Friday, September 27, 2013


Today the first gen of lasercut parts arrived:
the parts will be sanded around the edges, and polished

Building riggs will be much easier and faster now+ i have something to offer the guys at the races
And its nice to have something go from a Solidworks part file, to a product!
These parts are rostfrei(2mm) , ment for all riggs, aspecially C and B.
The next generation will probably be out of aluminium and somewhat refined.

Race in velenje

On saturday at 11 am we arrived a the lake, no wind.
Seascapes were sceduled to have a regatta too. But the clouds wouldnt budge.

after the training sessions 8 races were sceduled, with a 30 min pause for footys
The footys barely moved, but atleast other people could see them and gain interest, sure enough i left the yellow Karo with the builder of many hulls, and a keen race(#48) for examination and hopefully building copies of it!
 I managed to be dominant on the startline, but #93 is a boat specialized for light winds, weighing 400g lesser than Fila and ofcourse faster in the drifters.
My father was sailing #88, blue life, the boat needs a bigger rudder for beter manouvering.
He finished 6th, and was quite happy :)
I was 2nd, good, but not good enough, as i have to win the last race of the series to have a chance of taking the national championship.

#93 stands 3wins 1second
me, #87 2wins 1 second

 The last race in the season is comming in a month and a half.

Friday, September 20, 2013

Velenje regatta

Tomorrow is the 5th round of our national championships in F5g class. Me and father are going.
But this won't be just a race but also a chance to promote the footy class.
Here is a part of the dellegation, Fila my F5g boat, 2 Karos, 1 Duck, 2 Spade footys(the one far left) and the other is at my father's. Duck sits in the measurment box, and not all riggs are shown on the pic.
Other competitors have agreed to use their recievers in footys so we can have a quick 5 boat regatta on a short course.
More after the race.

Duck footy

Today it was time to finally take out the Duck, a footy designed by G. Sanderson, as far as i know only three hulls were made. There is little data available on the net, but the boat was featured in this article:
Mr. Sanderson sent me some basic measurments so i could complete the hull, which he sent me almost a year ago, after we met in Sestriere at the 2012 footy gold cup.

The rudder is made like suggested by the photos, her designer sent me, the finn is a 10% chord thicknes helicopter blade
the keel box is 1cm longer than the finn so it's position can be adjusted, the hole in the deck accomodates my 4x8cm servo module, and acts as a hatch
Two balljoints hold the rudder, and a piece of brass tubing secures it with friction
Here is the boat with the karo a rigg
The boat has it's LCB shifted far forward, which makes the waterline round at bow and slim at stern(sort of fish shaped), such volume distribution trimms the boat under heel in a very special way. The stern actualy drops, and the attack angle of the finns icreases with heel and that reduces leeway, succes of such Wl shape was proved this year with Phil Tylers SLiM design.
I didn't do any calculations on this model, so i was unsure of it's balance, but right away it became obvious that upwind balance was bang on!
But nothing is perfect, when nosedivng downwind control was lost at times, because of the rudder which is to short.
Eventually the rigg was changed to the new a rigg with 1500cm2
The CE is recessed some 10mm compared to the original rigg, but that didn't seem to affect the upwind balance.
Clip 1


Overall i am very pleased with the boat, it seems to be fast in all directions. The wegiht is 360g + rigg(40gmax), which is quite light. Ballast is 200grams.
It will be used for speed and angle comaprison along side with my KAROs for future footy projects.
If interest for footys rises here in Slowenia it will be at the front end of the footy fleet for sure!

Thanks to Mr. Gary Sanderson for giving me the chance to finish one of his hulls!

Monday, September 16, 2013

Fila in home waters, a rigg mast back in one piece

Fila's mast was repaired, now full of carbon rowings, the upper part of the mast is stiffer, which is actually good, because the 11cm long mast crane tends to bend it in the upper third alot more than lower.
Anyway the luff curve was recut, and the A-rigg is ready for the race on saturday.
out of the jig, A.k.a. 10x10mm alu U profile
4g added

Also managed to get a few good b-rigg sailing hours during the past few days
tried flaps on fila:
taken from Karo, but set at a smaller angle to wl
only 5mm above the static wl, they drag when sailing up-wind, so the boat hops over the waves and doesn't cut through them like normal, will have to sail against other boats to se if it affects up-wind speed, but it definetly helps alot when running! clips follow
F5g Evolution, the project set aside in 2013, i am looking forward to finishing it this autum:
the boat has a fixed keel, and two rudders one in front and one in the back, electronics are placed in the bow, for balanced sailing in the prevailing flat waters where f5g sailboats are usually sailed, and in order to experiment with different weight arrangements in the boat.
forvard sheet outlet and mast ram

more in another post.

Sunday, September 8, 2013

Flaps on KARO footy and over-powering the a rigg

We had a few days of good wind here in Maribor, SLO.
The wind on the pond in the city park was gusting up to some 10-12knots and shifty.
the trimm, the pivot point of the jib was set 4cm forward.

a crappy clip:
It seems like the vertical down force created by the sails is quite big in relation to the available volume in the hull. The boat gets pushed down upwind.
Obviously a solution for the next evolution of the karo is more volume, but i have also tried flaps below:
The flaps are at an angle which would be considered stupid with normal boats but at footy speed, or at such low renolds numbers it seems to be the most effective, and by eye it doesnt hurt the speed at all!
The flaps help to keep the bow up when over-powered upwind and reduce submarining downwind.
I noticed that leeway was increased with flaps. That was because the flow separated of the flaps and the hull, and then reatached at the end of the first half of the hull.
The midle third of the hull is the part where the chine provides the most "grip" upwind, so i cut the last 3 cms of the flaps, so the flow would separate earlier(from the flaps), and reattach on the hull after the first third so the whole middle third is immersed.
the cut flaps

Below is the clip of sailing with flaps, if the flaps do any good will be confirmed when i get another chance to put both KAROs in the water.

Tuesday, September 3, 2013

No regatta, footy update, broken mast on Fila...

Sadly i could not take part in the modelympics regatta on friday because of family matters..
The next chance for a win is on the 21st of september in Velenje, a small town, with a lake, where the next round of the national cup will be held.

The new main sail on Fila seems to function well, or atleast it did, until today.
The mast was broken, when i got tangeled in a bush who's branches extended above the water..
it snapped where the upper shroud attaches to it, a clear weak point.
After that i went home, disasembeled the rigg, and weighed the mast:
It will be repaired, carbon rowings will be itroduced, filling the inside of the mast, hopefully adding only some 5g of weight.

The footy..
..momentarily i have a mess in my head, not sure which way to go, but have plenty of ideas.
here is KARO beating with the b rigg sporting 1500sq cm, and a bad trim on the new main sail, with the help of wich the CE was recessed abit, for beter helm balance.

Downwind, the classic rigg looks very promising, judging from the waves the boat reaches hullspeed, and the sails wont sink it more than pictured here(the unarigg would sink it so much that water would flow over the deck, when heavily overpovered)

The classic rigg functions well when the wind is perfect for the specific rigg or is overpowered.
Problems appear when there is no or less than 15 degrees of heel. The boat starts making way too much leeway, it also looses angle, consequently one must tack through about 100degress wich is a disaster.
Obviously the hull is the thing that gives "grip" for upwind sailing.
The next step is to try and make the about 350g bulb replacable with a 250g bulb.
I will see how the light boat goes and go from there.