Ribcrackers Model Airplane Club We re on the web! http:/www.ribcrackers.org Club 2067 June 2010 Thunderbolt President s Message Gus Dabringhaus It is hard to believe that War Bird Weekend is this Sunday. Wasn t just two weeks ago that our first fun-fly just couldn t get off the ground? Dennis had come prepared complete with all sorts of crazy things to do, however the wind would have no part in it. I think that the electric foamie planes would have ended up in the next county and to the best of my knowledge there was not an event for long distance on the list. Big thanks to Dennis for his effort. The field clean up was not perfect weather either. I might have imagined the snow flakes but it was cold and windy to say the least. I wish we would have cut a few more trees especially now that the leaves are in full swing but we will get them some other time if required. I remember about ten out of sixty hardy Ribcrackers present and their help is much appreciated. I have only good things about the condition of our field. If we keep the continuous improvements, we might start to have some migration from the other clubs in the area. How does every one like the new wind sock? I think that it is just right. From snow to the eighties in just three weeks. The student program has taken off to a good start. The first week was shaky and I m not talking about the students thumbs, the temps were in the fifties and windy but a couple of teams got in some flights. The mix between instructors and students seems to be a little more than one to one. Rumor has it that Greg might have to buy the beer soon. He can take off and he can land. No Greg it is not either or for your sign off, its both, in the same flight. Warren reports that he is close. The new members seem to be exited as well and the turn out is a little better then in the past. I even saw our vice-president not just helping out on student night but he actually flew a plane. Maybe this is just like riding a bike. I heard that he flew a couple of flights on his Machii over Memorial weekend and as of last night; he only had a small scar on his forearm. Its nice to have him as a volunteer plus that fact that he can still fly makes Hank an all around good friend. Well now that we are starting what should be a great new season, everything seemes to be well under control with some minor mishaps along the flight path. Its always sad to hear about the ground jumping up to realign some of the planes. I had hoped that more of the spiritual request would have been heard to prevent that sort of thing from happening. Keep putting in a good word and that along with our own skills; we should not have to buy the big bottle of glue for the summer. Good luck to all and try to keep that bag of shame unused and in the car. Rudder reports a tom cat hijacked a plane, shoved a pistol into the pilots ribs and demanded: take me to the canaries. Gus June Club Meeting Monday, June 7, 7:30 pm Ray Field 55495 Grand River, East of Milford Rd
MAY 2010 Model of the Month. And the winner is Dennis Kirwood and his Slowpoke. Runner up Roger And his restored Beaver Ribcrackers 2010 Board of Directors President Gus Dabringhaus 810-986-0375 810-222-6300 fax gdabringhaus@comcast.net Vice President Hank Wojcik 313-659-1677 oaklandbolt@aol.com Secretary Matt Jerue 248-348-5948 mdjerue@mi.rr.com Treasurer Dennis Robbins 248-661-3562 drobbins421@yahoo.com Librarian Ken Hilton 248-374-8259 CLUB POSITIONS Thunderbolt Editor Don Unsworth 248-348-0961 dunswrth@sbcglobal.net Field Marshall/Safety Officer Alex Alexopoulos 248-909-6869 Chief Instructor Warren Wells 248-437-2694 Minute Recorder Gerald Klose 248-582-1803 Raffle Coordinator Warren Wells
Ribcrackers April Meeting Minutes - May 3, 2010 Meeting called to order at 7:31 It was decided to go ahead and try and cover as much material as possible to try and beat the rain while still waiting for people to come from the Livonia Senior Citizen Center. Minutes from last month were unanimously approved. Treasurer s report: We are currently $600 down from the projection. We had the field rolled for $300 and it helped a lot. The porta-potty is getting serviced once again. The field looks good. It is currently being cut on Friday. There was a discussion whether to move the cutting to Wednesday so that the grass wasn t so long for Student night but it was decided to leave it on Friday. Secretary s Report: If you have already paid but don t have your card yet you might try checking in the field box. There are new starter packs available in the field box. We had left a list of members that had paid to help police the people to fly but it was surreptitiously removed. Therefore, NO CARD NO FLY Editor s report: Regarding the club covering project: Ralph will cover the wings and ailerons, Roger will do the fuselage. An engine will be donated and once the plane is complete it will be raffled off. There will be continued discussion regarding the club build project. Once we get closer to the build season we will finalize the plane that will be built. New/Old Business This weekend is the field cleanup. There will be some trimming of trees to improve the approaches. Orange plastic fencing will be removed and replaced with metal fencing for increased safety. There will new flight stations (patio stones) placed behind the fencing to finally table the discussion of whether we stand in front or behind the fence while flying. The canopy will be put up on the shelter frame. Gus has a source for white material that can be used to make a center line down the runaway. Field work is expected to commence at 9:00 am. Remember that on Student night students get priority on the flightline. Members can fly if there are no students waiting. First fun fly is 5-16 Make sure take you take your garbage home. Don t leave it in the cigarette cans as it tends to create fires. Someone left a Field Box at the field. If anyone knows of the owner I am sure they would be delighted to be reunited. Model of the Month: Dennis Kirwood brought in a Slowpoke kit with a cool original covering scheme powered by a Saito 4 stroke Roger Wilfong brought in a Beaver that he rescued from the garbage can. It was re-covered in a scheme that resembled a full scale plane. Roger put the flaps channel on a rate reducer that gives it a realistic look. Pretty trick! Congratulations goes to Dennis!! For the Raffle we had a Turnigy Battery charger and the Foam Spitfire made a re-appearance and went to a new happy home. Tenaciously submitted by Gerald Klose Obediently submitted by Gerald Klose
