|I want to fly R/C. How do I get started and how much will it
If you have access to a local R/C Hobby Shop and/or a local R/C Flying Club, start visiting them and get yourself known. Don't jump right on them with a lot of questions, but ease up on the people and when they see that you are serious they will provide you with very helpful advice and services. There are many good trainer planes (not a "P-51" for your 1st) on the market, but if I had to pick one to start with,
go with the Great Planes "PT-20 or PT-40". You can get it in a "Almost Ready to Fly" version (quick to get ready to fly) or in a build it yourself version (takes a little longer, but you learn more about the plane and will be able to fix it when the 1st crash happens).
Engine - You generally get what you pay for here. Don't get the cheapest one or the highest price one for your first. See what the flyers
in your area are using (they will be helping tune it for you). Some good old time brands are "OS", "Enya", "Super Tiger". More important is
how you treat it. Read the instructions several times and be prepared to follow them before you crank it for the first time. Most important is to have the pluming correct from the fuel tank to engine and to give it a nice easy rich break-in run time before you try to tune the main needle
valve for max. power.
Radio - For your first radio, go with something simple (four to six channel, AM or FM, non-computer) Good brands are "Futaba", "JR",
Cost - For everything that you will need to get started, get ready to spend about $500 -- $600.
Most important is to see what is being used in your area and what works with your local modelers (they will be able to help you better).
Why does my new, never been crashed, engine have a high freq. vibration even with a balanced prop?
Some engines are under counter-balanced; that is, the counter balance on the crankshaft does not have enough mass to completely balance the piston when the piston is at "top dead center" (TDC). Every time that the piston goes to "TDC" and crankshaft counter-balance is at the bottom of crankcase, then the piston is effectively heavier than the counter-balance. With this condition occurring thousands of times per minute, we have a high freq. vibration. What can you do about it? Try this. Take a prop and put it on your prop balancer, but don't balance it. Just mark the heavy end of prop and mount the unbalanced prop so that the heavy end (marked) is 180 degrees opposite the piston when the piston is at "TDC". In other words, when the piston is at its closest position to the glow plug (up), the heavy end of prop must be exactly opposite (down). This will help balance the heavy piston, and may solve your vibration problem. If it doesn't, balance the prop and try something else because that was not your problem after all.
How does a Tuned Pipe exhaust system work with our two stroke model engines?
1 - When the piston comes down far enough for the exhaust port to open, the burnt gases exit into the tuned pipe. As the gases reach the
expanding part of the pipe they accelerate and draw more burnt gas out of the engine.
2 - As the piston continues down, the intake ports open and a fresh charge of gas enters above the piston and also helps push the BURNT gases out.
3 - The fresh charge has now pushed out the burnt gases AND some of the fresh charge has also gone through the exhaust port. NOW....The burnt gases have reached the rear of the tuned pipe and a pressure wave is reflected back toward the exhaust port.
4 - The piston is now comeing back up and the intake ports are closed BUT the exhaust port is STILL OPEN. The pressure wave PUSHES
some of the fresh charge (which had exited behind the burnt gases) BACK into the engine. This action SUPERCHARGES the engine from
the exhaust side and enables the engine to provide more power. For optimum performance, the reflective end of the tuned pipe must
be at a particular distance from the engines exhaust port for each engines timeing and the type of fuel used. A tuned pipe is TUNED for
a particular engine by adjusting the lenght of the exhaust header in order to get this critical distance just right.
For an engine to be pipe timed (able to benifit from a tuned pipe) the intake ports must be closed by the piston as it comes up BUT the
exhaust port must still be open for a period of time before the piston continues on up and closes the exhaust port. The compression of the
now supercharged fuel-air mixture begins and Wham-O, More Power!!.
What does Air Flow have to do with my models control surfaces?
Control surfaces are completely ineffective unless there is a flow of air over them (as when on the ground on a windless day). Their efficiency
is related to the speed of the air flow over them. It is because of this that you have little control over an aircraft which bounces high on
landing. There are some maneuvers which are difficult to perform owing to this fact - such as a tail slide, a stall turn, and entry into a spin.
