smallest RC/sailboat plan

[cosmo]

where can I found plans or/and photos of the smallest RC/sailboat in our hobby?
Now the access to the micro/mini stuff is more easy so, why not not a mini/micro SAILBOAT for small places?
TIA.

[Climate]

Anything smaller than 30 inches, just is not going to work well.
Its that simple. The dynamics are not there for a hull under 30" length.
If you want to get in to hydrodynamics and the theory of waterline length vs displacement I would be happy to pass a copy of my 243 page thesis on the subject to you.

Peter

Visit www.climatemodels.com

[cosmo]

oops, I don-t know that...thanks for the link.
Cosmo.

[steelhead]

Sounds fun, but it I havent had much luck with anything under 20 inches even as far as a non rc pond sailer

Dean

[The Enemy]

climate,

Would you be willing to summarize why it wouldn't work? (sounds quite interesting) If its too long, I'm in Guelph and would love to be able to discuss my boat. (well, sailboats in general)

Thx
Enemy

[Climate]

It is not that a small boat will not work, it is just that it will not work as efficiently as a longer or larger boat.
As a boat moves through the water, it creates a wave, or series of waves along its length. The wave is actually the water that has been displaced by the hull as it moves through it. The longer the hull is, the less the water being displaced is pushed up on to the sides of the hull and the more it is trailed back along the length of the hull.
A boat with a given displacement must have an equal (or greater) volume of air inside its hull in order to maintain its existence on the surface. If 2 identical displacement boats are made, one with a fat short hull, and one with a long skinny hull, the short fat one will displace water faster around the hull at a given speed. This creates higher drag and a large, high wave.
The skinny hull will have a long short wave, with much less resistance on the hull as it goes through it.

It is like comparing a rowboat and a canoe, both weighing the same. The canoe will travel further and faster given the same amount of power acting to propel it.

Since liquid can not be scaled in its viscosity to match our models, the lighter smaller boat must work harder to push its way through the water than the larger boat. The magic numbers for hull efficiency start at around 30" in length, and 5-7" wide.

You will notice that there are many classes of boats that are specific lengths and widths. This is because testing has shown these measurements to be the most efficient.

Hope that helps clear it up a bit.

Peter
Visit: www.climatemodels.com

[The Enemy]

Excellent explanation. Thank you very much. http://66.227.101.70/contrib/edoom/hideing_behind_computer.gif

Makes sense. Bummer though. I would really love to have something extra miniature for those trips to the little lakes in the Canadian Shield.

Enemy

[steelhead]

I say make one. I've made a few pond sailers that "worked" just not great. Perhaps your the one to find a new hull shape for the yaching industry.


People told mr and mr wright that man couldnt fly in heavier than air powered vehicles.


Dean

PS- tell us how it workes out

:)

[The Enemy]

I surely would if I had the time. http://www.gamers-forums.com/smilies/contrib/dday/nope.gif But I don't. Sorry. 2 jobs, karting, flying, and my girlfriend take most of my time.

The Enemy

[dgoebel]

Enemy,
I'm sure a footy would be small enough to pack in anywhere, use's regular servos (probably could use some smaller servos, and only needs a 2ch tx)

All the Footy sailors I've heard of just love them...

http://homepages.ihug.co.nz/~bsmack/

Attached pic (that's one foot long...)

[The Enemy]

OMG! I gotta have one....

Thanks for the heads up!!

Enemy

[steelhead]

well now- thats a 12 inch hull. im wondering how "well" it works. Looks awefully fat and squatty.
I like his 540 design. Much like my mini soling

Dean

[cosmo]

Thanks again, This sailboat looks great!

[losiXXXman]

Hey Climate,

Nice discussion of the hull thing. I'm not formally trained in hydrodynamics, but did study mechanical engineering for a while. How about this idea though.. if someone wants something smaller than 30 inches, couldn't a planing hull work? For that matter, are you or anyone else aware of any sail powered planing hulls in the RC world?

[micro sailor]

people told me a 12 inch yacht wouldn't work ....But after 2 years of messing around with them I discovered a formula that works,using standard radio and AA batts to boot.
So anything is possible.
I am working on other small models at present too.
You would be amazed at the performance possible.
Looking to use micro r/c equipment and higher tech materials in my next generation of "Footy" class yachts as well.
micro sailor

[pompebled]

Hey Climate,

Nice discussion of the hull thing. I'm not formally trained in hydrodynamics, but did study mechanical engineering for a while. How about this idea though.. if someone wants something smaller than 30 inches, couldn't a planing hull work? For that matter, are you or anyone else aware of any sail powered planing hulls in the RC world?

