Motive-Power

Electric Brushless motors:

The go too choice if you are into electric power and relatively easy to get high power. Better in noise sensitive flying sites; although very, high revving props can still produce a lot of noise. The right size battery and prop combination play a big role in the final outcome.

Note: Aliexpress is fertile hunting ground for motor and power information most (not all) of the sellers have charts of information for motors that will give voltage, power, Esc size and prop sizes,  on the web pages, and also for EDF's. All valuable info,  this is something that a lot of western vendors seem to omit or not care about. It's well worth nosing around AliExpress as a lot of OEM's (Original Equipment Manufacturer) sell their motors there. If you are canny enough to note the sameness between branded motors and OEM motors, usually the specs are identical, one just has a brand name label stuck on it; money can be saved. I learned quite a lot, as well as bagging the occasional bargain.

Zoe Quilter

What follows  are the actual motors I use,  NOT!  hard recommendations,  there are many choices shapes and sizes;  But I do know from experience it helps to know what others are actually using if you  just want to get started.

The above are made in a range of sizes and badged with many different brand names. My Brodak Tigercat uses 2 1500KV motors. Prop recommendations delightfully described  as paddles!

XXD A2217 2217 950KV 1250KV 1500KV 2300KV Outrunner Brushless Motor For RC Airplane Aircraft Plane Quadrocopter Multi-copter

￡17.32 

Price includes VAT

Color: A2217 KV1500

Item: XXD A2217 950KV/1100KV/1250KV/1500KV/1750KV With Motor Mount

Parameters:

Dimension: 27.8 x 32 mm

Weight: 85g appr.

Shaft Diameter: 4 mm

Accessories: 4.0mm prop adapter, motor mount, screws

Features:

Prop Recommendation:

950kv motor is suitable for 11 inch or 10 inch paddles, such as 1155 1070 1050 1060, etc.

1100kv motor is suitable for 10 inch paddles, such as 1070 1050 1060, etc.

1250kv motor is suitable for 9 inch paddles, such as 9050 9045 9060, etc.

1500kv motor is suitable for 8 inch or 9 inch paddles, such as 8040 8060 9045, etc.

1750kv motor is suitable for 7 inch paddles, such as 7050 7035, etc.

Package Included:

XXD A2217  brushless motor x1

4.0 paddle clamp x1

22 series  plastic motor mount x1 (Not sure what this refering to?)

The fuel, so to speak, is electrons. there is no fixed rule on battery make or type, although I don't think AA batteries would work to well...😁

A LiPo battery of sufficient capacity to fly a single contest flight is ideal, as you will not be carrying around any extra weight. Coming from RC flying you may be surprised how small a battery you actually need. Ending with between 10-20% charge is good; however, this will mean, either more than one battery being available, or charging between flights. either is  preferable to doubling the weight of a battery.

Number of of cells depends on the motors KV rating, what the ESC can handle, size and pitch of the prop. The motor manufacturer will usually have all this information to use as a starting point.

If beginning there is no harm in using cheap 3 cell batteries to cut your teeth on. Not! literally of course, that would be a very unwise thing to do, causing a bit more surprise than licking  9v battery terminals. Many Basic and Junior Class models will still fly well on 3 cells, only missing out on the fast run; but as the scoring is biased towards slow speeds, this is not as bad as you might think. The only downside to cheap low C rated batteries is, 'sagging', only able to sustain maximum current  draw for a short period. This not too serious a problem unless it happens within a few seconds of leaving the deck.

4 cells is sweet spot for competition. Unfortunately a bit of suck it and see is needed until you can work out the best combination of battery and drivetrain. Good quality batteries help a lot but tend toward being expensive. 

EDF (Electric Ducted Fan: 

Well known to be inefficient compared to propellers. Main challenge is getting a sufficient power to weight ratio to get them to fly reliably in a wide range of conditions with primarily enough thrust to get off the short length of a deck in the first place. This is the biggest hurdle. Lots of room for experimentation and trial and error development. For now CI Posta Class is probably the best place to experiment with them.

A compromise on cells is 5, they will work on 4 but struggle, 6 would be ideal but then weight can become excessive. along with the power requirements of all the components.

What has been proven is that that the can and do work in Carrier given half a chance.

They come in many sizes and configurations. Like IC engines: How deep are your pockets? Mine are shallow, so budget is what I look for. More blades are more efficient and less noisy.  Beyond that it's suck it and see what happens. If you go down the RTF model conversion route, the problem is almost solved for you, it should work out of the box. You may have to increase the cell count to get the maximum out of the model; if it, and the battery will fit, and the ESC and motor can cope.

