View Full Version : BEGINNERS ANSWERS and ADVANCE TIPS covering various topics
PROPS EXPLAINED
Props are described using two numbers seperated by an "x".
The first number is the diameter of the prop...how many inches long the prop is. The second number is pitch in degree's..or the distance the prop would move FORWARD if turned 1 complete time and there was no air slippage.
Sounds confusing doesnt it...well it only sounds confusing. Lets look at a 10x7 prop for example.
The prop is 10 inches in diameter and if turned 1 complete turn would pull the plane forward 7 inches!! (remember the moving forward 7 inches is fantasy land since we are not taking into account air slippage)
Now, there are several terms that are specific to props to help us distinguish between their intended usage.
E= Electric
SF= Slow Fly
P= Pusher
These letters usually appear after the prop numbers so a "slow fly" prop would read 11x3.8SF.
A simple way to look at prop and prop number is this:
Diameter effects THRUST, increase diameter and thrust increases. Pitch effects TOP SPEED, more pitch faster flight at WOT.
Changing props can improve or destroy your planes performance. Its important to know what the motors limits are. Changes in Diameter have a small effect on amp pull, but changes in pitch can have a significant effect on amp pull!!
There is always a trade off between thrust and speed. The key is to find the prop that fits your style, stays under the motors max amp pull, and doesnt strike the ground during take off or landing!!
3 Bladed props
Now if your not confused enough....
switching from a 2-bladed prop to a 3-bladed prop requires a very simple rule of thumb... reduce diameter 1 or 2 inches and increase pitch by 1 or 2 inches.
But please remember, a WATT METER is your friend. Always check your power system after changing props or when you first put all the pieces together. Losing a plane because you over amped the motor or ESC by installing too much prop makes Johnny a very sad boy...and you the target of the "professional RC pilot hecklers"!!
POWER REQUIREMENTS
We use WATTS as a way of deciding how a motor will perform and as a way of deciding how a plane will fly on that motor.
I highly recommend that anyone in this hobby get a watt meter. EFlite makes one, Watts-Up has one, and I think several other companies make them as well. You HAVE to know what your system is doing or you risk damage, fire, or injury!!
The following chart is a basic idea of what you should be looking for when you assemble your own power systems.
Slow Flyer: 60-75 watts per lbs
Park Flyer: 75-100 watts per lbs
Acrobatic Sport Flyer: 90-125 watts per lbs
3D Flyer: 150-175 watts per lbs
Now its important to know what your AUW is going to be on the plane so you can do the quick math to figure out how much power your motor needs to produce to get the results you want.
So If you plane weights 2lbs AUW and you want to do 3d you would need at least 300 watts....now in my case cause I like to have a little "turbo charged reserve" would aim for 325 watts or more.
Now by all means this is MY guide line... I prefer to over power my planes...thier like sports cars, they can never have too much power!!
ESC's
Electric Speed Controllers or ESC's are what regulates the power the motor and come rated at their max amps. In many cases they also have a built in BEC (battery eliminator circuit) that provides power to the RX and servos thus reducing the need to a seperate RX battery. You will want to get ESC's that have a 5 amp BEC if your running 4 or more servos, most smaller ESC's only have a 3amp BEC. In some cases its best to buy a seperate BEC like the CC 10amp BEC, especially for larger planes that are using 5 servos or more.
All ESC's come with various options or "features". I am only going to address a few as by the time you get past these features and really start "tweaking" your ESC's you will already know everything you need to know about ESC's!!
1) LVC- some have a present 70% of starting voltage...thats BAD!! Mistakenly use a partial charged lipo and you can kill it!! Ensure your ESC has a set voltage cut off based on the number of cells. Some ESC's have auto-dection and they beep the number of cells they see. Other can be programed via the include instructions to set the LVC. Always set the LVC for the number of cells you are using.
2) Start types - Soft/medium/hard, I always prefer soft or medium. Soft is important with gearboxes. A hard start increases the chances of damage to the teeth.
3) Brake - Its either on or off... in most cases you want the brake turned OFF... in the case of a folding prop then you want it on.
