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I have decided to describe all aspect of winter season fly. I have almost 20 years experience of such flies. For my opinion the winter season is the best one to fly remote control air models. The coldest temperature I fly was about 30 degrees below zero or may be some colder. I think it the coldest temperature in Saint Petersburg. |
Why the winter season is the best one? Let’s look the positive aspects:
We wave only one minus it is cold weather.
I don’t think that the outside temperature minus 15 - 20 degrees Celsius (temperature of freezing camera) can startle the people from northern countries.
Let’s start talking about the main part of winter season fly – it is clothes. It often isn’t underestimated by modelers.
The correct clothes are guarantee of successful and comfortable flies. Let’s classify cold weather by temperatures. It will be a little bit conditionally because it can shift one or two steps up and down due wind and sun radiation. It isn’t mistake, in calm sunny day it is rather warm.
The clothes has to be selected keeping in mind that modeler stands almost all time stock-still when he is controlling model.
A usual winter clothes will be enough for “Cool” only. If you have serious thinks winter flying about you will have to buy special winter clothes. You can buy them in any fisher/hunter shops or in a shop for builders or some there the same. Keep in mind that you have to select clothes for stock-still position.
If you have clothes for “Extreme cold” you always will be able to reduce it for more warm condition. I can’t sort out all possible variants. I will describe my own set with possible replacements for my opinion.
The set for “Extreme cold” and “Very cold” is the same. The difference is time of flying only. “Extreme cold” is one hour, “Very cold” till two hours.
I use Baffin Titan boots and thermo socks. The chipper set is felt boots covered with gum boots and wool socks. Gum boots are needed to protect felt boots from wet due melt of snow on the surface of felt ones.
I use thermo underwear and polar fleece semi combination. It can be changed by warm regular underwear and warm wool sweeter.
Don’t forget it about. It has to be long, high and woolen. The neck has to be covered with cravat wile you up your face.
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It may be used ensemble “Alaskan” or something the same for ice fishing. It is designed for long calm staying outside during extreme cold weather. It may be changed with wadded ensemble from store for builders. The back has to be closed. |
It has to be rather warm and to cover your ears. I use a fleece hat bough in a fishing store.
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It is strongly recommended to protect your eyes from the bright Sun and a bright sparking snow. The cold air contains a few amount of water and rather free from dust. The sunshine doesn’t have objects to disperse. Additional the sunshine reflect from white snow surface. If you can turn out from the Sun but snow is everywhere. |
It is the last element of your winter wear set. Properly made mufta allows controlling model with bare hands at any frost. The material has to have three coats. Upper coat should be water and wind proof, middle coat – warm material and bottom – lining material. You can follow any responses to not make or buy the mufta. You can take teenager’s old warm jacket with sintepon and with little redesign you will able to get the nice mufta. The second purpose of mufta is secure transmitter from water condensate when you will bring it to warm place after cold one. You have to keep transmitter in the mufta around two hours allowing slowly increasing the temperature of your transmitter.
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If the weather doesn’t “Extreme cold” some inner elements are excluded according the modeler’s opinion.
So, you have prepared all wears for yourself and your transmitter.
I want to note that the weakest element in winter season fly is servo. I have used servo High Tech, JR and Futaba with successful results. Below you can find the table of safe working time of servo according temperature.
The time is appointed approximately. The servo has to be checked before each fly. You should watch the speed. If you see the noticeable reduce the speed you have to avoid going into air. It is the best decision. Never try to reheat servo in a warm place. The servo will cover water condensate outside and inside. This water will freeze as you bring a model outside in cold. As result the servo will able to jam.
In my experience this time matches with duration of comfort staying outside in such cold condition.
I never have set models to winter season. Wheels have to be changed to skis only.
The skis from Du-Bro are very convenient. I tried them one time I transferred to them completely. It is possible making skis from plywood, cable channel or something else.
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If you are going to use homemade skis be carefully with attaching them. The skis have to be parallel to line of fly or have some angle up. This operation has one narrow spot. If you don’t have it in your mind you will broke l anding gear platform or it the first or in the second fly. In the worst case your model will be in crash.
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Test should be made the follow way. The model is left, you start to press to the nose of a ski, and the ski starts to rotate around axis. If the ski has chance to stay in position nose down you get this narrow spot. You have to research way to avoid this situation. Keep in mind that it should not be achieved with forth of spring or elastic but mechanically. If you don’t make it one of skis will be in this position when you will make some maneuvers such as spin, roll or other. It will produce a turning moment. This moment will be beiger with more speed of model. Even if you handle this situation the ski will deep to the snow as anchor and a base of lending gear with peace of fuselage or wing.
