Sizing your Model s Prop

Transcription

1 Word of the Month: By-Lines & Fly-Lines P.O. Box 569, Lakehurst, NJ May 2017 Sizing your Model s Prop Fun to Experiment with Different Propellers T he manual for every engine will give you a range of propellers that is safe to use with that engine. The manual does not specify the exact size propeller because the propellers must be sized for the airplane they are used with. It is very important to stay within this recommended range. The propeller puts a load on the engine. If the load is too small or too large it will damage the engine. You must choose a propeller within the recommended range that best suits your airplane and your flying style. The characteristics of a propeller are defined by the diameter and the pitch. The diameter is the distance from one tip to the other. The pitch is defined as the distance the propeller would move the airplane forward in one rotation in a perfect world. Perfect world meaning that the propeller is 100% efficient and the air does not compress; neither of which is practical in the real world. The twist of the propeller is what determines the pitch. Basically the length of the propeller and its twist defines its characteristics. A model airplane propeller size is always referred to as its diameter x pitch. An 11-inch diameter propeller with a 6-inch pitch is called an 11 x 6 propeller. Generally speaking, the larger the diameter of the propeller the more thrust will be produced by the engine. The larger the pitch the more speed you will get out of your engine. A small diameter, larger pitch propeller will move a small volume of air really fast. A large diameter small pitch propeller will move a large volume of air at a slower speed. Increasing either the pitch or the diameter puts a larger load on the engine. To keep the proper load on the engine, you generally change the pitch and diameter together. For example, 9 x 7, 10 x 6, and 11 x 5 propellers would all put a very similar load on the engine. If you want to change the maximum RPM, then you change the load on the engine. Replacing an 11 x 6 propeller with a 10 x 6 propeller, or replacing an 11 x 6 propeller with an 11 x 5 will decrease the load on the engine and raise the maximum RPM. Changing from a 10 x 6 to a 10 x 7 propeller, or changing from a 10 x 6 to an 11 x 6 will increase the load and lower the maximum RPM. If the propeller load is too large, the engine will not turn fast enough to fly the airplane see Sizing, page 2

2 Page 2 Club Officers PRESIDENT Edward Hollema Ehhol@aol.com VICE PRESIDENT Joseph Acquisto Jwa1956@aol.com TREASURER Tom Moore Tmoore1801@aol.com SECRETARY Vince Scatuccio vscatucc@gmail.com SAFETY OFFICER Tony Riccio ARiccio1@yahoo.com NEWSLETTER EDITOR Sue Fevola ocmrc@yahoo.com PROPERTY MANAGER vacant CLOTHING APPAREL Vacant WEBSITE ADMINISTRATOR Vince Scatuccio vscatucc@gmail.com Definition for Word of the Month:, from page 1 NOTICE OCM Meeting Wednesday May 24th 7:00pm Manchester Municipal Building could cause the engine to overheat. If the load is too small the engine will turn too fast damaging the engine. So it is important to stay within the window recommended by the engine manufacturer. It is also important to know that the engine must be turned each time the propeller size is changed because of the change in load the engine sees. When choosing a model airplane propeller you must keep in mind that you are choosing the propeller based on how you want the airplane to fly. This really has nothing to do with the engine other than the fact that you must stay within the recommended window of propellers to prevent damaging it. The same engine used on two different airplanes may be using two completely different propellers. If you have an airplane with low drag designed for speed then you will want more pitch. If you have a slow airplane with a lot of drag, such as a biplane, you will want more diameter (thrust) and less pitch (speed). Choosing a propeller that best fits your airplane and your flying style is a trial-and-error process. Pick up several propellers within the recommendation range. If your airplane seems too sluggish when taking off and accelerating, then change to a lower pitch, larger diameter propeller. If your airplane has plenty of pep and you want to make it go faster, then change to a larger pitch, smaller diameter propeller. It s really fun to experiment with different propellers and observe how the airplane reacts. [reprinted with permission from The Tailwind, Hendersonville R/C Club, TN, July 2016]