4) Voltage- some allow you to set the voltage that is used to support the RX and servos. In most cases the "stock" setting is 4.9 volts but can be increased to 6 volts. With most servos increasing the voltage will increase their speed and tq. Plus I like the extra voltage to help prevent "brown outs" that can sometimes happen with Spektrum RX's.
The most important thing to do before all else is find out what the max amp pull for your motor is...then pick an ESC that is a few amps over that for insurance reasons. Some ESC's literially will go up in smoke if you hit the number they are rated for, others can handle 5 amps over their rating...only time and experience will teach you which ones can handle more so always error on the side of caution.
ESC's DO NOT determine how many amps your motor pulls!! Amp pull is determined by prop size and voltage. (a motor running a 10x7 prop will pull less amps on a 2s lipo then a 3s lipo. If you need to sadjust amps on a specific set up (motor and lipo are staying the same, you can adjust the amp pull by changing props to either increase amps or reduce amps)
Too much ESC is a weight penality, too little ESC is a crashed plane.
PAINTING FOAM
There are several ways to prep the foam. This is how I do it:
1) take light weight spackle on a old credit card or video store card (hallmark calander, etc) and lightly wet it with water.
2) carefully smear/spread the spackle over the foam, carefully working the spackle into any holes/dents
3) allow it to dry completely
4) using 320 grit sandpaper carefully sand the foam DO NOT USE A LOT OF PRESSURE or you will damage the foam
5) carefully wipe the foam down.
6) repeat steps 1 through 5 till smooth
7) Now to seal the foam and spackle. Using water based Polycrylic apply a light coat over the enitre plane.
8 ) Lightly sand with 320 grit sandpaper. It should turn a little hazey looking. Any spots that are shinny are low spots.
9) carefully continue to sand till the shinny spots disappear or you hit bare foam again.
10) Apply another coat of polycrylic and allow to dry
11) Lightly sand again using 320 grit sandpaper till the plane is a little hazey (tip the plane on its side and looking along the surface will help you see some of the shiney spots.
12) Repeat steps 10 to 12 till you are satisfied with the smoothness of the surface.
Now you are ready to paint
I recommend WATER based paints as they wont eat the foam. Testers in the rattle can works also but stay back 12 inches as the propellent will eat the foam.
I prefer to airbrush my planes. I use Apple Barrel paints from Wally World as they have a good choice of colors, are cheap, and they are water based. I use Windex to thin the paints for the airbrush as the Windex evaporates quickly allowing the paint to dry rapidly. Use light coats and allow each coat to dry about 10 minutes in between coats.
Once dry, you can cover it with a light coat of Testers Matte finish as this will protect the colors from water and light wear.
STRIPES/SHAPES/PATTERNS
To do stripes or patterns you can either use painters tape or you can use cardboard and cut shapes out of them and use them as a stencil.
PROTECTING BELLY FLOOPERS
On belly floppers, I like to apply 2 light coats of WPBU as it will form a light "plastic" coat that will help protect the bottom from grass rash!!
CAMO PATTERNS:
If you looking to do a camo pattern for a WWII bird or later era fighter this little trick works great (check my hange picts for the P-40 as I used it there)
1) paint the plane the lightest color
2) once dry, tear strips of newspaper into various shapes, wet them and lay them over the plane. Dab up any stray water thats on the paint.
3) Paint the second color, allow to dry for 5 minutes and then CAREFULLY remove the newspaper without letting it drag or touch the newly painted plane.
4) If you are going with a 3 color scheme go back to step 2 after the paint drys and repeat steps 2 and 3.
5) Once done, let it all dry and then coat with a matte finish.
HIGH VISABILITY SCHEMES:
I like to use RED and WHITE on high visability aircraft. Red or White DIAMONDS across the bottom of the wings stand out nicely in the air, stripes on the top of the wings will stand out as well and help you distinguish top from bottom. Make them LARGE, thin stripes or small diamonds will disappear at a distance so all that work will be for nothing!!Others like WHITE and HUNTER ORANGE or RED and YELLOW.
WARNING:
Grey, Black, or Dark Blue planes look cool on the ground but in the air at a distance they are anything but enjoyable. The colors cause the details to disappear, leaving you guessing if the planes tilted since the wing now completely disappears against the fuselage. I highly recommend that only experienced pilots paint their planes any of those colors as you have to instinctively know what your planes doing at all times.
