Monday, November 24, 2014

November update

December is going to be busy!
The way i like it, i hope school won't stand in the way too much.
3 projects are active all to be finished till the end of January.

My father and I decided to take part in the 2015 footy gold cup. More info will be soon avilvable on a dedicated site. For now Thomas(the german footy registrar) is keeping some of us updated on: http://www.footy-sailing.com/forum/showthread.php?tid=308

Footy first:

This is Booyah, my 2015 footy design. It already is the first(known/proove me it isn't) 3D printed footy. Photos follow.
The design is placed into the box longitudinally nose down.
giving it a max lwl of 33cm.
The all up weight should be 450g
But the 3d printed prototype won't be as light. After testing and improovement the boats will be made of composite, to save weight.
The hull has a high prismatic coeff. and plenty of reserve volume. It will carry a classic rigg. The A_rigg will exceed 2000sqcm.

Then come the rg65s,
Some sailors here in Slovenia decided to start building them. 2goths, one own design and two other are looking for boats.(that makes 8, counting the dragonforce seen on regatas, me and father)
It looks like rg65 is going to be the new class here in slovenia.
So i picked up my left behind projects..
the jif65:

which only needs a bulb, and a paint job(to cover porosion)



and the angeldust rg..

..it is a 9/2012 design, designed to be nothing special, following the common rules of thumb know in naval architecture. Only the rigg will be somewhat special.
It is intended to be an allround boat, and a rigg testing platform.
I already made a plug and a hull for it, but it is twisted, so i wont use it. The past two days were spent drawing the sucker in solidworks, refining the rigg and bow sections. Today i have the files ready to start 3d printing the new plug.
It will be hopefully printed by sunday, so i can glue the parts and get the plug ready for moulding.


There is also the new fila which has to be finished till late may. To startthe national championship season.


The battle plan is to get the angeldustplug printed asap.
To finish the footy in the next 14days and trial it against Karo.  -then analyse & improove
The jif should be done till new year.
Angeldust should be done till end of january, to test agaist jif and hopefully other rgs.

Monday, October 6, 2014

Koeze race report

On the 4th of october the last race of the national championship took place in  koseze pond.
The report will be fullfiled soon.

The races were streamed live at:
http://new.livestream.com/zivo/MODELARJI-NA-KOSESKEM-BAJERJU
clips of all but one race can be found on that link

Velenje race report

On the 27th of septembre i was supposed to be with the italian footy gang sailing footys. But school would not let me take the 700km trip to north-western italy.
So i attended the 5th race of our national championship in the F5g/750mm class.
Velenje is alway a nice race, sailed on an artifical lake which is a consequence of heavy mining activity in the area and the site of the coruptive project teŇ°6(part of a thermo electricity plant).
The water is clear blue, warm and wind is usually pretty good.
12 competitors showed up.
The line up was as competitive as it gets in the 750mm class.
8 races were sailed. First there was no wind then the wind came. then it was gone again and later it came back again. Not exactly the "good" wind i was expecting.
but the race was lots of fun and i am particulary proud of the first race. Because there was almost no wind and nr.93 was just behind me, but i managed to fight him off and took 1st.
The rest of the race was mellow. Start hard, stay right. Keep up the speed.
When the wind came evolutions speed was untouched. but in the luls either 93 or 331 and 334 were always close behind.
My father short curcuited(or however it is spelled) his electronics. And with no backup servos fila was out of the race. He had to do with am reserve boat from niko. But it was a completely different boat that he is used to and he was just not as fast with it.

My hopes for the race were high. I knew if i get the win i would have enough points to claim the national title for the second year in a row.
Luckily i did it.

Photos and videos will be posted soon.


In week before the race an older sailor passed away, his name was Ivan. He was the grandfather of an acquaintance of mine. He loved building model boats, and enjoyed national championship races.
He was not always on top of the rankings but he did it with a smile!
Until a heart complication took him away, may he rest in peace.
Velenje race was the race he was always eiger to sail. This year he built a new boat, which was supposed to sail for the first time that weekend.

Maybe that boat will sail in velenje the next year, to honor his memory. Also i will suggest that we name the race as his memorial.


