Evolution, stuff to improve

Salt water took its toll

 Jib sheet tube broke of the deck, it is fixed with bison, plasteline 5min epoxy, it is rock hard and great to sand! At the same time i reinforced the mast ram from beneath

 managed to tear the deck, when i was trying to put the iphone inside to measure speed and course..
..the tear is minor and will befixed when i get home

Below is a crack in spray fillar, many such cracks appeared where i haven't sanded it down yet, the cracks are due to the thickness of the layer  and is not structural, this was verified by sanding some down to bare glasfibre.

Sailing in good wind here in premantura is great fun, even with an unfinished boat :D

Getting close with Evolution

Still here in Premantura, Croatia.
The wind is ok, up to 8 or 10 knots everyday, the wave is unnoticable.
The conditions are ideal for A-rigg. Thiis are the conditios that f5g boats love.
Since these are very light boats with lots of sail-area they don't really like waves and riggs have to be change quickly.
But I desing and build my boats to suit in these prevailing conditions here on the croatian an slovene coast.
After three days of focusing on sail trimm Evolution handles like Fila only better. It has slight weather helm and points high, just like Fila. Unlike fila it's cg is far, hydrodinamicaly too far back.
Meaning that the bow likes to clear the waves, the cg position combined with a short distance between the rudder and the keel finn makes the boat happy to tack, and lively and very fun to sail.
It really feels almost skiff-like. The funnest(most fun) rc sailboat i have sailed so far!
The force from the sails seems to put the boat on the predicted waterlines as soon as there is some wind. I light airs this boat Will be probably slow, because the stern is about 7mm under when the boat is static. -as soon as you can feel the wind on your neck and the boat heels it sails beautifully.
It seems that cg far aft is a helpful tool when dealing with a boat whos' waterline is short and caries lots of sails.
to the pictures..

this is the max reasonable heel angle for this boat, above that the deck gets flooded.
That must be more than 30deg, lots of heel for such a wide-ass boat to sail normally

it points really high, with less nose down than fila!

but the wave crest is quite high, this boat definatelly won't exceed the hullspeed by much when saing upwind

the max "resonable" heel angle again, the rudder is getting some air, which offcourse is not good, but even worse the keel is already starting to show. No bubbles seem to travel down the foil..so no ventilation it seems...
the waterline is very narrow and the hull is pretty deep when sailing like this

the boat reaches speeds of up to 5km/h in such conditions with no wave, this seems to be a limit.
the rudder foil keeps the stern down, but if you look closely there is very little water unnderneath it

in a gust it just keeps going, if i don't pull the sheet in the main sail trimm goes shit, like here

too much heel, the back 15cm of the deck is getting washed.. this is a common site on most rc sailboats

when really powered up and pointing high the top of the jb depowers and interestingly the square top of the main starts fluttering so you can hear it.

bearing away...

..foil kicks in when the speed is up, and bow goes up in the next moment

 out

The sea and the salt featuring evolution

At the moment i am in Premantura, Croatia near Pula.
Evolution passed it's first hours sailing in saltwater with no problems.
Today the wind was up at 11am gusting just above 15 knots with about 20cm waves.
Perfect conditions for f5g b-rigg.
I was sailing evolution, with a b-rig borrowed from Fila, and a new slightly bigger rudder with a foil.
The boat is very fast and ready for racing in such conditions.

 

upwind is the usual; hit hullspeed, point high, work the waves..

Here are some pictures:

downwind is a blast, the boat actually starts planing(yes it doubles its hull speed which is offically considered planning)

in hectic conditions the foil keeps the stern planted, so far i haven't ever stalled the rudder or lost control downwind!

picasa is shit software for editing photos..

main sail trimm for downwind is something to improove, the spreader is in the way of the sail, and i have no clue how to solve that problem, yet

this is still happening when bearing away..
no big deal though.

this is the new rudder, it is larger than standard, the foil attached is a hq3.5_10% thickness low renolds airfoil originally for model gliders 

previous experimets showed that an angle of attack of 1-2 deg is enough to keep the stern planted, so this 100x60mm foil is tilted 1.5deg downward.

So far so fun, thw boat is showing some cracks around the mast ram, these will have to be fixed before painting.
I am happy with the boat.
I will keep collecting speed and course measurments with the mobile phone inside the boat for the next week or so and come back with another post with a more numerical approach to the evolution of F5g sailing yachts.

My my IOM triple crown

About four weeks ago i tracked down an IOM boat on a local craigs list style webpage.