What do you do if it happened? First of all don’t panic. Try to make some maneuvers, it may help.
I have experience with electro and glow engines.
On my mind the electro model is the best choice for winter season fly. Therefore let’s start with it.
You don’t need to start and set motor. It is the main advantage.
Also the model is clear after fly and you don’t need to remove freezing oil from model.
I do not make anything with a model. I know that someone closes ventilation. They dread to freeze battery.
After a servo the weakest place is a Li – Po power battery. The capacity of the Li – Po decreases close to zero temperatures already. Therefore it can’t produce enough current for normal fly. Yes they warm up during the first few minutes and after this they can produce enough current, but they died very quickly in this case. Why it such happens? Without theory I can tell that in this case battery works close to short circuit mod.
To avoid this warm battery has to be inserted into the model. Somebody keep them close to body to warm up batteries from own heat. It works well if model doesn’t big and battery also. It will not work if model middle or big size with big battery. You can keep batteries in the working your car if it is parked close to you. What do you do if car is parked far away?
You can make a box with heating or insert heating in a car thermo box.
Heating should keep inside box temperature in 10-20 C range. Additionally the box can be placed into dark bag. It allows having some heating from sunshine.
The battery is brought out before fly and warm one is returned back immediately after using. It will bring up additional heat into the box.
I started up two strokes engines at any temperatures. Otherwise four stokes engines I could start up till minus 4 – 6 degreases. Wherefore I do not recommend using four strokes engine in winter season. Further I will describe starting and turning procedures for two strokes engines.
I used fuel with castor oil, synthetic and mix of them. I don’t have any doubt using castor oil.
If fuel is kept outside you should bring it to house and warm up it. The fuel has to be warmed up around one night. I strongly suggest opening a can and pressing it to close a cap. It prevents from increasing pressure inside the can.
You have to take more fuel at a field then you needed. This additional fuel will increase time of cooling the fuel. Also I recommend making some simple things to keep the heat of the fuel. It can be bag or something the same. Keep in mind the fuel will be refrigerated from surface of ground. Therefore use simple thermo isolation on can bottom at least.
It should be two items for successful start of glow engine at any conditions.
The more glow heating is requested due low outside temperature. Staring of engine may require more time. Therefore the glow plug heating device should have opportunity to work much longer without reducing of performance. Usual glow stick doesn’t fit for winter season. It doesn’t have enough power. You have to use power panel combined with good battery. The current should be set to right end of green sector or a little bit further. Make it carefully by small steps. Don’t burn the glow plug. You should stop increasing the heating of glow glug as soon as it starts flashing.
If engine doesn’t have enough fuel inside it never will start. Also engine has to rotate freely as at a summer.
It is very useful to have some soft small bottle with thin nose and some fuel inside. Some amount of fuel should be added into carburetor with following rotation of the engine. You have to do that until engine will rotate freely with a character sound. The more cold the longer you have to do it. If you use castor oil it will take more time.
An engine should be running some time with connected glow plug heating. If heating disconnects as soon as engine just starts it will shut down immediately. Therefore take 30 seconds or so on to warm up engine. he colder the longer heating should be kept.
Keep it in your mind that glow plug is under good cooling from cold air and fuel as well. You should make prolong interrupts between attempting to start engine. It will give enough time to heat glow plug. As usually you can hear a specific fizz from the engine. If you hear the fizz it’s mean that glow plug is heating. You have to wait until glow plug will reach hot stage.
It is very important to know what arrow of starting panel says.
What does it say? It says filling the engine about and preparedness of the engine to start as well.
Curiously enough it is rather effective style of winter engine start. I used follow procedure to start the engine. The engine is going to be flooded. It is archived by filling up to third portions of the fuel into carburetor. After that model is rotated a cylinder head down. Move prop from one to other side filling the combustion chamber with fuel until you will fill a hydro lock. Then the model has to be placed cylinder up or side to start. Rotate prop counterclockwise until it stops. Apply the glow plug heating, wait back movement of arrow on power panel and flip prop backward. The engine will make firing or start even. Such firing makes the engine warmer and it will start at last. You should watch power panel arrow all the time and wait backward movement of the arrow. The engine never will be started with cold glow plug.
You should achieve freely rotating engine when you will able to use starter. The engine has to be filling with fuel as described above. Keep in your mind that cold fuel has a bad movement through cold engine. Otherwise then engine makes firing a lot of fuel from a crankcase will bring to combustor camera. It leads to more cooling the glow plug. Watch the power panel arrow and wait glow plug heating before starter can be applied one more time.