Yes, there are, I have to look for it, but a while ago I found a site with planing sailboat models (a cat, if I'm not mistaken), very, very fast!

When I've found it (again) I'll post the link.

Regards, Jan.

[losiXXXman]

I think it would be cool to make a model of an olympic racing dinghy. Even if you have to use a counterweight at the bottom of the centerboard, its not visible when sailing anyway. Of course the extra weight makes it more difficult to get on a plane...I'm only now building my first sailboat, but would like to experiment with such a thing in the future.

[mrfirkin]

I like the look of this Footy,

I gotta try one as well.

Paul. :)

PS,

Who cares about hull design and all that boring theory if it sails nice! :p

[Ghost 2501]

there is a good RTR yacht availaible, the graupner southampton

[micro sailor]

when I googled for graupner southampton...I found a tug not a yacht.
micro sailor

[Joules]

Are these the olympic planing hulls you refered too.

http://www.aquataurmodels.com/index.html

Joules

[Vinnya42]

HEre is my newly finished footy, it is 14oz and the hull is made of 1/32" basswood.

[Spadinator]

Looks Good!!!! I am planning to start a Footy soon!!! How difficult was the build?

[lrsudog]

After building a couple of smallish (10"-14") R/C sailboats from plastic model kits, including a pseudo Bluenose schooner, IMHO, it's the sailing site that is more important than the size of the model.

It seems true that very small hulls will not perform as well as larger hulls, but I think it is actually the bad quality of the wind close to the surface of the water that is the major problem. I think the larger sailboats just have more sail area up further into the breeze that is less disturbed by the water surface/air interface.

I've sailed my little boats in a few places where, because of the local geography, the breeze was steady and undisturbed down low. The water was still almost glassy, and the 2-4 MPH windspeed was perfect for smooth sailing. The same windspeed in another part of the lake caused chop, and horrible performance for the boat.

[keven64]

micro sailor said
people told me a 12 inch yacht wouldn't work ....But after 2 years of messing around with them I discovered a formula that works,using standard radio and AA batts to boot.Roger Stollery had a foot-long radio controlled yacht years ago...
Small models ARE possible ;)

The footy looks GREAT, micro sailor ! :cool:
I am just downloading the plans for a Bobabout. ;)

Keven. :)

[micro sailor]

Yes I remember Rogers boat. Called "Choppa" if I remember right.I never recall hearing anything about an r/c version though.
I designed my first 12 inch yacht for a school project in 1982..never thought to radio control one until 20 years later!!!
Got caught up with M and one metres instead.
I have a 6inch r/c yacht that I have just completed.fiddly build but i have done it..maiden voyage soon and pics if it sails like i think it should!!!
I have a hull built for a 4 inch model..getting silly now but I want to see what is possible.
I used to dream of tiny r/c yachts like this as a child..the equipment avalible today makes it possible!
Micro sailor

[keven64]

Hello,

I seem to recall it was called 'Choppa'... or something similar.
I am certain the caption with the photo in the magazine said 'radio', and that his son was stood on the bank 'playing' with it.

I remember * thinking at the time that that was 'not too clever' because my uncle had a 12" model tug that was 2ch controlled...
He removed the geartrain from a micro ( it was micro then ) servo and used it's motor to drive the propeller through a gearbox using the amplifier as a fwd/reverse speed controller...
The other servo operated the rudder conventionally...

*Perhaps it is my mind getting fuddled with old age... :rolleyes:
I am looking into it...

A 'six-inch' yacht would be great to promote model yachting - imagine hosting a race at a swimming pool...

Four inches ? Six inches ?
These are hull lengths. What would the overall lengths be ?

Keven. :)

[beanoman]

if anyone can direct me to a site/post with general information on rc yachts/sailboats, i am sure i could make a easy to build 4 incher. i have a 5 inch landing craft, and it can carry 1/64 rc cars, but i dont know a thing about having sails.

a footy is way to big for me, lol. i doubt i could even build something that big.

irsudog is also very correct- we need to "scale down" waves, and wind, for the boat... my micro boats are good in bathtubs, but even in a indoor pool, there is too many small waves.. a inch high wave is like being near a tornado to my boats.

beano

[Ghost 2501]

yes I meant "University club 37" not southampton

[Ghost 2501]

or get the sealite by ripmax

[dgoebel]

Beanoman,
Check www.AMYA.org and stuff like the US One Meter building guide etc... that should help...