The price was not written, but i recognized the boat from a couple years ago.
In fact i tried sailing this boat about 4 years ago, we had a laser regatta and IOM guys had were also there.
I remembered that an acquaintance of mine bought it for something less than 1000€. So the price could not be more than that.
I gave him a call, he told me a few details about the boat and after we discussed the price all that was left to do was 300kilometers to pick up the boat.
It came like this:

The boat was made by an experienced builder who i know nothing about, except that his name is Iztok and that he knows how to build a nice boat.
Luka, a friend and enthusiat with whom i share many areas of interest told me that more of such IOM boats were built by this guy, to race the once existing Slovenian national championship.

The condition of the boat can not be seen in the pictures above.
But the boat is new, literally.
It has been sailed three times before i bought it for less than 500€, now that is a bargain one metre!

It came with a primitive charger and a 6chanell futaba radio, which i will sell asap.
The rudder servo is graupner standard.
the winch is this:

this "regatta" whinch is no good it is way to slow, 180deg heavy duty servo should solve that problem

the remote it came with:

 and the boat is well equipped, it has a neat switch and an expensive pulley:

the only thing that had to be replaced was the bungee keeping the tension so the sheets stay in check, i added a dacron patch to protect the hull

the finn seems to be full, carbonfibre skin, glasfibre and carbon rod core, it is probably quite heavy

the rigg is simple, the sails are made of kimoto foil which is too heavy

the sails are nice tho, the shape is good, i added my tell tails and went for a sail

so far i only sailed this boat once, in ok conditions

I am super satisfied with the buy.
I got alot for my money and the resale value is gonna be good.

This boat will serve as a comparison for my designs.
Offcourse i will also take it to races and have lots of fun with it.

but first(to do list):
-buy 3 sets of sails and masts from jelacic sailing/build three riggs, A,B,C
-replace the winch/servo, because this graupner regatta servo is way to slow
-get a measurment certificate

-go to some races, i am looking at some in Austria and Croatia all in a 200km radius

More sailing pictures and thoughts about the boat follow.

Eolution's evolution

Putting evolution through different setups has been very rewarding so far

sporting a 50cm long keel, the deepest in the fleet, made of hi tensile aluminum

the cg is now 10% aft of midboat, the bow is light, the boat is light nad lively

but also destructive

Two new principles for F5g class.
-More is more

-Keep the stern planted

These two will take my design dimensions up.
Aspecially the sailarea, the mast will also move back, as the rudder foil neutralises the helm.
Keeping the CG far back gives the boat skiff-style livelyness.

Ptuj race report

On the 21. of June i gave a second go to organizing a national class regatta.
The race was a sucess, 11 competitors present, wind was good, and river flow made racing interesting but not hindered.
Me and my father took the top two spots sailing evolution and fila. Niko was third.

Full report soon

Radeče race report

On Saturday, 14th of june, the 4th round of the national championship series took place in Radeče.
The course was set on a slow flowing river Sava, the current made racing quite interesting, sadly debris in the water spoiled the fair play a bit. The wind was good, fairly constant, gusting up to 15knts.
A good day to see how evolution handles racing chaos.
At first i was sailing wih no front rudder, the keel finn is in theory big enough to provide lateral support. Yes the boat sails, but there is too much leeway, aspecially compared to the slender deep hulled boats.
After two races i added the front rudder. The boat is way better this way, leeway is reduced to a minimum, if needed it can even be eliminated completely.
The tacks are very fast, lots of speed is lost compared to the hevier, less leaning Fila. But evolution accelerates much better.
Control downwind is maintained all the time, even when the boat nosedives.
Immediatelly i started a string of 4 1st place finishes.
Evolution was fast had angle, but the hadling was shit...
I found that this boat has the mast tooo far forward, more about the reason for this mistake in another post. So the boat has leehelm, which is very anoying an usually slow.
I tried to cure this by leaning the mast bac as far back as it would go ~ 12deg, the kicker on the main was set tight and the jib was far out when sheeted in, but still the leehelm stayed.
A new rigg is needed, in order to move the aerial CE further back.
Another great benefit of the forward rudder is hadling downwind and reaching. When sailing these two directions one can steer using only the fore rudder.
This way the boat handles very directly, an looses next to no speed even at high alpha.


below are some pictures of the regatta:

this dragon force is often present at races, it has a rigg bigger than legal for rg65 class

 
 

After 8eight races the race was finished, the results are on this link:
http://forum.modelarji.com/viewtopic.php?f=13&t=88284

Update, videos surfaced.
1st race

second race above
third below

fourth below