. My bad.
Btw, nice idea of using Vaseline  :thumbsup:

@veloci when you said raincoat, i thought those plasticy ones.... i found a fabric shop over here... he keeps! ;D
any ideas on wether to include a foresail or not??

thanks!
aniket

That windcheater fabric is called Ripstop. Almost the same as the car covers. I used it to build the Hovercraft skirts.

@VC sir, cool, now i know what to call it while sking around :thumbsup:

Use a jib - it looks better aesthetically - practically - not
much difference.

@saikat :thumbsup: let's see now... any suggestions on what to use to make a weighted center board?

thanks!
aniket


Sent from a potato using a lamp

You can pick up lead weights practically free from the guys who balance car wheels and align them.

Instead u can u use a weight bulb / keel.

I used a cast iron keel weight on my RC bermuda rigged sailboat. Sand cast the weight and then machined it. It was fixed to the hardwood keel using 2 X 3" long brass wood screws and then epoxied.
As for the sail controls I used winch arms 130mm X 20mm made from 1.5mm thk brass sheets to winch drums where you either need a winch servo or need to modify your existing standard servo.
I used a pair of futaba servos with metal gears for the sail winch & rudder.

happy sailing.
Nilanjan Paul

Tanmay its a year old thread, please see the date the thread was created before you post.

RC Neil, Posts serve as references for some later on. His advice might be too late for the respective poster of the initial thread, but would be helpful to a newbie trying out the same build with limited resources.
"just saying"

hi i have a micro magic sail boat from graupner  height is 1 mtr and hull length is 550 mm and all weight is with radio is 950 gms and i use standard servos for sail and rudder control