Batteries

A LiPo battery of sufficient capacity to fly a single contest flight is ideal, as you will not be carrying around and extra weight. Comming from RC flying you may be surprised how small a battery you actually need. Ending with between 10-20% charge is good. This will mean, either more than one battery being available, or charging between flights. either is  preferable to doubling the weight of a battery.

Number of of cells depends on the motors KV rating, what the ESC can handle, size and pitch of the prop. The motor manufacturer will usually have all this information to use as a starting point.

Taking 4 cells as starting point is sweet spot. Many Basic and Junior Class models will still fly well on 3 cells, only missing or on the fast run; but as the scoring is biased towards slow speeds, this is not as bad as you might think. Unfortunately a bit of suck it and see is needed until you can work out the best combination of battery, drivetrain and model is reached. Good quality batteries help a lot but tend toward being expensive. If beginning there is no harm in using cheap 3 cell batteries to cut your teeth on. Not literally of course, that would be a very unwise thing to do, causing a bit more surprise than licking small  9v battery terminals.

Internal Combustion, Glow (AKA Nitro):

Well known and understood, engine capacities range fro 2.5cc (0.15cu in) for Junior Class up to 6.5cc (0.40cu in). Many engines around 5cc (0.30) size can have a very high output these days. IC engines are the go to if you are lucky enough to have access to a noise tolerant site to fly from. If you like oily fingers and anything that goes, suck, bang, blow, also  don't mind spending time finding a fuel system that is reliable, along with a fuel that will give the best performance, These engines are for you. 

For beginners there are many cheap non-racing engines that are quite capable of winning comps; reliability plays a significant role.

Fuels tend to have 5 to 10% Nitro content, Over 10% tends to follow the law of diminishing returns.

What sort of fuel and glowplugs?

Fuel doesn’t necessarily need to be anything special at all. Basic Carrier Deck is not a horsepower event. It’s much more important to have an engine that starts easily, throttles well, doesn’t blow plugs and lasts a long time! Use of nitromethane in the fuel has the advantage that needle valve settings are generally less critical, but high nitro percentages require lower compression ratios (usually involving cylinder head shimming) and can burn out plugs. Unless your engine is designed to run on high nitro contents, 5% or 10% of this power ingredient is usually enough. Some engines even specify straight fuel, ie: a plain methanol/oil mix.

Plugs, too, are not a major issue. Most engines used in BCD will behave well on a variety of types. However, low throttle periods can be extended during the slow run and in a very few cases the engine can become over-cooled and the fire can simply go out. The solution here is often a barred plug (usually called an R/C plug), or a plug that’s a hotter grade. Plug grades are measured by a number which increases with the hotness of the plug. Hotter plugs produce better idling but have an increased risk of burning out.

Carburettors

Setting them up is a  common problem that must cost more wasted time and frustration than any other. So here lifted strait form my old website in 2007 is a guide. with some additional notes to bring things up to date  Zoe Quilter

The Six Steps To Happiness

Or how to set up a carb from scratch

Although not part of the carb setting sequence, it is important to get this part right first.

With the throttle open and the main needle set to just under peak revs, if the revs drop, or the engine cuts when the glow clip is removed, change to a hotter grade of plug. Failure to get this right will lead to false conclusions when trying to set the carb.

The following steps require patience and can be tedious, but once set the carb should stay that way, and only occasionaly need some fine tuning. I also suggest you do not try setting up a carb on a new engine until it has had a least 30 minutes running, preferably in a test stand.

Please try to get into the habit of making adjustments standing somewhere behind the prop arc. That way if something goes wrong or the prop sheds a blade you will be in safest place. Maybe not any spectators, when you swear at the pain and let go of the model, but you at least, will be. Even I don't always do this, but if I get hurt, then I know it's my own stupid fault. Any remarks in red, I think are important; far more important than the, "Don't start the engine by flicking the prop by hand under any circumstances." advice printed on every instruction sheet these days; which is BS, and should read, "Don't stupidly put you hand through the prop arch when the engine is running." The last is much less likely to happen if you do what is printed in on the first line of this paragraph in Red

I will add that there are adapter kits kits available the allow the main needle assembly to be mounted on the engine backplate. This is far safer and easier to use than the normal set up and well worth fitting or fashioning yourself. Whilst I was still using IC engines I converted every one I could, it has no effect on performance, but  no more fingers being clipped by the back of the prop.

One last point before we begin. If you have a pressure feed connected to the tank when going through this sequence, you must set up with it connected, and working properly, or you will have to go through the whole sequence again.

(1) ALWAYS adjust the main needle with the throttle wide open for peak revs, if the carb has a mid range adjustment screw it right  in to block any flow first. Once the engine is at peak revs unscrew the main needle a small amount so the revs drop very slightly. This is to make sure the engine is not running in a borderline lean condition which could do damage.

