Dragon Tales 2…

The final prototype of the Dragon is being built and this is being documented to form the photo building sequence for the new kit ‘photo. CD’ in the instruction set.

As mentioned in the previous post about this boat the deck will feature a dinghy style spray rail to deflect water from the mast tube. This gives Dragon quite a distinct appearance and for me more of a feeling of the real thing. The rail is tabbed into the deck for easy location. The large hatch gives quick and easy access to the radio control equipment. Construction of the hatch is based on concentric laser cut ‘rings’ of plywood to ensure a good fit. Subsequent varnishing controls just how tight the hatch fits. On the two test boats for this method no fastennings were required, the hatch simply snaps on and has proven watertight even in heavy winds.

Construction will follow our usual clean and simple approach. The forward cavity contains the two part plywood mast tube foot which locates the carbon mast tube and is sealed at the bottom with epoxy. The servo tray/keel support is in the main radio bay. There is lots of excess bouyancy provided by the foam core construction so like the Kittiwake K2, Dragon will be unsinkable 🙂

Graham

Read Full Post »

Sheboygan Footy Fest ’09

Sheboygan Footy Fest 2009
May 17th. Wood Lake, Kohler, WI.

Our third annual Footy Fest is in the book and a good and enjoyable event it was. The weather was good with wall to wall sunshine and around the mid 50’s F with a light to moderate NW wind. The forecast was for W swinging to SW but that didn’t happen unfortunately because it would have given us a less flukey wind.

I was there bright and early about 8am to set up and we had our first arrivals after 8.30. Measuring and registration was an easy affair with no controversy to deal with, we don’t do controversy here anyway. I must thank Frank Thorley for the loan of his excellent perspex measuring box, it is so nice to see what is going on in there. We had a good mix of boats and ideas to look at this year with Frank’s new assymetric sterned boat ‘GoldFoot’ and the ‘JimBobs’ from the Tanglewood (FL) guys. It was nice to see a bunch of Kittiwakes come up with their owners from Chicago from the Fleet 4 Commanders club. Three very nicely built boats named ‘Huey’, ‘Louie’ and ‘Dewey’, made me smile. We were running a little late having had some technical difficulties with the bouy launching system so after a friendly skippers meeting we got underway.

The first race went to Graham McAllister with Frank Thorley second and Toby Vetting third. I was sailing my new ‘Dragon’ design with Laser dinghy inspired una rig for the first time competitively so this was an encouraging start. Then ‘Fast’ Frank (GoldFoot) got into gear and took the next 4 races with second and third being shared by Toby Vetting (Kittiwake), myself (Dragon) and John Gallenburger (JimBob). We took some longer breaks between the first couple of races so that we could take a look at the boats which had struggled in the first race and see if the experienced guys could breathe a little more speed into them. This is part of what this Footy Fest is meant to be so it was good to see that the slower boats did improve and were later finishing just a leg or so behind.

After a good lunch break at Quizno’s Subs just along the walkway we were back bang on schedule with a restart at 12.45pm. I took the first race again with ‘Dragon’ with Frank second and John third. Toby Vetting was fourth, Larry Tregear fifth, Larry Schleis sixth, Dick Chvojka seventh and Don Powell eighth. Then ‘Fast’ Frank did it again winning four in a row with Graham, John, Toby and Larry S. sharing second and third. The last race of the day was a very slow affair but fascinating non the less. Graham won this final race with John second and Frank third. During the last two races the wind had dropped very low and some floating weed which had been held against the bank by the wind started to encroach on the course. I came ashore and pulled weed and relaunched in those races as did others so it was becoming very tense as weed avoidance became a part of the tactic. As a result of the weed we called the eleventh race as the last, just one short of our target of twelve races.

So the day was about over and a few guys had already started on their way home so the group shot is missing a few. Jan and I conducted the prize giving in the foyer of our lovely venue at Woodlake. Jan McAllister made the three trophies this year as stained glass plaques which we hope the winners will enjoy owning. The final results were 1st Frank Thorley, 2nd Graham McAllister and 3rd John Gallenburger. The full race-by-race results should be posted somewhere closeby. We hope that everyone who came along felt that they were a winner in some degree, whether they picked up a few tips, made new friends or just had a good day out. It was particularly good to see a young man among the fleet at his first Footy regatta, Adam Zimmermann from the Chicago area. Well done Adam on your 8th place and we hope to see you here again, all it takes is practice and you will be beating us older guys as you have youth and good eyesight on your side!

I would like to thank again Paula Williams of ‘The Shops at Woodlake’ without whose help and encouragement we would not be able to have the use of this lovely venue. Mark Klarkowski who was dragged away screaming by work but provided our bouy set and tug boat launching system. Jan Mcallister for making the trophies and standing all day watching the starts and scoring the finishes. ScaleSailing for sponsoring the trophies and event which keeps this as a ‘free entry’ regatta. Don Reimer who rose literally from his sick bed to help us set up in the morning. Don took 4th place the last two years so would have been a tough guy to beat with his new boat had he been able. Frank Thorley for his Footy Box and encouraging other of his Tanglewood Club members to come along too. And last but not least everyone who came along and took part, first or last, a regatta needs you all.