[beanoman]

thanks, dgoebel.

well, here is is. 4 inches long, and you can see it on the hull... i used plastic from a ruler to build it. i know that might sound cheap, but it is .5 mm thick, which is just the right thickness. also, it builds... slightly fast. second pic also has the rx i will use.

im out of carbon fiber at the moment, so i will use a 1mm thick fiberglass rod as the mast.

beano

http://img.photobucket.com/albums/v318/beano/yacht1.jpg
http://img.photobucket.com/albums/v318/beano/yacht2.jpg

[micro sailor]

beanoman,
Your hull volume looks extremly small,Your electrics will have to be lighter than that shown to make this hull sail.
also 0.5mm plastic will be to heavy,your hull must weigh a few grams at least already.
Just looking at your hull I am guessing its about 10g total displ.

There is a world of diffrence between a sailboat and powered boat at this scale

attached is my hull.
displ is 25g total..Bit car gear ready to go in...8g for all electrics
10g ballast for the keel..7g budgeted for the hull and rig
This hull is one layer of light glass cloth..it weighs 3grams

Micro sailor

[beanoman]

heh, your using bit car stuff also? lol.

anyways, it floats with all of the wieght... but only just. i mean, the water is exactly level with the top of the hull. so, i am going to extend the hull up a tiny bit.

yours, on the other hand... 25 grams??? wow. mine is projected to hit about 9.5, ready to sail. thats because i used my ultra top secret method, that i thought of yesterday, lol. wot i did was, seal up the battery with hotglue, and zats the ballast.

8 grams electronics? should be more in the 6.5 range. what battery are you using with it?

my hull is from cheap plastic, and it wieghs 2.5 grams with the keel and mast.

beanoman

[micro sailor]

I considered using the battery as the ballast bulb to..But its not heavy enough.
You really need your ballast bulb to be at least 1/2 your all up weight to get decent sailing performance.
I have hacked a snowglobe bit car..built a linear actuator for the rudder and will use the cars drive motor and gearbox as a "sailwinch". I am using the cars battery 1.2v / 80mah
Mine floats on its lines nicely with 25g all up..nice ballast ratio,bet it will sail not bad.
Fun project.
Micro sailor

[beanoman]

i was thinking of using the steering coils/magnet for the sail... i dont know if it will have enough power. i built the part of the sail the can rotate around... i dont know what its called. does the sail need to "center"?

i am building a "deeper" hull now.

benthehen

[micro sailor]

I sailed my proto 6 inch yacht tonight.
It does sail pretty well.I have a few issues to deal with though.The rudder is to small,The rudder on a yacht as small as this has to be surprisingly big it seems.
My Jib pivot is not as free moving as it needs to be..there simply isn't enough sail area to generate the force needed to make it free moving with a conventional setup.
I will fix these problems and try again.
This is a pretty tall order to get the performance I want from a yacht this small.But I will get it I can see that.
The 4 inch yacht is going to be much worse to sort out I think.
a few pics later maybe if I get time.

Micro sailor

[keven64]

micro sailor,

I enquired with the Model Yachting Association here in the UK about the 'Choppa'...

and received an e-mail in reply. :cool:
Now I have Roger Stollery's #number ! :eek:
I will ring him for a chat later this evening.

Keven. :)

[keven64]

micro sailor said
I have a few issues to deal with though.The rudder to small,The rudder on a yacht as small as this has to be surprisingly big it seems.How DEEP are the fin and rudder - 2 1/2" or so ?
Go deeper...

and added
My Jib pivot is not as free moving as it needs to be..there simply isn't enough sail area to generate the force needed to make it free moving with a conventional setup.I'm guessing you may need a swing rig for that...

Keven. :)

[beanoman]

i finished my deeper hull... looks like it should float higher now. can someone explain how the "jib" is moved? i think i am not understanding how its controlled... a good picture would probly help.

i think i may try and build a 6 incher, before i finish the four inch. seems its easier the larger it is.

beano

EDIT: grrrr, its still way to low. i am going to build a 6 incher, then come back to four inch. micro sailor, are you using the bit car equiptment for your six inch long one also? i may have some semi-propo or proportional stuff this small, il have to check...

[micro sailor]

I am using conventional radio in the 6 inch yacht.
Actually the gear I am using is quite heavy(9g servos)But I wanted proof of concept before splashing out for lighter stuff
Yes for sure the bigger the boat the easier it is to sail.Sailing a one metre is a cakewalk after sailing footys..the 6 inch yacht will require all my experience to sail properly..the 4 incher will be dam differcult and I have been at this yachting lark for 30 years!
beanoman you need to start with your estimated all up weight first then work back to design your hull to get the proper displacment.designing sailboat hulls is not easy and involves a fair bit of math and hydrostatics knowlwdge.
If I was you I would start with someone elses plans to avoid disapointment for your first sailboat projects.
Micro sailor

[beanoman]

hmm, can you post what your 6 inch long hull looks like? i would like to see wha it needs to be shaped like to hold that weight. i think i build mine too thin and shallow...

beanoman

[micro sailor]

Here is a lousy shot of my 6 inch yacht.