Wednesday, September 10, 2014

more 3D prints

below are some of the 3d prints i did for people who contacted me.
Most are my designs(from solidworks), some are from thingiverse.com.

My development, a gopro clicker, reinforced design, tolerances apropriate for 3d printing
the difference

offcourse it is interchangable with the original


servoarm and rudder shaft support for fila#89
130mm extension for gopros, printed with 100% infill

layer thickness here is 0.2mm for fast printing


gopro frame from thingiverse on a custom mount to slide into the universal dslr flash mount

0.2mm layer again

fittment tested on this olympus, canon 5d and nikon d90 fits perfectly!


this is a samsung galaxy mount combined with the dslr flash adaptor

no clue why the client wanted to attach the gopro and the galaxy to the dslr..

drift-trike wheel, but the nozzle got clogged

gps case for a Naza controled hexacopter
mk1 parts for the helmet swing mount
 I decided stop using 0.2mm layer thickness as the surface finish is much worse compared to 0.15 or 0.1mm layer height.
So from now on i only use those two layer heights for components that don't require a very good surface finish.
0.1mm layer bmw e36 jacking "mushrooms" they hold the cars 1250kg no problem
foglight delete plate for the bmw


vw bus, needs cleaning up

printed this and stuck it to the cealing with hot glue, thingiverse search: cute octo



Monday, September 1, 2014

Fila #89

At the rogla race Niko a fellow sailor gave me a fila hull, with a built in finn box, finn and rudder. Thanks alot again!
So the goal was to have the boat sailing by now but fiddeling around my car and school made me postpone this project.
This boat will be an improvement to fila #87, it won't be perfect but it will be good.
It will also showcase 3d printed parts.
The boat will be primarily a one keel fin one rudder boat, but a fore rudder shaft will be also fitted.

as i got it, the keelbox was prfectly aligned the rudder post was of centreline for 2mm


rc stuff mock-up, a laid down sheet servo is a first for me

standard b-rigg is used for mock-up of eyelets for sheets and shrouds
3d printed mast box, the mast rake i adjustable 3-10 deg of backwards rake

this is a new material i use, its bison plasteline epoxy, its a 5minute epoxy, gets stiff as a rock and is very nice to sand

shroud from the inside(3x2cm patch is enough

backstay, the hook is made out of 2mm alu bicycle spoke

keel finn, the target weight is 1600g, but i wont go below 700g of ballast! lots of wolume to play with the original fila weighs 1850g sail-ready

all glued in, the finn box was in the way, so i cut it, still enough space for the keel to fit inside..
..the woodden supports area waiting to be cut abit more..

everything is stainless steel(1mm, tig welding rod) or aluminum
First test will be carried out with evolution rigg against fila#87, evolution 50cm deep keel can be used on this boat.
Looking to get the sheeting sistem and new rudder post&rudder glued and runnig by the end of the week.
That is it for now.

Thursday, August 28, 2014

Model olimpics

Every year model olimpics are organized on Koseze pond in Ljubljana.
Usually three F5g races are organized, marathon/navigation on Monday, match race od wednesday and a regular regatta on Friday, this year is no exception.
Sadly i missed mondays navigation because of the upcoming exams.

Wednesday

Hoewer my father joined me yesterday(wednesday) to do some match racing.
We arived at the pond and the Jury decided to make it a normal race, but that only one lap around the course should be sailed(instead of two), to save time.
No results were discarded at the end(i have no clue why?). Meaning that every "bad" result counted and consistency was crucial.
The wind was typical koseze shit, the windward bouy was set towards the trees and there was no wind. the rest of the course was sailable, but luls lasting about 5min were present from time to time completely stopping the happening on the course.
The event was fun nevertheless.
The starts were pretty important because the firs buoy was only about 10m from the starting line, and a reach followed. The left side of the starting line was heavily favourised.
I messed-up 3 starts, but all of the rest is started as close to the left bouy as possible and always came first to the windward bouy.
My father was charging too, Fila seems to suit his sailing style. He took a strong second place, leaving the third 8 points behing.
I took first easily. Evolution is the boat to beat at the moment.
Most of the succes in these low-wind conditions comes down to it's stiff, perhaps to stiff, yet shallow sails. Which take form easily, and pop to the other side with ease. Meaning that each gust is used as propulsion and not as a sail turning/poping tool!