EXAMPLE OF FOAM BEFORE AND AFTER PREP:
http://www.horizonrcflyers.com/forums/attachment.php?attachmentid=3392
LIPOS:
Lipos, yes, the battery of choice for performance and weight savings...
Sounds good doesnt it?? It is good, but like all good things there is a catch....lipos if mis-treated can cause fires!! No, not those little fires you cook marshmellows over either but rather the type that leaves you living out of your car or the local flea infested hotel!!
SPECIAL CONCERNS:
1 ) NEVER charge a lipo unattended
2 ) NEVER over discharge a lipo
3 ) NEVER over charge a lipo (never charge faster then 1C)
4 ) NEVER store below 50*
5 ) NEVER leave in direct sunlight
6 ) NEVER leave near a heat source or flame
7 ) NEVER puncture your lipos
8 ) ALWAYS charge with a lipo specific charger
8 ) BALANCE often!
FINDING A LIPO:
Ok, so you need a lipo and the for sale forum has this listed as NIB:
20c 3s 2200
.... does that make sense to you? What kinda monkey scribble is that?? I just want to fly my plane!! No worries, it will make sense when we are done and its odd aray of numbers and letters will instantly become translated in your brain when ever you see them later, even when all the numbers change!!
Lipo Basics
Cells:
Lipos are made up of "cells". Each cell is 3.6 volts nominal (4.2 volts full charged, fresh off the charger). Cells are connected and packaged into "packs" to create various voltages and mahs.
1s = 3.6volts
2s = 7.2volts
3s = 10.8volts (this is the most common for parkflyers)
4s = 14.4 volts
etc
Note that a letter "S" is used to signify "cell"
MAH:
"Mah" is miliamp hours...or the easiest way to think of it...its the size of the fuel tank. The more MAH, the longer your flight times...or the more amps you can discharge from the lipo in a hour without killing it. But we'll cover the other factors that determine the max amp pull later.
C RATING:
C ratings tell you how hard you can push the lipo before it releases the magical white fairy and turns into a fireball...actually they usually swell up and then catch fire. (Think of the movie "Big Trouble in Little China"....remember the guy in the end that just keeps expanding till he pops?? Lipos do that if mistreated!!).
READING LIPO INFO:
So the above monkey scribble of 20c 3s 2200 is read like this:
20c discharge rated, 10.7volt, 2200 mah lipo
Now the question is will it support your motors amp requirement??
MAX AMP DISCHARGE
Ok, so how do you take all the numbers and figure out if the lipo fits your needs? Its simple, just do the math!! hey get back here!! I know its not school but the math really is simly... remember if monkeys did the scribbling, you can do the math.
So here's the equation:
C rating * MAH = max amps
so taking the monkey scribbling from up top we get this:
20c * 2200mah = 44 amps
So the max amps that lipo can pull before it turns into a mini-sun and leaves you homeless is 44 amps. The number of cells has nothing to do with how many amps it can feed your motor. The number of cells determine the voltage which directly effects the motors RPM's (remember the equation for RPMs?? KV*V=RPM).
Where this is key is that if your motor's max amp pull is over 40 amps, this lipo isnt going to work for you unless you prop down (see prop post).
You need to ensure your lipo can feed enough amps to support the motors amp pull. A lipo that can feed your motor 60amps and you only need 20amps is not a big deal...actually thats sorta a good thing. The lipo wont get worked hard so you should get lots of flights on it. Its when you over work your lipo that you have issues.
As a rule of thumb, the higher the C rating the better as you can always work the lipo less with no ill effects, but work the lipo beyond its C rating and you are going to become very unhappy!!
MOTOR THRUST LINE
This is a topic that every pilot needs to understand. This can make or break how well a plane handles.
The motor thrust line is designed to do two things:
1) reduce the effects of the torque generated by the spinning prop
2) apply a little downward force to the plane.
A prop spinning in one direction will cause the PLANE to try and spin the opposite direction. Which means at low speeds if you punch the throttle the plane will do an uncommanded roll!! The basic rule of thumb is 3* right thrust on a prop that clockwise if your standing BEHIND the plane looking from the tail to the nose. By pointing the motor off to the right a little the torque isn't in a straight line with the plane so it would require more torque to effectively roll the plane.