[keven64]

Lousy shot ? Perhaps...

FANTASTIC yacht ! ;)
Any chance of a picture from the side ?
What weight have you at the end of the fin ?

Keven. :)

[micro sailor]

120g all up weight.
40g on the end of the fin.
Thanks for the compliment!
Micro sailor

[Aerominded]

Micro, et al, what foil sections are you using for the footy keels and rudders? This would seem critical, the smaller you get. :cool:

Thanks!

[keven64]

micro sailor,

Do you know of the full size marine designer Jay Benford ?

That little blue yacht you made has lovely voluminous lines. :)
It puts me in mind of Benford's 14' Cruiser Yacht "Happy" (http://www.amazon.com/gp/reader/1888671041/ref=sib_rdr_next3_ex1/002-4459262-5761654?%5Fencoding=UTF8&p=S003&j=1&ns=1#reader-page)...
It's silhouette is at the top of the page in the link. ;)

The 6" yacht is inspirational work, and with servos, too ! :eek:
I wonder if I could manage a...

Nahh - I'll build a Bobabout... for now.

Keven. :)

[micro sailor]

Aerominded,
Actually I dont belive the sections are critical at these reynolds numbers..as long as they are thin..water is 1000 times denser than air. I usualy use a cats eye type section as thin as practical.
Area and profile shape are most important on these models though.
Keven64.
Yes the volumous hull was nessasary to accomadate the rather weighty radio equipment I had.
The servos are 9 g each.I used a standard Futaba RX with the case removed and 3 1/3AAA nicad cells
I will purchase lighter servos now for the next model.
I made a start tonight on the next one. A 9 inch semi scale AC class yacht.
Would make a good swimming pool racer.
I havn't given up on the 4 inch model either.Might be a bit small though? :)
Micro sailor

[micro sailor]

Made some progress on the 4 inch yacht today.
Rudder and a new keel in place.
actuator installed for the rudder..its is going to be a nightmare linkage with only 2.5mm movement.
0.8mm balsa deck glued in along with the mast tube.
Mast is made from 1.5mm Western red cedar.

[beanoman]

micro sailor, have you considered using the motor for rudder control?

i havnt done much with boats lately. my hobby has switched over to airplanes again. but, i should be obsessed with boats again in a few days... some people have mood swings, i have hobby swings. lol. but, i do have a much more voluminus(lol) four inch hull now, should hold the weight now.

bean

[mr. fix-it]

How about a 12" cat? Or what I am working on, a flattee.

[micro sailor]

Beanoman,
Yes the rudder actuator is not working out to well.
Anyone know how to hook up a 2nd motor to the bit clone boards? (the ones with 2 steering coils)
The standard motor and gearbox is working well for the sailwinch though.
I have some stunt cars that have the 2 motors so may change to that.
I am real temted to build a plane with all this bit car gear too..and a tiny (3inch) speedboat!

Micro sailor

[beanoman]

well, i would say use the stunt car rx... mine have been really great- long range, two motors.

bitplanes are alot of fun, and you are on the website with the most info, and some of the best micro builders... lol.

i have built a 3.5 inch speedboat... it floated decently high in the water. i dare ye to try and beat my 1 inch sub unoficial record, lol. sub is of course nothing realistic looking. the sub is no longer alive, although i may make another one soon.

anyways, i have given up on sailboats. or, atleast untill toys r us is selling kiddy-pools again :). i think a five foot kiddy pool, with a electric fan or two, should work. and, it will be in my basement :).

beano

[iwire]

Try this:
http://home.mindspring.com/~telemark/bluenose/index.html
To quote the builder, "Scale wooden R/C sailboat kits are a dying breed. The future of this hobby may well be represented by static conversions. If this is the case, then so be it. The result is, as always, limited only by the imagination, technical, and aesthetic execution of the artful modelmaker."
Probably had alotta time on his hands...

[micro sailor]

Beano man,
my stunt car gear seems to only have a range of 5m (15 feet) as it came.
My Bit cars have better range.
It will do for starters though.
As a kid I dreamed of sailing scalish looking tiny r/c yachts on an indoor pond.
It will come true soon.
I intend to sail on a 8x4 pond with the base from a plywood sheet.
A fleet of 4 inch and 6inch scale looking racing yachts will sail on this "pond"
great for exhibitions and the like..and long winter days and nights.