Friday 

The last race of august is over. Conditions were Koseze specific, zero wind, and i mean zero.
18 competitors showed up. The racing was not exactly exciting as the boats barely moved.
The conditions were made worse by rc powerboats driving near the race course and the organisers did not tell them to stop driving because they're making waves.
I was sailing evolution and was struggling with bad luck and wrong decisions about where the vacum is going to suck the boats. So i was following my father in 3rd or 4th place in most races. He was doing much better with a string of second places.
Leading was #93 a low wind specific boat.
I was a bit frustrated, because there was nothing i could do to better my performance. I started sharp on the right side but couldn't match the speed(slowness) of boats with less wetted area like fathers fila, #49 and #93.
Then there was a 20min pause, me, father and skipper of #93 helped peter a sailor in the wheelchair to get to his car because he was leaving due to heat and zero wind, i came ba about 10min after the pause was declared to find that there was only about a minute left to the next start.
This was a bad bad move by the organizers. One does not shorten the pause without informing all the competitors.
I decided not to sail in that race but i did put together fila trew it into the water and when my father arrived he sailed the race and dispite starting a few minutes late he cam into the top 5.
Me and #93 did not start that race.
Tbh i was dissapointed, the organizers did shit.
The final results are not out yet but #93 was first with all bullets but that one race. Niko #49 was second because he won that race i was left out of. I got third and my father got 4th. now how the fuck did he get forth? he was ahead of me in all race but one. in that race he caught a dead end line that was floating around a bouy(organizers shame on you again), and finished second to last or something like that.
I am pretty sure that they messed up something, we will see when the results come.

Rant

Yes i know that rc sailing or to be exact the F5g class here in slovenia is not such a serious thing like IOM in croatia or Rg65 in south america but with negligence like seen on friday rc sailing here won't ever become a serious hobby. 
Not saying that it(sailing) should be to all, but for some of us it's not only joy but much more.

That is why Slovenia is a small country with a little bit of everything, because certain people tend to work on their own and strive to achieve their goals more than the others. Such people standout from the crowd, it is becouse of them that Slovenia is succesful in many sports from the outside. But these successful people are alone, Slovenia fails to deliver offspring in sports(and not just sports) because of a careless attitude seen all to often. 

(added:
Real succes will be delivering quality offspring for generations not just picking the best one from a generation and feeding him to the world saying "look we very good at this".)

After the sailboat race an exhibition of all models was sceduled.
picasa pictures won't load right now so they are coming soon..



Saturday, August 9, 2014

Bonus photos of evolution














Evolution clips

One day a small storm came in at Premantura, the wind was Yugo, know as a warm, humid wind creating good waves out in the open.
When the clips were shot the average wind was about 18knots, you can see the wave size for yourself.
The handling downwind was excellent, no drama. The only reason for not flying the a rigg is the inability or the poor ability(even with b rigg) to tack, when sailing upwind.
This is due to the low mass of the boat and the waves.
I don't know if anyone ever sailed an f5g boat in such winds. As the races are usually held on clam ponds.
Whatever, if such conditions arrive at a race i will be out sailing, having fun with my model yacht.

Friday, July 25, 2014

more & more &more = same as before


I spent one of the last "holiday" days sailing evolution, with a rigg, in conditions above the riggs range(10-15 knots). Hiding behind a dock, where the wave was relatively small.
The reason for sailing in in a windy but waveless spot was to observe,by eye, the behaviour of the boat under lots/excessive power.
By eye it seemed that upwind the boat would sail just as fast as it would with a well trimmed b rigg, perhaps there was more drift. But i think that the same boat with both riggs would perform identically.
Downwind the boat sails fast, but even at top speed the sails stayed tense, full. Delivering power that was lost because the boat would not accelerate more.

I was pushing the a rigg to the limit.
What is this "limit"?
This is a wavemaking drag barrier.
According to mr. Edmond Bruce, author of "design for fast sailing" by AYRS, the wavemaking resistance barrier, displacement boats face when sailing close to hullspeed, is less noticable when Lenght/beam ratio of a slender hull reaches 8. This "barrier", or a steep hill in the wavemaking resistance ploted against speed graph almost disappears when a hull reaches l/b=11.