3 Page 3 Minutes of OCM Meeting on April 26, 2017 P resident Ed Hollema called the meeting to order at 7:05pm after the Pledge of Allegiance. Secretary Vince Scatuccio called for comments or corrections to the minutes of the March meeting that were published in the newsletter. The minutes were accepted as presented, after the normal motion, second, and vote process. The membership total stands at 93 paid members, with an additional 13 junior members. Thirty members attended the meeting tonight. The four new members were introduced to the membership: John Jacobson, Bill Horak, Michael Lobwoli and Peter Rozewski. Vince gave the Treasurer s report in Tom Moore s absence. He reported the beginning April balance of $10, and as of the April meeting the balance is $10, This does not include money received from the new members. Safety Officer Tony Riccio stated there were no safety issues to report. However, the shed was left unlocked on one occasion. Please remember to lock the shed, storage container and gate if you re the last one leaving the field. On April 8th 15 members came out for the field work day and filled holes on the field, built two new work benches and a new starter table. He thanked those members who helped. OLD BUSINESS: Ed talked about the following 2017 events being scheduled: Auction: scheduled April 29th. Mike Cook is looking for volunteers for the event. Pattern Contest: scheduled May 20th. Sal is looking for volunteers for the event. Community Day: scheduled September 9th. Mall Display: to be scheduled. Steve Lew contacted the Ocean County Mall for a second time and is waiting for a response to find out if they are interested. 3D Event: the 3D event has been canceled as originally planned. A fun fly including 3D, war birds and other activities will be scheduled in October instead. NEW BUSINESS: Vince informed the membership that the club has been awarded the AMA Leader award for Mike Cook is planning a CPR seminar, no date announced yet. Vince gave an update on the FAA seminar he attended. The FAA has built an app B4UFLY to check for restricted airspace before flying. If you are in a restricted area you must notify the air field. This does not include flying at Wiskow field. see Minutes, page 4

4 Page 4 Minutes, from page 3 He also mentioned that the Jackson high school scholarship committee has received our donation in the amount of $500. It will be awarded to a qualifying student at a June 5th ceremony. Since all cell phones are now digital there is no interference with 72 or 2.4 MHz radios. The membership voted and agreed to remove the restriction from the club rules. The membership cards will be updated with the date of your AMA expiration date. This is due to an AMA change in registration for members from year-end date of expiration to the month your membership begins. Ed mentioned the new signs for the flight line will be made. Also new stone will be placed on the roadway and the field will be rolled. This is being scheduled prior to the Pattern contest on May 20th. Bill Bollard informed the membership that the STEM program with CAP is scheduled for May 24th. Vince informed the membership that the AMA awarded $48,000. in scholarship money to 11 high school graduates from across the nation. He reminded everyone if they have children or grandchildren who are members of AMA and nearing college age, to apply for the scholarship for Also, if you received the survey on the AMA East expo held recently, please fill it out and submit it. CRASH OF THE MONTH: Mike Cook presented Lou Agoston with the Crash of the Month Award for crashing his Soarstar. MODEL OF THE MONTH: Bill Martin showed his completed Taylor Craft. It has a wing span of 108, cost approximately $1,200. and it took eighteen months to build. There was no 50/50. The meeting was adjourned at 8:25pm. Submitted by Vince Scatuccio, Secretary Pattern Contest Saturday, May 20th Contact: Sal Piu, for additional info or to volunteer Origin of Common Expressions In George Washington s days, there were no cameras. One s image was either sculpted or painted. Some paintings of George Washington showed him standing behind a desk with one arm behind his back while others showed both legs and both arms. Prices charged by painters were not based on how many people were to be painted, but by how many limbs were to be painted. Arms and legs are limbs. therefore painting them would cost the buyer more. Hence the expression, Okay, but it ll cost you an arm and a leg.