Micro sailor

[eerrp]

I recently got interested in sailboats with wingsails (narrow, rigid wings like on an airplane as opposed to cloth sails) because of their incredible efficiency. I got a lot of information (including the following) from this web sight:
http://www.wingsails.com/text.html
The efficiency of sails is usually measured using its drive to heel ratio (DH), which is comparable to the lift to drag ratio (LD) used in airplane wings. To give you an idea of how much more efficient a wingsail is compared to a standard one, a modest sailboat has a 5:1 LD, an America’s Cup boat strives for a 10:1 LD, but the rigid wing used on a sailplane can have an LD of 60:1! Because of their efficiency, boats with wingsails can point higher and sail faster than standard boats. Anyway, during my period of great infatuation with this idea, I wanted to test my own model to see how it works. I rummaged up some packaging foam, a coke can, and a bit of solder and made a 3" long model to test in the bathtub. To keep everything simple, I just hard mounted the sail in one position (set to sail on a closely hauled starboard tack). After a few moments hovering over the bathtub with a room fan (and dorm mates giving me some weird looks) I became a believer in wingsail technology: it worked great! I could blow from in font of the boat and it would come toward the source! Now I'm working on making a symmetrical airfoil (also pictured) that can be adjusted for all points of sail, which I plan to put on a similar sized (but perhaps rc) boat. I too, have a great interest in super tiny rc boats, so if any one can work with this idea, I’d be interested in seeing their results.

[micro sailor]

I have done some work with rigid symetrical wing sails on some of my footy yachts.
Moments of blinding speed and fantastic perfromance..but alas even more momments of differcult trim and slowness.I tried to get it all to work in all about 4 or 5 wings were tried.
I tried some small scale experiments like yours also..I used solid balsa shaped wings.
I have done no more with the 4 inch yacht shown above..hopefully i will get back to it one day.It can be done!

Micro sailor

[wingnut163]

Ahoy Cosmo;
think small. i'm doing a convertion of a plastic model. its a Entex model of the West Wind, a 30' sloop. in 1/20 scale. thats 16" long. i'm using aluminum mast and boom. even put a kicker in it since the real one had it. i'm not finshed yet but i'll let you know how it sails. i all so RCed a 8.5" tug. works great. i'm all so putting a lead keel on it so she will stay right side up
skip

[Mixmaster]

Hi all,

Been making very small yachts for years and have found the following:
-an excellent construction is polystyrene (normal foam) first cut with a razor then sanded with new fine paper. I fibreglass this with the some really light cloth that is barely paper thick just to seal it. To mount you gear just cut straight into the foam...neatly!....All up the lack of discontinuities in the cunstruction makes it very light overall.
-I always use ocean racing yacht hull types as they make the keel more effective....these are the boat with the very wide sterns
-I always make my own winches, mine are smaller, lighter tougher cheaper! They are easy to make, take a normal servo and remove the pot (for the simple version) all you have to do now is shave of the spur that prevent the top cog doing multiple spins and there you go... its really that easy. If you want the deluxe version the get out ye olde multi meter and measure the resistance of the pot, wander down to your local electronics store and buy the same resistance but in multispin. Glue it in and there you go. These winches are tremendously powerful and quite reliable.
-Stay away from aluminum, the heat treatment they use is completely wrong for our requirements making the spars too soft. Always use carbon, for yachts it is stiffness that counts and carbon is very stiff!...go to a kite store, they have everything.
-I use WEST system epoxy due to its stiffness, it also has great surface tension.

By the time you have done all this you boat can literally be thrown in the water and never break or sink. The efficiency of the construction makes it very light compared to basically all other methods.

Cheers,
mix

[Mixmaster]

My smallest boat is 450mm (17inches?) and has a swing keel. when the boat heals one rudder comes completely out of the water which is a nice touch as that is what happens normally. Right now i am builting two match racers, they are exactly the same and are (will be) water proof to 5m or so) so i can race them in heavy weather, these should be much faster and are 600mm long.

[micro sailor]

I have recently recomenced work on my micro projects again.
I am trying a half size "BobAbout"footy(I have posted the free plans here)
Overall weight will be 60g,the r/c system is from a stunt car and weighs 17g.
I am convinced that really small r/c sailboats can be built and sailed,my final goal is 3 inch yacht sailing on a 8 foot by 4 foot pool indoors with fans supplying the breeze.
Take a look in the micro planes section,those guys are flying 4 inch span models,I think the same can be done for yachts.

If the half size Footy works ok then I will progress to 1/3 then 1/4 size....