Roger s Ramblings Picking the Power System Roger Wilfong #13 in an ongoing series Last time I covered figuring out how much the 4-Star-380 needed to weight to have the basic flight characteristics of the 4-Star-40. But to perform like it s bigger sibling, the 380 is going to need to have similar power to weight and wing area. To figure that out, we ll look back to earlier columns and use some of the rules of thumb that the electric pioneers developed. Here are the starting assumptions for selecting the power system Wing area = 380 sqin Weight = 38oz Stall speed = 15 mph Battery = 2300 mah A123 cells. First we need to figure out how many cells we need. We ll use Orme s Law for this, It takes 6 Watt-Hours/100 sq-in on a low wing pattern plane for 8-10 minutes of good performance. So plugging in the numbers Energy = WingArea sqin * 6 W-H/100 sqin = 380 * 6 / 100 W-H = 22.8 W-H The 2300 mah A123 cells I want to use have 7.95 W-H of energy per cell so if we divide the 22.8 W-H by 7.95 W-H/cell we ll know how many cells we need. That works out to 2.8 cells which we ll round up to 3 cells. The next thing we want to figure out is the power needed. We ll use Shaw s rule, It takes 80+ watts/pound for unlimited acrobatics to figure that out. Since our target weight is 38 ounces (2.375 pounds), we ll need 190 watts to reach the magic number of 80. Anything more is just extra performance or longer flight time since we can run at reduced throttle for more of the flight. Remembering back to the early columns, power (watts) is just voltage times current so to got our 190 watts, we simply need to pick a voltage (number of cells) and then adjust the motor and prop for the current we need. For the 4-Star-380, I m planning on using the A123 cells (from above there will be 3 cells in the pack) and an old Astroflight 035G. So the motor and the battery are fixed, but I can select the prop to give me the needed power (we also need to select the prop for other thing, but we ll talk more about that later). A three cell A123 pack will have a terminal voltage of about 10 volts under load, so to get 190 watts, I need to select the prop that will load the motor to 19 amps. Actually, both the A123 batteries and the Astro 035G are good to 35 amps, but I like to keep them between 25 and 30 amps. So, I ll shoot for a prop that loads the system in that range. One thing we haven t talked about too much is prop selection. In an earlier column, I mentioned that prop selection can affect the load on the motor and consequently the current draw (the larger the diameter and/or the higher the pitch, the greater the load and current draw), but there are other consideration in selecting a prop like will it fit on the plane for one. Next time we ll plug the numbers above into a prediction program and look more closely at prop selection. NANKIN HOBBY Reconstruction has started on the Farmington store. A late June or July open for business is targeted. The summer fire sale is a no go due to insurance stipulations.
Again, the weather it just wasn t a good day for a fun fly competition. So, the decision was made to open the field for general flying. There were some great looking planes appearing from vans and a trailer. The Ribcrackers were busy this past winter. Matt Jerue had a maiden flight with his good looking red, white and blue plane. Plane and pilot performed admirably with a little tweaking on the elevators. Spring Fun Fly The next fun fly is scheduled for Sunday, June 6. Warbirds Over New Hudson. Photos by Greg Kostyniuk Spring Clean Up Despite wind gusts of 40 mph and spitting rain, twelve hardy souls turned out for this years spring clean up...camaraderie prevailed! New flight station fencing was installed with the pilot station cement pads located on the pit side, complying with the May meeting vote. Matt brought coffee and donuts, Louie brought his daughter to supervise and to keep an eye on his car keys while Dennis entertained Radar and Sam by throwing tennis balls onto the runway. Ray field is looking good, ready for the new season. I didn t collect names, but to those of you who were there, remember that the CLUB is most appreciative of your efforts. Thanks for a job well done. Don
RIBCRACKERS STUDENT NIGHT 6:00 pm Every Wednesday night Warren Wells 248.437.2694 Ribcrackers Summer Events June 6 Fun Fly / Warbirds, Gus, CD LOCAL COMING EVENTS June 5 & 6 Keith Shaw B-Day Electric Fly-In Balsa Butchers Coldwater, Michigan Dave Grife,CD 517.279.8445 grifesd@yahoo.com June 5 Warbird Fly In White Lake MI Dae McDonald, CD 248.363.7277 www.pmac.us June 12 UFO Field Highland Township Swap, Buy & Fly Dan Wamboldt, CD 734.433.5451 danrcpilot100@aol.com July 18 Fun Fly / Picnic, Alex, CD August 15 Fun Fly September 12 Fun Fly Many events are planned for the summer. For a complete list see pages 152 157 of the June issue of Model Aviation. Starting with the July issue the calendar of events will no longer be in the magazine; only on the web page. See the May issue for specifics. 895 Grace, Northville, Michigan 48167 Upcoming Fun Flys The club has four remaining FUN FLYS for this season; Sundays, June 6, July 18, August 15 and Sept 12. Consider coordinating one of them. The club s website lists several events and all are explained in detail. All you have to do is pick 3 or 4, set up the rules and the scoring, then leave it up to the pilots and spectators to make it a fun time. Lou Courter is selling his father in law s collection of planes and equipment. He can be reached at the address below. Planes & Equipment Lou Courter 10404 Bridgewater Drive, South Lyon, Michigan 48178 248-231-8552