Full race-by-race results can be seen here

We hope to see you all again next year.

Graham McAllister
Sheboygan Area MYC

 

 

 

 

Read Full Post »

Dragon tales…

Lurking below the OPUS rig which has been getting all of the attention lately is my new hull design, the Dragon. Construction is a hybrid form of my usual system, EPS foam core, balsa wood sides, stem and transom with a high density foam bottom. The bottom is 5mm thick and this allows the chine to be easily sanded to give a nicely radiused ‘soft’ chine. The deck will be 1/32″ laser cut birch ply and internal structure to our usual pattern, which means simple and as little as possible.

 

The Dragon shape is changing a little from the prototype seen above, the stem or bow will be 1/4″ deeper and the transom 1/8″ shallower. This gives a little more reserve bouyancy at the bow and increases the deck rake a little, the transom angle is being increased too. The trailing bulb is an important feature of Dragon which allows the weight to move aft without compromising the distance between the fin and rudder, and therefore rudder efficiency. As the kit version is being built I will be adding a dinghy style spray rail and a lift off wooden hatch as has proved so effective on the recent Pond Sprites.

Production version of the Dragon foam core. 

The Dragon is a long hulled (fits diagonally in the measurement box) ‘new rules’ boat. She is designed to use a 3x AAA cell battery box for race performance but is definitely capable of carrying a 4x AA battery pack in a standard square battery holder. Being designed for and alongside the new OPUS una rig that is how the kit will be set up.

I am really excited about this project and will be moving ahead with it at full pace. As a result I am going to move forward with this boat ahead of the Pond Sprite project. I also intend to trial the Pond Sprite with the OPUS rig because I know that some people prefer a wider, 12″ long plywood boat and if the combination works then Pond Sprite will be a nice beamy alternative to Dragon. More news as it happens.

Graham

Read Full Post »

introducing Dragon and the OPUS rig

Over the winter I have been developing a different style of una rig and a new footy to test it on. Early talk about flexible rigs and their benefits for use on footys centred around the flexible mast but apparent complexities in their design meant there was little development in that direction. Later the  ‘McRig’ came on the scene and it’s simplicity was infectious and it has become rightly popular. Rather than the mast bending it used a torsion bar for the mast pivot allowing the whole rig to flex from it’s base. I wanted to go back to those earlier discussions and see if I could make a bendy mast rig work.

In developing OPUS I was inspired by the una rig on the Laser dinghy. The curved mast on the Laser is shaped by the sail pocket. I decided to create the mast curve with a backstay instead which allows the mast to be shaped independant of the sail thus allowing some sail camber control. A pure Laser rig would have the mast set too far forward for a short hull like the footy so I have adopted an offset pivot on the main boom so the rig now became a una swing rig. I have been careful to allow no flex at the base and boom mounting so all of the flex and gust reaction is handled by the flexible carbon mast and sail itself.

The OPUS rig was tested briefly in the light Fall airs here before the winter freeze set in. Over the winter the idea was developed further and hand held tests in varying winds were photographed and studied to see how the rig was behaving. Clearly the rig worked nicely as a swing una rig which would make it a nice rig to use were it simply a stiff unit. What I was looking for was how would it behave in gusts as this is becoming a key element in racing footy design.

steady breeze                        stronger                              gust reaction

Well the results looked good, in a gust when the rig is close hauled or in a reaching position the mast bends away to leeward as might be expected but it also curves back more under the action of the sail and induces more twist in the sail. We know that bending away and dumping some wind in a gust is good but increasing twist is possibly even better. The movement adds upper drive due to the twist while dumping air and also keeps the lower area of the sail as set and driving the boat forward.

‘Laser’ style swing rig in action on the Dragon prototype.

The ScaleSailing Dragon/OPUS combo saw water again on the Friday of the NCR in Orlando, FL. I took the opportunity to sail the boat and with a good but variable wind blowing was able to see how the newest version of the rig behaved on water compared to land in a variety of wind strengths. It looked good on the water, I particularly like the elegant shape of the curved mast which was different from everything else on the water that day. The sail approximates to an elliptical shape which is typically considered to be an efficient planform. Tacking was quick and easy with the sail filling quickly and the boat accelerating away well. I think this initial sail size I have chosen handled the stronger wind well and should make a good ‘working’ rig to cover a range of conditions. Being used to sailing two sailed sloop rigs I did love how easy it was to turn on to the run downwind and not have to hope the jib popped out opposite to the main. Yet there was no odd behaviour as is sometimes reported for the classic two sail swing rig set up. I am prepared at this stage to say that this OPUS rig works and works well. Clearly there will be things to learn in tuning it, controls available are mast shape via the backstay, sail foot shape and initial twist shape via sliding rings on the boom.  

As an aside, construction of the prototypes proved difficult to get the required accuracy so I had a friend make a special tool which now allows me to make the boom/pivot/mast stub assembly quickly and with the required accuracy. When the ScaleSailing OPUS rig comes into production the boom assembly will be supplied ready made along with a prefabricated mast/masthead and sail ready to simply plug together and play.

All content of this blog including text, photographs and the model designs are the sole property of Graham McAllister Designs.
Copyright 2009 by Graham McAllister Designs.

Read Full Post »