At your highest point of climb, immediatly prior to dropping back, your aircraft is completely stationary in the surrounding air. You have a little air flow over the tail surfaces from a slow running prop, but not enough for adequate control. Your ailerons are useless at this stage. So, how do you achieve a stalled turn? You either cheat a little and climb slightly to either side of perpendicular, or open your throttle a little at
the top of the climb to give some tail end control. This will also help with a spin entry and on that high bounce landing, give it some throttle
(if you have any left) to get that air flow going again over the tail surfaces.
Now that the "Y-2-K" is upon us; what new R/C Hobby inventions can we be looking forward to in the future?
1 - A motorized lead screw and weight that adjusts the CG forward as the fuel is used up.
2 - Special tires designed for better tracking through horse pies!
3 - A safety device on the transmitter that prevents engine Rev-up if your palms are too wet with sweat.
4 - A voice activated device on the transmitter that responds to the words "I ain't got it" and answers back "Yes you do" or "No you don't"
whichever applies at the time.
5 - A self-balancing prop washer that sheds particles from its outer perphery until perfect dynamic balance is acheived.
6 - A radio that gives off very bad smelling fumes if left unattended for more than two days after being shipped back to the manufactuer for
repair. This should encourage faster turn around service.
7 - A wing tip mounted hoop for trainers that changes cartwheels into Merry-Go-Rounds.
What went wrong? Why did I crash?
When did you last check your radio batteries? Would you go hiking in the "Sahara" with just half of a canteen of water? Do not go flying
without being sure that your batteries are in good condition and are fully charged. Check the battery voltage under load and if the voltage
has dropped to a un-safe level, give them a quick field charge or stop flying for the day. When cleaning your aircraft, do not use any cleaning product which contains Ammonia. Ammonia will cause the wireing in your radio system (particularly in the switch or charge jack) to corrode and fail at some time. Check all screws; especially engine, muffler, and servo screws to insure that they are snug. Don't forget those wheel collars, kwik links, and control horns. Check all control surfaces to see that the hinges are secure and that none of the internal linkages are loose or getting sloppy. Look for any signs of stress or structural failure and check the radio plugs and all wireing for any signs of chafing due to equiptment shifting inside the fuselage. At the field, re-confirm your radio range with the aircraft assembled and check that the control surfaces are still working in the correct directions. Open the needle valve slightly to insure a rich setting on start of engine. Lean just into a two-cycle at full throttle and confirm setting by holding nose vertical. In adjusting your engine - remember - what you are after is not peak power, but good power with peak reliability! With engine running, check the fuel line for any sign of bubbles which would indicate a hole in the fuel line somewhere between the carb. and the pick-up klunk in the fuel tank. A leaking fuel filter or fuel foaming in the tank from excess viberation will also cause bubbles. When flying, think throttle at all times!! If you get into trouble, cut the throttle first and then try to figure out your difficulity. Think of the sky as a funnel with the flying site at the bottom. That is....The further away you fly, the higher you should fly. Getting into trouble at low altitude far from the field is almost always a sure way to court disaster. Always know your radio freq. and use the freq. control system at the field where you are flying at all times. Try not to fly beyond your ability and ask for help if you are in doubt.
My plane is a mess! What can I do about that leaky two piece muffler?
1 - Remove the nut & bolt that holds the muffler together and thoroughly clean all muffler parts of oil and exhaust residue.
2 - With sandpaper, ruff up the areas where the muffler halves mate as well as the holes where the long bolt passes through each end.
3 - Apply "J-B Weld" brand (24-hr.) epoxy glue to the mating areas of muffler parts and the holes where the long bolt goes.
4 - Re-assemble muffler. Important Note!! Be certain that the muffler exhaust outlet is pointed in the direction you desire at this stage as it can not be adjusted after the "J-B Weld" cures. Be sure that you have sealed the areas around the head of the long bolt and the nut on the other end with glue.
5 - Upon re-attachment of muffler to engine, use a gasket or a thin smear of Hi-Temp. Silicone Sealant between the muffler and engine exhaust stack. This procedure, with perhaps the use of an angled exhaust deflector should take care of your leaky mess.