If you are sure that engine has fuel inside, the glow plug has good heating but the engine doesn’t start and doesn’t make firings at all or it makes only one firing and after what you have to heat plug prolonged time – it means that the engine is totally flooded with remained oil. The model has to hold in position muffler and tail down. The fuel will flow from muffler.
A cold winter air is denser compare to summer one. It means that the same volume of air holds more oxygen. More oxygen enters into the combustor camera. We have to open needle valve to avoid running the engine too lean. If you don’t open needle valve the engine will stop in the air. The colder air the needle valve is more open. But when you open needle valve more fuel will enter into the engine increasing the cooling of it. Add to this more cooling from cold air compare the summer. If performance of reached engine decreases in summer season in the winter season it will shut down due overcooling.
How you can separate two causes of shutting down engine? Does it reach or learn?
And what side you must rotate needle to achieve god performance of the engine?
If the engine shut down on vertical pass it means what engine too lean and you have to open needle valve. Otherwise if the engine shut down after prolonged level fly it means what the engine too reach and you have to close needle valve.
Sometimes it is impossible to achieve properly tuning the engine. It will shut down on vertical and level fly as well. It means that engine can’t to warm up till normal working temperature. You have to reduce cooling the engine. It can be achieved two ways.
I have not watched any affect low temperature to idle setting.
If you use glow engine the best decision is fly nonstop. Warm engine starts easy as in a summer season. The flying day has to have such scenario start – setting – take off – flying – landing – taxing to a pilot – shutting down – keeping heat of engine with peace of towel or something the same – filling fuel tank – removing towel from the engine – start – take off and so on.
If you interrupt this conveyor and the engine cooling down to the outside temperature you will have to start engine again.
But start the glow engine is the toughest part of glow engine winter fly.
There are five different snow surfaces. Each of them requires different types of taking off.
Usually such surface is happen when thaw is changed by frost and at the end of winter in the morning after night frost. It is the best conditions. The model takes off as in the summer season. Only one difference – model stands on skis instead of wheels.
The model scarcely holds on the surface of snow. An electro model will take off almost the same as in the first case. The main feature is soft start to gain speed without falling skis below ice crest. If you apply throttle sharply the skis can fall down under the ice crest. If it happened do not try to take off. It is almost impossible to break the ice crest with skis. The best decision will stop the engine and get model on snow surface with your hands. After this you can try to start again.
The nitro plane is a little bit difficult to be airborne. The right ski will fall down ice crest due vibration from running engine on idle while left one will stay upper. When you try to start taxing the model will rotate around the right ski. To avoid it you can hard surface around you are starting or try to find peace of hard surface. Additionally apply throttle gradually and be ready to move steak back.
Both type of models.
As soon as model reaches some speed you can apply full throttle to gain flying speed. Usually it is taking one or two meters.
Ski fall down into snow on 2-5 sm. A nitro model will bank to star board due vibration. You should very slowly apply throttle holding up elevator to avoid down nose of the model. As model will gain it speed and skis will rise on a snow surface you should release up elevator. If model starts to fall down in snow you should release the throttle and to put the model on a snow surface with your hand. As soon as skis will glide on the surface of the show apply full throttle to be airborne.
Very sort snow will be after a snowfall right now. This kind of surface doesn’t hold the skis completely. The model will hold on the surface with whole wing only. In this case you have to prepare some place for running. If you thought shovel about you would mistake. Nothing special does need. It’ll take 15-20 minutes only. You have to determine a direction at the first to the wind of course. After that you have to make a sector from you to the wind with your feet. It should be 15-30 meters long. Then you are going the show will be destroyed and also it is well kneaded. You may hard the starting place with your feet additionally. It takes around one meter. All it should be enough.
You should apply full throttle at once. Of course if you prepare surface 60 meters long you will able to apply throttle gradually.
The model has to be airborne in borders of this sector. Keep in your mind that new snow doesn’t hold model at all and it produces a lot amount of resistance. It doesn’t allow model to be airborne.
Such type of snow is happened when show is wet after or during winter rain. It is one condition when I do not know how take off the model. The skis fall down into snow and you have not a chance to accelerate model to fly speed due high resistance of a snow.
The main difference from summer season is harder touching down. Landing gear have not bumpers from gum’s or hard foam’s tires. Therefore try to touch down softer.
I hope that this article will help you to be a master in such interesting winter season flies.