I will use this post to go back to basics and come up with two ideas for future F5g boats.
Both ideas have been realised in the "big boat" world but have not been pushed to such extremes due to structural and seaworthiness limitations.

The goal is to make a fast boat.


In order to make a fast boat we need a force to move the boat.
Here the rule is simple, the more power(sailarea) a boat has, the faster it will go.

Some will argue that if the sails are more efficient a boat with less sail will sail just as fast as boat with more less efficient sailarea. Wing theory proves that, but in the real world a boat with more sail will be the first to start reacting to wind, if there is little wind. A boat with more sailarea has more tourque powering(moving is perhaps a better term) it through waves. The boat with more sail can take the wind from the boat with less sail etc.
The above are race proven facts that are true most of the time on a race course. But there are some drawbacks of carrying lots of sails.
Since we are talking about model boats that measure less than one metre in lenght, longitudinal stability is an issue. Our models tend to sink the bow, submarine so to say. Footys and IOM boat suffer from this greatly. In f5g i have succesfuly adressed this issue with a foil attached to the rudder, the foil is inverted, so it is pulling the stern into the water.
Yes this foil increases wetted surface and induced drag, but the area of sail i can carry with this rudder is much much bigger. Example: Fila has a5500cm2 a rigg, without the foil it can carry its rigg to about 8-9knots of wind(average wind) with the foil i sailed downwind succesfully in winds of 14-15konts! Evolution can sail with more than 6000cm2 up to 15knots of wind!(it has more bow-volume and a longer keel than fila)
The second issue is transverse stability. With no moving ballasts the most effective combination is a wide hull and a long keel. The combination of both gives the boat a satisfactory counter-heeling moment.
Big sailarea requires a wide hull and/or a hevy bulb. We can fine tune this combination to give good results with the chosen sailarea.
Until now i have never asked myself how wide can a monohull be? The idea of a 750mm 400mm wide F5g scow type yacht is interesting, but hullweight will probably be the downfall of this project.
The problem with wide hulls is that they all make a deep/high wave, causing a lot of distortion over a large area. Despite the consequental high allup weight such a boat could carry lots of sails and putt other f5g boats in shade. Planning potential downwind would be good, but upwind under heel it would not sail past hull speed leaving it just in front of the rest of the fleet.

Without moving ballast i can't see another way around this dragbarrier problem caused by normal displacement hulls of our model boats.

With an aerial canting keel/ballast arm and a narrow hull with a l/b ratio of 11, the boat could reach it's speed potential. The arm extending to windward would keep it right side up sailing upwind.
A rudder foil would keep it from digging in when running. Transverse stability downwind is a challenge. Sailing downwind the arm would be recracted to the middle of the boat so that the CG of the boat be about 10% behind the LCB, this gives good rudder response and keeps the bow from dragging too much. But the ballast would be placed relatively high, on the deck.
A gyro stabilisation for downwind sailing would be needed. Or capsizes would be inevitable unless some lead would be put into the keelfinn, which has to be present anyway(not really, a fore rudder could replace it, but for regata use a fore rudder is one channel to much for my concentration, and it takes away the good feel of a well balanced boat. Just like 4wheel drive takes away the livelyness of a 2wd car)
If only possible, putting led into the keel and having movable ballast at once should be avoided.
Because if you go through all the trouble of making a movable ballast sistem work, then you want all the ballast you have to be active, for maximum efficiency. The lead in the keel would be dead ballast just sitting there to save the boat from capsizing in extreme conditions.
Dispite the above practicallity along with reliability has to have the upper hand and a boat has to be desingned so that it will complete sailing the course when sailing as hard as required with no technical issues or capsize recoveries.

This was a thought about a fast monohull, to sail in a displacement or semidisplacement mode at planning speeds. For the first time i realized that it is almost a waste of time to work on "classic" type keelboats in an open class like F5g where nearly everything is allowed. IF we take a look at iom or marblehead where the rules are much more defined and refined, well that is another story.