Opalek FOOTY Racing means "Hey Sails!"
Exactly twelve years have passed since the history of the FOOTY class in Poland began with the publication of the article "Opalek - our elf among regatta radio yachts" in the magazine "V Masterskaya". During this time, the class has developed a lot, and Opalki also did not stand still. Today we will look at this design, improved by Rafal Kowalczyk (the reigning champion of Poland), who has been the owner of the best single-leg RC sailboat in our country for several years.
One-foot radio-controlled sailboats (about 30 cm long) began to participate in regattas as recently as 2007. Today they are developing all over the world! Simple rules, low construction costs and convenient dimensions make it easy for almost everyone to learn the basics of sailing, enjoy the wind and water and have a great regatta experience - even in the backyard pool!
Enthusiasts of this friendly class are eager to help newcomers to their constructive hobby, and can be found in over thirty countries and many places on the Internet. For those who are interested, I especially recommend the homepage of the International Footy Class Association (IFCA) www.footy.rcsailing.net and the Polish site of this class.
Opalek regatta – championship school
Since the aforementioned June 2009 young technician article, a total of about three hundred models have been created based on our wonderful project. It was from Opalek that model shipbuilders studied not only in Poland, but also in the Czech Republic, Germany, England, the Netherlands, the USA, Canada, Spain, Hungary, Italy, Russia and even New Zealand. There were also many modifications - both official (the nineteenth versions (1.9.9) are being built now), and interesting, though single development versions in many countries, for which the basic project served as the starting point.
1. With its classic wooden construction, Opalek is an interesting topic for modeling and shipbuilding studios - and not just for boys!
2. Our colleagues from the Czech Republic (where the name Opálek is even synonymous with the FOOTY class!) have built many beautiful models based on young technology projects. It was developed, among other things, by introducing laminated hulls (Opálek-Chmelka type) and rigid cab covers.
3. Opal has even traveled across the southern hemisphere - one of two beautiful New Zealand Opals from user Antipodes can be seen on the forum www.rcgrups.com. Among the interesting solutions are ballast screw mounting and laminated glass, plywood fins.
Since 2013, our waters have been dominated by the unique Opalek (registration POL 15), built by Rafał Kowalczyk from Wrocław, designed to win regattas. Unlike conventional models of this series, it is primarily lighter, has a different rudder blade and for several seasons also many individual sails for different weather conditions.
4. Our nephews from Hungary used interesting peepholes from baby food lids (photo: Zsolt Surman).
5. Colleagues from the Netherlands, like the Italians, experimented with different types of rigging.
6. Ola (one of our prettiest skipper boots) always starts with the beautiful Opalki - most recently with multi-bristle, stitched sails and reshaped hulls.
However, the long and conscientious experience accumulated by the multiple Polish champion in its class can also be used by users of previous versions of the first Polish sailing boat FOOTY, since many of the solutions used here can also be transferred to older models.
7. Opalek Championship by Rafał Kowalczyk found this year's June FOOTY calendar page containing examples of the best models in this class in the world.
8. Unlike most Opalek models, which are built based on standard drawings and material kits, the Opalek POL 15 racing regatta has a variety of sail kits for different situations, making it unbeatable in all weather conditions.
9. This type of drilling rig is called McRig. We saw the technology of installing two-layer sails cut out by a pyrograph from the lightest foil on English ICE models. So, let's look at the visible details of the front of the sail and the attachment of carbon tubes to the steel "zeta" ...
McRig means more power
Not found on larger boats, this single-sail McRig rig was popularized in our smallest racing class. It is used by the growing group of FOOTY bulls and has its own (aerodynamic!) justification. A single sail catches the wind better, which in most cases gives an advantage over competitors using double sails with a similar area.
10. ... and then its back with a counterweight (this ballast is often made of tinol solder) ...
11. ... and the top of the mast with a davit pulling the upper corner of the sail.
The masts used in the project described today are mounted in existing sockets, and the difference in diameter (> 2-6 mm) is reduced by sliding bushes (in this case Teflon).
12. The advantage of this apparatus, in addition to sails, is also a light hull. The frame is made from lightweight balsa instead of plywood, and the skin is almost three times thinner (0,15mm PVC instead of the typical 0,40mm PVC). Together with a slightly lighter ballast (180g instead of 200g) this gives a min. 100 g advantage at the start compared to the standard model of this type. The Opalek POL 15 retains the standard sheet servo, while the direction servo, receiver and power supply (Li-Po 3,7 V with converter
up to 5 V). The cabin is pasted over with a colorless self-adhesive film.
For the manufacture of this type of sail we recommend: elastic steel rod 2 mm for the connecting part of the mast, carbon tubes 3/2 mm, steel rod 1 mm for the top davit, thin polyethylene film (the thinnest bags), additional glue. reinforcement tape, rope and epoxy.
13. In addition to the shape of the sails, a visible modification is the rudder feather. Positioned aft on an additional crate, it has a 15mm pivot behind the transom. This gives more torque at the steering wheel compared to the regular Opalek.
14. The proportions of the body are better seen on the centimeter grid.
15. Spindle ballast (180 g) is typical for top designs. However, the owner wants to make it thinner, as does the cross-section of the ballast stabilizer.
A rod with a diameter of 2 mm is inserted 50 mm deep into the front carbon tube and glued to the boom. This connection is additionally strengthened by a coil of thread. Teflon tubes are glued to the part of the mast that fits into the nest in the deck.
16. Nine years ago, I wrote that models of this class can be carried on the water in the notorious shopping bag ... Yes, you can. But cool models for the regatta are still carried
in the right boxes!
17. Preparing a model for takeoff, changing rigging or making minor adjustments between runs is not a problem if you have practiced this in many training sessions...
18. ... and then others are chasing us!
It is recommended to make at least three sail sizes for different wind conditions (the best competitors even have twice as much). The correct choice of sail geometry is often a decisive element of success. Certain aero-hydro adjustments are possible thanks to the adjustable position of the ballast stabilizer.
19. See you at the next International Championship of Poland FOOTY 2018 - June 16 and 17 in Wroclaw!
New rudder blade
The aft rudder is more efficient than the rudder under the hull due to the longer operating arm (the effect is similar to sliding back in a horizontal turn). Assembling the rudder behind the stern is not difficult - in the standard model, it is enough to stick an additional bar on the transom and install the keel on it on modeling loops (or made from a can) according to the working drawing.
The hole for the pusher will need to be cut in the transom (stern frame), but the direction servo will not even need to be reassembled. As in the previous version, this fin should rotate 45° in both directions.
The actuator mechanism is shown in more detail in the photographs and drawings illustrating this article. Detailed plans for the construction of this model (extended version of the drawings in PDF format and 1:1 scale) are available on the website of our monthly magazine - www. mlodytechnik.pl – and beyond
See you by the water!