Think of the motor as a screw driver and the plane a 3" deck screw in a wall. If you have the screw drive aimed straight into the top of the screw you can easily back the screw out...but if you angle the screw driver handle out 1/2" to the side and try backing that same screw out it becomes extremely difficult!!
Planes that are hand launched tend to be hand launched at 1/2 throttle and once they get on step (up to stall speed) throttle is slowly applied. If you were to jam the throttle before getting "on step" you could actually induce a torque roll and plant your plane!! The right thrust is to help the lift generated by the air over the wings to overcome the motors torque.
Now, why the heck would you want to apply down force to your plane?? I thought the whole point of planes was to make them go up!! If I wanted it to stay on the ground I would have bought a RC car and played in the street in front of my house driving the old lady next door crazy chasing her stupid cat around!! I want to torment that stupid bird of hers!!
Wanting to add down force to a plane does sound crazy but when you look at the entire plane and what the parts do and how things interact with their environment you will understand that without some down thrust on the motor giving you some down force you'd only have a RC loop maker!!
An airplanes wings are designed to create lift as the air moves over them...the faster the air moves over the wings, the more lift they create.
The more lift they create the faster the NOSE of the plane rises up!!! So now your riding the elevator trying to keep your nose down and the plane is still trying to climb!! So you roll the throttle back to 1/2 stick and trim her for level flight...all is good once again....till you hit the throttle and the nose shots up like a home sick angle!! But I dont understand why? She was trimmed at 1/2 throttle... hence your problem is a lack of motor down thrust!!
By building in a little down thrust on the motor it pulls the plane just slightly down countering some of the planes lift. This allows the plane to be trimmed at 1/2 throttle and not have SEVERE changes in pitch with changes in throttle.
Without it this is what the throttle stick would do with the plane trimmed for level flight at 1/2 stick:
Stick position planes response
throttle off - plane would nose dive
1/2 stick - fly level
WOT - plane would go nose up
Man, flying that plane would suck, not to mention none of us would have stayed in the hobby long.
The point being that with the correct motor thrust line you should be able to trim your plane at 1/2 throttle to fly level and from there any change in throttle position should cause a slight, gradual change in the planes pitch. It should not look like Space Shuttle heading to space nor should it look like Michael Vicks football career after the dog fighting ring!!
Remember the basic rule of thumb is 3* right and 3* down...if you have your CG set correctly, plane trimmed correctly and your still experiencing significant pitch changes when applying or removing throttle then you may need to adjust your thrust line. I find that small washers placed between the firewall and motor mount work great for adding a degree or two of down thrust or right thrust!!
The larger a prop is the more torque it can produce at the same RPM compared to a smaller prop...so by stuffing a larger, faster motor into a plane then what the company recommends and then sticking that big prop on there so you can take off in 2 feet instead of 30 feet is probably going to require a change in thrust line. Just some food for thought....
EPOXY
Epoxy is listed in working time... 5 minute epoxy can be applied for about 5 minutes (temp/humidity will have some effect on the time).
The longer the epoxy time, the less brittel the epoxy joint is, meaning it will take more stress before breaking!!
The epoxy that I know of (the most common) are:
5 Minute
6 Minute
10 Minute
15 Minute
30 Minute
60 Minute
I personally use 5, 6, and 15 minute epoxy.
Its important to prep the surfaces for epoxying. I lightly sand both surfaces. With plastics you need to rough them up so the epoxy will hold.
Use wax paper under the two surfaces as any epoxy drips will clean up easy and in the eevent that you mistakenly epoxied the parts to the table (or inthis case the wax paper) you can still move them and the wax paper is eaier to remove then the kitchen table!! (please dont ask how I know, I was a newbie once too... LOL)
Heres a little tip your LHS will hate... I use Q-tips to apply and mix my epoxy. I mix my epoxy on paper plates and cut the cotton tip off the Q-tips. I then use the Q-tip stick to apply the epoxy and then lightly SCRAPE the excess epoxy off the parts... you dont need a lot to secure the pieces together and any excess you leave is just added weight!!