(1a) Now hold the model vertically nose up with the throttle wide open for slow count of 10, adjust if necessary to keep it running. This may mean it runs slightly slower in horizontal position. This OK as long as it's only a slight change  if it's big change you have fuel feed problems that needs sorting out before doing anything else.

DO NOT ADJUST THE FAST RUNNING MAIN NEEDLE FROM NOW ON. IT IS SET AND SHOULD STAY THAT WAY. It should only need very minor adjustment in the future after everything else is set up ( I mean +- 1 or 2 clicks if its spring loaded, or a couple of degrees, not half a turn, AND NEVER when messing with, or setting up the slow running; this will lead to madness and falling down a deep hole you can't crawl out of.

If the engine will not run like this, there is something seriously wrong, and nothing to do with carb. If the engine, WILL, start and run like this, then it is in good health mechanically and the basic fuel plumbing is working. Worn engines (bad piston seal etc.) will not start readily by flicking, especially when hot; something that an electric starter will disguise. Flicking has always been my favourite way to starting an engine, it can tell you more about it's state of readiness or wear in few seconds, and is not dangerous if done sensibly. Ramming a starter at a recalcitrant engine will disguise and hide many things, which may not be of consequence for sport flying, but could let you down at the worst moment in a competition.

Note:  I have added the following section due to changes in practice and manufacturing since I first wrote this piece.

The next part needs to be ascertained before trying anything else. 

Carbs tend to have two basic means of determining how much the the throttle remains open when fully closed. Older ones have a Stop Screw which physically stops the choke barrel from closing completely; these I always preferred over next type, because of simplicity and reliability.

Due to the prevalence of RC influence. many carbs now have nothing to stop the carb barrel closing completely, relying instead on a servo trim to set it. This can complicate things if using a three line system; but it's not difficult to makes a substitute mechanical stop.

However with the use  of modern hand held radio equipment being used these days, it seems to raise some issues and common mistakes that I have observed people make repeatedly; apart from making what should be simple setting more difficult.

The process I suggest  is with the model horizontal and AFTER step (1) is set up properly. Start slowly reducing the throttle until the motor stops , Now set your trim to the point where it just keeps running. It does not matter if this considerably faster than you expect. you now have a baseline to start from.

DO NOT ADJUST THE FAST RUNNING NEEDLE

Older carbs had an air bleed screw to adjust the slow running, less air leaner mixture:  more air richer mixture. Modern carbs use a metered  fuel bleed system more fuel richer mixture less fuel leaner mixture that can also affect the whole of the throttle range up to full throttle sometimes referred to as a midrange needle, as the latter are more common. That is what I am referring too from now on. 

I'm inclined to think this where people come unstuck when trying to set a carb. Because there is interaction between the throttle opening and the amount of bleed that is introduced over the full range. it's easy to be mislead into thinking  that at fully open if things appear to be too rich the main needle is to blame, when in fact it's the mid range adjustment. If you set the wide open setting first with the main needle; it IS correct already.

If you have fully closed the need range needle as I suggested at the beginning it will stop at some point. The  mid range setting will be too lean; open it up 1/4 turn and repeat until you can reduce the speed to a suitable tickover. This will take time and repetition don't rush it. If the engine sounds lumpy and smokey before it stops close the midrange needle  by 1/4 turn and repeat.

Once you have reached a  clean consistent  tickover, follow these steps.

Back the the original text

DO NOT BE TEMPTED TO ADJUST THE FAST RUNNING NEEDLE

(2) Close the throttle, tick over for ten seconds, open the throttle to full

(3) if the engine dies, unscrew the midrange needle 1/4 turn and repeat from (2).

For safety's sake, stop the engine each time, before adjusting the mid range jet. Some have very fiddly small screws and it will only take one careless move or slip to do a lot of damage to yourself. So please, use some common sense.

(4) If the engine splutters then picks up, screw the midrange needle in 1/4 turn and repeat from (2).

(5) Aim for a clean pickup from tickover when the throttle is opened quickly to full throttle.

When close to the desired settings reduce the midrange needle turns to 1/8 of a turn at a time to fine tune.

(6) In a dire situation where nothing seems to work, try unscrewing the mid range needle out as far as it will go, then start afresh from (1)

And most importantly. Ignore all the rumours you have heard about engine/carb X,Y, or Z, being  the best, and even the club expert that leans over your shoulder and says, "Try this."there  is  nothing worse as you try to methodically work to a conclusion, such advice can throw you right off.

 Work through this list first; I will be very surprised if you don't have some success.

Now you know as much about setting carb's as I do.