[beanoman]

micro sailor, i randomly remembered this thread while scroling through rcg :)... i think i will give it another try.. going for 4 inches again.

beano

[micro sailor]

Next 4 incher off the production line,not r/ced yet but sailing great on its own.

[micro sailor]

At last!! I have her working,
Test sail this evening under full radio control.Control is positive and managable using the insides from a tiny r/c car.The sail winch is not as powerful as I had hoped and requires some work ,but the boat is working and sailing great.
This was my 3rd attempt at a r/c model at this size,feels good to have finally made it.
Total displacment(weight) is 25 grams,12grams is ballast and another12grams for the entire radio system,the boat itself picks up the other remaining gram:)

[The Enemy]

MS,
That's amazing. Great work!

Are you able to post pics of how you did the sail winch? I have the guts from a small RC car also and would like to try. I was thinking of a drum winch so far... (there are 2 motors, one on the steering channel, one on throttle)

Also, any ideas on how to use the steering motor for rudder? It is exactly the same as the other motor...

Thanks,
Corey

[micro sailor]

Hi Corey,
Struggling with my cheap as camera,will post pics when i can.
For the rudder i am using the motor as is.Like an actuater.Seems to have enough guts to handle the rudder.
I am using the other motor for sail control with a small gearbox and an arm.Its struggling and I will have to either reduce gearing further or try a drum type arrangment.
Its a real stuggle to get everything working well.For example on the rudder lingage the output arm is 3mm long.
I am very close to acheiving backyard sailing.....can't wait

[charlieuk]

i might try using two gearboxes of the stering one for a drum winch and the outher for the ruder.i did a rc place from one of these with no mods to the eletricks and it was amazing to see it fly.i also tried the gearboxes on a lot larger glider and that was fine to.ill nock somthing up and let u know

[The Enemy]

MS,
Cool, thanks. No rush, I appreciate the pics no matter when you can post them.

Charlie,
Sounds great. When you're slapping something together can you let us know the issues you encounter. That way I'll know what to expect... Thanks.

Corey

[micro sailor]

I would have used the gearboxes from the car as is.BUTthey are way to heavy and there isn't enough room in the hull for them.
I could change to a LiPo cell to save some weight.I am using the 1/3 size cells that came with the car.
A slightly longer hull with the same volume is where I am headed for the next one.4 inches is just to differcult to trim.

[steelhead]

...pulling out my old hull patterns for a 9 inch r/c sailboat again...

Dean

[micro sailor]

7 inches long.
40g overall weight
Sorta semi scale IOMish look to it.

should make a nice pool sailor.
Looking fwd to splashing this one,Have learnt quite a bit recently about hydrodynamics at this micro scale

[micro sailor]

Rigged and ready for first tests.

[Bob Starr]

Brett,
Looking at your picture, is that some sort of offset mast? Some really novel ideas there! I see no booms either! That boat must be awfully light!
Bob

[tallastro]

Look closer Bob. There are very thin curved booms. They remind me of fish bones.

I like the boat Brett. I can't wait to see photos of it in action.

[micro sailor]

I sailed her yesterday,I am wrapped with the performance I have been able to acheive.
This small boat sailed in 12-15mhp winds and a 4inch chop...amazing to watch
Yes a lot of new features,all of which I am happy to report worked well.(some may find there way back to a the larger footys)This was possibly the best first sail of any boat I have built before.
There is a good chance that this type of boat will be manufactured by a 3rd party.
2 of these would make great pool match racers.

[ROADTOAD]

Cute!!!!

How about indoor pool races in the winter for all you snow bound folks. A couple large fans blowing across the pools surface should create enough wind. :)

[hew565]

This was possibly the best first sail of any boat I have built before.
There is a good chance that this type of boat will be manufactured by a 3rd party.
2 of these would make great pool match racers.

But I want one NOW!
:)

[micro sailor]

Thanks for the comments guys.
I havn't really had much feedback on these very small models before.I bet most think I am slightly crazy for going down this path.
Nevertheless I belive that racing in ones backyard is a worthy goal and that racing sailboats inside ones house is not out of the question in the future.
If there is enough interest then I can ensure these types of models are avalible one way or another.
Be warned though..gettting such small models sorted out is not for everyone.
Take a look in the micro/indoor planes sections,those guys are leading the way.

[graham_mca]

Does this new micro yacht use micro car radio too Brett? I am amazed at your neat workmanship at this size... very nicely done.