Another little tip is mix sticks...you know the $4 bag of flat popsicle sticks for mixing epoxy or paint. We you can find them at the dollar store near the pens and paper for $1 (qty 100!!). Needless to say you can beat that price.
TOOLS OF THE TRADE
Here is a list of the tools every RC hobbiest needs to have in their box. Whether its for building the planes or repairing the planes having the correct tool makes a huge difference.
1) Soldering Iron
2) 3d Hand (aligator clip support)
3) WATT METER
4) Jeweliers screw drivers
5) Needle nose pliers
6) Regular pliers
7) Surgical pliers (silver, long, thin and locking!!)
8 )Heat shrink
9) Hex drivers (small)
10) Xacto knife (w/extra blades)
11) Packing tape
12) glass cloth (used with epoxy you can fix anything)
A few things I like to keep on hand as a precaution are:
1) 2 extra servos
2) Extra CF rod
3) CA (foam safe; Regular (thin and medium)
4) Epoxy
5) extra ESC (usually 40amp as that fits most of my planes)
6) extra props
7) extra set of LG.
8 ) 6" servo extension
9) 6" Servo Y harness
You never know when your going to break something and its always something small, stupid, and inexpensive...because its the 1 item you dont have in your box because its easy to overlook.
TIP: Never throw anything away... save every screw, washer, connector, piece of wire, etc... its amazing how often you will hit a spot where you can use it to keep flying!!
CENTER OF GRAVITY
CoG is very important. Every plane has specific range in which the plane will fly/handle well.
Basic rule of thumb is:
-Slightly nose heavy is good
-Tail heavy flys once...and gets taken home in a bag
Nose Heavy- Slighly nose heavy makes a planbe stable..too nose heavy and into the ground she goes.
Tail Heavy- Tail heavy and the plane will stand on its tail with some speed and stall out. Also the plane will be very pitch sensitive so the elevator will be very touchy!! This is why tail heavy planes tend to only fly once.
So how do you balance the plane. I use my finger tips. I measure and mark the CG as listed in the planes instructions. I then add the lipo (or what ever battery I am using). I then plane my fingers on the marks and look to see what the plane is doing.
I want the nose to be slightly lower then the tail... maybe 2-3 degrees lower. This is a great starting point for maidens.
Now you need to fine tune the CG in the air. Get her trimmed out for 1/2 throttle and roll her inverted...she should need just a little down elevator to stay level (remember your inverted so down is up).
If your plane's instructions do not provide a CoG dimension of if you'd like to figure it for yourself here is a link to CoG calculator, http://adamone.rchomepage.com/cg_calc.htm , easy to use and quite accurate.
Custom Graphics
We all have airplanes thats markings have slowly cracked or been damaged during a crash that we were unable to save during the repair process or want to add detail. I highly recommend Callie-Graphics as she does awesome work and has great prices.
http://www.callie-graphics.com/
FIELD BOX
I have 3 boxes I take with me when ever I fly: the first carries my TX's, the second carries my lipos, and the third is my "crap I need to fix/replace that before I fly" box. The worst feeling in the world is being at the field and not being able to fly your plane because something either came loose, broke, or you forgot to install it. A "field box" can prevent 90% of the issues from being a real issue and in my case I refer to it as my build box as well since most items needed to build a plane are located in the box. All my other building tools stay in another box in the garage next to the build table.
What I carry in my field box:
1) extra props for all my planes
2) CA (thin regular, regular, thick, foam safe)
3) "Kicker"
4) extra servo
5) servo wire extension
6) set of small screw drivers
7) pliers
8 ) scissors
9) needle nose pliers
10) tape (packaging)
11) Colored electrical tape (great for adding quick color stripes to aid in orientation)
12) Xacto knife
13) Hex drives in the common sizes
14) Double sided tape
15) Binding plug (for the Spectrum RX's)
16) Velcro (hook and loop)
17) Extra prop adaptors
18 ) Loctite
Items I dont carry but a flying buddy carries:
19) 6 minute epoxy
20) mix cups an dstir sticks for the epoxy
21) Soldering Iron and solder
22) Wheel collars
FOR GAS/GLOW PILOTS, RCDude07 recommends the following additions:
23) Extra Glow Plugs
24) Glow Starter or two
25) Lock-Tite (good for all flyers)
26) Engine starter and battery source
27) Chicken Stick
28 ) 1 gallon of fuel (more depending on how long plan to be at the field)
29) TX Neck Strap
30) Fuel overflow Catch can (just an extra fuel tank)
31) Cleaner and rag for cleaning the slime off at the end of the day
32) Tachometer
Here is a picture of a nitro field box that is used by RCDude.