5 Page 5 Sometimes you Just Have to Laugh... The barber s client looked depressed, so the barber told him, cheer up. I knew a guy who owed $5,000 he couldn t pay. He drove his vehicle to the edge of a cliff, where he sat for over an hour. A group of concerned citizens heard about his problem and passed a hat around. Relieved, the man pulled back from the cliff s edge. Incredible, said the client. Who were these kind people? The barber replied, The passengers on his bus. Tips and Tricks Rib Holder Get a piece of aluminum 1 or 2 inch right angle that can be found at most hardware stores. Make sure it is really square (90%) then cut off 1/2 inch wide pieces. Next drill small holes in each end about the size of a push pin or T pin. Use the angles to hold ribs perpendicular to the building board by putting one on each side of the rib and then pinning it to the board. Balsa Filler Don t buy filler from the catalogs, go to Wal-Mart, Lowe s, or Home Depot and get lightweight spackling paste it s cheap and comes in a large container. When it starts to dry up, just add a little water and stir with a popsicle stick until you get your desired consistency. Crash of the Month Mike Cook presented the Oops award to Lou Agoston for crashing his Soarstar.

6 Page 6 After 18 months Bill Martin and his team (Chris Segui, Victor Czornyj and Dennis Haase) completed the building of this beautiful Taylor Craft BC-12. It has a 108 wing span and is 21 pounds. The motor is a DLE-35RA and the radio is a Hitec. The prop is 19x10 and the battery is a Life. It has navigation lights as well. Do you know what makes a double rainbow? It is the result of sunlight bouncing off the inside of a raindrop for a second time, which explains why the colors are reversed and less bright.

7 Page 7 Things you Probably Never Thought About Y ou see people every day that you ll never see again. Your age is the number of times you ve orbited around the sun. You have never seen your face, only pictures and reflections. The Turritopsis Dohrnii Jellyfish is able to revert to an earlier stage in its development cycle in order to cheat death. The oldest person in the world was born with a completely different set of humans. One hundred years from now, Facebook is going to be full of dead people. We judge ourselves by our intentions and others by their behavior. All planets in the solar system fit between the earth and the moon, the sun does not. If you looked at the earth 65 million light years away you would see dinosaurs. If you properly shuffle a pack of cards, chances are that exact order has never been seen before in the whole history of the universe. A million seconds is 11 days. A billion seconds is 31 years. Mars is the only known planet in our solar system solely inhabited by functioning robots. There s no reason for the alphabet to be in that order. If you re lucky, your internal organs will never see the light of day. Outer space is only an hour s drive away if your car could drive straight up. You re not stuck in traffic; you are the traffic. You re totally blind for hours every day, but Saccadic Masking renders you totally unaware of it. Russia s area is bigger than Pluto s. The human brain is one of the most complex things known to man...according to the human brain. Mammoths still walked the earth when the Great Pyramids were being built. Every single choice you have ever made in your life has brought you to this exact moment, reading this exact sentence. There are more bacterial cells in your body than human cells. We built an atomic bomb twenty years before we had color television. Everything you see is delayed. Electrons actually pass through wires very slowly the reason it seems quick is the same reason if you had a tube full of marbles and you pushed another one in, one would nearly instantly pop out the other end. At some point you will be the next person on Earth to die. Welcome to our New Members Bill Horak John Jacobson Michael Lobwoli Peter Rozewski

8 Page 8 JACKSON HOBBY SHOP Full Line Hobby Shop The Parts & Service Specialists New items arriving daily STORE HOURS Tuesday thru Friday: 11am-6pm Saturday: 11am - 5pm Sunday & Monday - Closed Show your OCM club card for 10% discount. (See store personnel for details.) We carry Lionel trains for the kid in you L.G.B. G GAUGE INDOOR OUTDOOR TRAINS JACKSON HOBBY SHOP 2275 W. COUNTY LINE RD (RT 526), JACKSON (IN BENNETTS MILL PLAZA) Credit cards accepted Established 1969