Graham

[micro sailor]

Thanks Graham.
I started building tiny model yachts when I was a boy and have continued to build this small from time to time over the years.
A small boat such as this can be built quickly and provide a quick fix between projects.
Of course as a boy the models were not radio controled,that was just the then unobtainable dream...that now 30 years later can be realized.
I have plans drawn up for models at 5 inches(20grams) and 3 inches (9grams)
The equipment to r/c them all is avalible right now for a price.

This latest 7 inch model uses the Falcon Breeze block..that is 2 servos and the RX on one board at the spritely weight of 5 grams the lot!

the smaller models will require actuators or home made servos from pager motors.
these small models can be easily mass produced also,the cheap toy type r/c units could be used and a $20 complete pool "toy" is not out of the question.
These ever smaller yachts are very challenging to build and trim,I wouldn't recommend anyone jump right on in,rather the way in would be to start at Footy size then gradually scale the work down.also i test the models without r/c first.If I can't trim the boat to sail by itself on all points of sail then it goes no further.
installing the r/c into some of these models can often take longer than building the model itself,though the falcon brezze block is very nice to work with...but its $120,ouch

I may make some plans of a small model avalible if there is any interest.

[robertcardinaux]

Hi Brett,
I for one, would take you up on that offer for small plans, as soon as you feel able. By the way, why did you decide to bend the spars on the micro?

Robert

[MeGrimm]

I'd happily have a copy of your plans too!

[robertcardinaux]

OK the momentum is building. Brett, i do hope you are feeling the pressure . . . :D

R

[RCheroske]

So MicroSailor, Those little boats are extraordinary!! That is very cool!!

Now I'm thinking that the next step is to make a little cat or trimaran. The reason for my thinking is that water is not getting any less dense as your boat gets smaller so it would be desirable to get rid of anything hanging down into the water like rudders and keels.

Let the micro boat skitter across the surface like a water strider. I wonder if it is even possible to build a micro sailer that can sit on the surface tension of the water like a water strider.......?

[micro sailor]

Ok,,yes slight pressure guys:)
Bear with me whilst I develop further for a while.Tose that can't wait could try a 1/2 size "BobAbout" footy with a longer and wider keel.a 1/2 size footy has an overall weight of about 62grams.sutible radio would be the BlueArrow 3.5gram servos,A JMP RX and a single LiPo cell.

RCherroske,Yes I have thought of tiny multis..but have not reached the limits of monohull development yet,which I think are at about 2-3 inches long and 2grams total weight.The equipment exists to make this boat right now,but I still have some problems to solve in halving my rigging and structure weights whilst maintaining the accuracy required for the models to work.At that time inside the house sailing will have arrived:)

[Twisted Sheets]

Micro Sailor and all you others,

I have been following your progress and this month's progress inspired me to actually join the group.

Your work is inspirational and I for one would love to buy one of these little boats. I am not much of a builder, but probably could with enough help.

I have been sailing Victorias for several years now.

Congratulations on the progress and development of the boats.

The Footy's are ok, but a little pudgy. A sleeker Footy, more realistic looking boat, would fill a market niche I would think.

Your micros are amazing. I have a pool in my backyard just waiting for them.

Keep up the good work .

Twisted Sheets

[micro sailor]

Progress continues,
I try taking pics and videos from my mobile phone,but they don't come out so well.
I have modified the rig to a single sail version similar to what I used on my 4 inch model.
The boat is sailing really well in all conditions.I am having a blast sailing it.
Others are amazed at how a yacht so small can sail at all.

I really want the final model to have a sloop rig though as it looks more realistic,problem is the 2 smaller sails are much more complicated and harder to trim exactly at this size.The look I am after I guess is that of a minature Marblehead class model.

[micro sailor]

A couple of shots showing the model in its current state,It has had 4 rigs in 2 weeks,all seem to perform ok but some are easier to trim than others.

[robertcardinaux]

hey Brett!! Congratulations: 0600 AM and seeing this really WOKE ME UP! What materials and what approach were used for this micro and the other hulls (e.g. Peanut)? Are you carving, laying up, molding or what? Geez!

Robert

[micro sailor]

The 6 inch "Peanut" model was made by carving from foam,"planking" with tape then laying up a glass shell over the top.The finnished glass hull is released from the "mould".

The lighter models..ie the 4 inch and the current 7 inch models are made from solid bluecore style foam. the outside is coated in a thin epoxy/microlight slurry.
The insides are hollowed out to accomadate the radio equipment etc.

[robertcardinaux]

Brett, thanks. On the solid foam hulls, do you "sandwich" the foam to get the draft you want, and if so, what glue do you use in order to avoid "hard spots" that won't sand down as fast as the foam and keep you from getting a smooth surface (they look smooth!)??
R

[Aten W Arthog]

These look wonderful. Excellent work. Even in their current state, what with the America's Cup coming, you might be able to market thousands of them. I only wish the keels could be drastically shortened to make tabletop sailing on a half-inch of water possible. There may be a way...? When I took windsurfing lessons, my "keel" (daggerboard) and rudder were fixed, and all the turning was done by a weight/center of pressure shift of my body and the mast. This may mean a microship could be sailed with a single channel for combined sail and rudder, if the variable-weight system could be worked out. I'm imagining the mast just tipping forward and aft like the pointer of an electronic meter... meters like that are driven by a simple coil and magnet like the rudders of bitcharger planes. Make the boats twice as wide, half the draft, lay multiple keel strips along the bottom.... hm?

A keel strip that was shallow but ran the length of the hull bottom might be enough in terms of area, even though it would be less efficient. Multiple ones may be enough?

I'm picturing a hula hoop wrapped in plastic to make a "pool" on any sturdy kitchen or dining room table or a basement floor.

Can it go even shallower? What about tabletop RC sailing on a one-millimeter film of soapy water?

[micro sailor]

They are all cut from a solid peice.If I had to join them I would use Polyurethane glue (Gorrilla glue)and I would make the join down the centre line.
The epoxy slurry can help you fair out any small imperfections,take your time and you can make a very smooth/fair/accurate hull.


The concept I am working on can be scaled down to hulls around 2 inches long with draft of about 2 inches.I think that say an 8 x 4 plywood pool only a few inches deep would be adaquate in the end.Equivalent to sailing on a billard/pool table.
You really need to get the keels deep into the water to get away from surface tension/miniscus effects etc.A purely on top of water light weight sailing machine would not be able to sail to windward,though would certainly go very well downwind.

[robertcardinaux]

Brett, thanks for sharing this. I haven't worked with foam. Do you have a link that will help me identify the right kind of foam to use?
R

[micro sailor]

Sorry I don't Robert.
I have a whole heap of yellow foam similar to Blue core foam that is used for insulating houses.
A home depot type outfit may be the best source,others may be able to tell of a likely source.

[bobskinner]

This might not be the right place for this post, but my boat is a tad smaller than a footy i suppose. I am building the razor hull (my first sailboat) it printed out at about 9inches so that's what I'm building it at :) I have not posted a build thread since I did not want to have anybody waiting for weeks and weeks for the next post (busy busy), sorry, but all the info you guys have has been of enormous help! Thank you all.

Now to my question, I have a limited number of servos currently available, what kind of torque am I looking at for this size boat for my sail servo? would 2.5kg-cm/35oz-in be sufficient or should I go bigger? I'll post some pics of her when I am done.

Once again thank you all for all the very helpful info you folks share.

Bob

[robertcardinaux]

hi Bob
if it fits in the Footy measurement box*, it's a Footy, if you want it to be, provided it meets the other class requirements, which for servos means 2 channel only, using standard servos and 4AA batteries. If you don't care about joining the class, a smaller servo will save weight and still do the job at this size.
Check into this: http://tinyurl.com/y3e5tc
(class rules* on the AMYA website).

R

[micro sailor]

being 2/3rd the size total weight will have to be much less.
around about 143g if my calculations are correct.you need half that weight to be ballast so this means you will have to build the hull /rig and radio (incl batteies) for approx 73grams.
So your radio equipment is going to have to be very light indeed,sub micro servos and Lipo batteries I would expect.
Nice project,9inches is a good size for a pool sailer.let us know how you get on.

[Bob Starr]

hi Bob
if it fits in the Footy measurement box*, it's a Footy, if you want it to be, provided it meets the other class requirements, which for servos means 2 channel only, using standard servos and 4AA batteries. If you don't care about joining the class, a smaller servo will save weight and still do the job at this size.
Check into this: http://tinyurl.com/y3e5tc
(class rules* on the AMYA website).

R
Robert,
That is a misconseption that has been cleared up awhile back. You are not required to use standard servos to meet the class rules.

C. CONDITIONS FOR RACING
C.1 Control is restricted to 2 channel radio control gear.
C.2 Batteries are restricted to 4 no. AA size batteries placed within the hull.
C.3 During an event the following shall apply:
(a) ballast shall not be changed, moved or rotated relative to the hull.
(b) no more than 2 sets of rig and sail(s) shall be used.
(c) the smaller rig and sail set shall not project more than 305mm above the top of the measurement box.
You can use any size of servos, they just might not have enough torque in certain conditions
Bob

[robertcardinaux]

Bob, that's great!
Thanks
R