http://www.horizonrcflyers.com/forums/attachment.php?attachmentid=5159
With these items at the field you can fix nearly any plane and get back in the air quicky without a trip home. They cover all the common issues, stripped servo, broken prop, cracked wing/fuse, orientation issues, loose ESC/RX bouncing in the fuse.
I would like to thank RCDude07 for his help with gas/glow requirements as I am only experienced in the realm of electric flight and I often feel like I am short changing the gas/glow flyers of valuable information.
WING LOADING:
Wing loading is an important number. It is the AUW of the plane divided by the wings area. It will provide you with a basic idea of how slow a plane can be flown before it stalls. The lower the wing loading, the slower the plane can be flown. Higher wing loaded planes handle the wind better but will require a faster landing speed.
To figure wing loading take the AUW in ounces and divide this by the wing area. To achieve wing area take the mfr's square inches of wing surface and divide by 1' squared. The answer will be how may square feet surface area your wing has. Take the weight of the plane, again fully ready battery in plane (AUW), and divide the weight by the square foot of wing surface area. For examples:
The E-Flite Apprentice weighs in at 45 ounces and has a wing surface area of 525 Sq. In. Take 525 divide it by 144 (1 foot squared) and you get 3.64. Take the weight 45 ounces and divide by 3.64 and you end up with a wing loading of 12.36 oz. per sq. foot.
Contrast that with the E-Flite Deuces Wild which weighs in at 168 ounces and has a wing surface area of 740Sq. In. So again 740 divided by 144 equals 5.13. Take the weight of 168 ounces and divide by 5.13 and you get a wing loading of 32.75 Ounces per Sq.foot of wing loading.
Giving definition to these numbers of wing loading,
10 Ounce or less per sq foot wing loaded planes are gentle flying airplanes that can be flown very slowly. Float around easily but usually are easy to be blown off course and can be difficult to fly on anything but calm days. Landings are slow but easily effected by cross winds.
11-20 Ounce per sq foot wing loaded planes are the next step into a trainer plane that offers some faster landings and can be flown in light to moderate winds up to 6-8mphmph. Landings are more controllable and the plane is not pushed off course as easily. These planes are targetted at beginner pilots readying for the step to intermediate aircraft.
20-25 Ounce per sq foot wing loaded plane start becoming more thrust hungry and generally do not fly as stable at lower speeds. The planes are usually more powerful than their lighter cousins but can still be landed and taken off without the aid of flaps. This is an intermediate pilot's airplane.
Above 25 ounce pr sq foot wing loaded planes are usually military and aerobatic scale planes. These planes land and takeoff much faster and use the aid of flaps to slow landings or decrease takeoff runway lengths. To contrast this to the 10-15 ounce per sq foot planes these planes will not fly very long distances without a form of propulsion as the wing's lifting ability is far less. These planes are for intermediate and advanced pilots.
Keeping a plane as light as possible is a key habit to get into when picking out parts for your planes. Yes, a bigger motor will give more power but will also require a larger lipo and that means more weight. You can make a brick fly but it wont be much fun to fly and even less fun to try and land.
WJCJR1
03-17-2010, 05:55 AM
TESTING and TUNING:
Testing and Tuning is a crucial part of refitting a plane to your needs or goals in flight character. As ATIS described above props have two sides of output, thrust and speed. When tuning your plane to the desired levels of either thrust or speed or both you will inevitably be changing props, motors, batteries and possibly ESC's. Whenever a new power system is employed it is vital a full power system analysis is completed. This analysis should be performed even on factory setups as well including RTF airplanes, a baseline power measurement is helpful in troubleshooting potential problems with motor, ESC or battery for damage, wear or future performance tuning.
The common tool used to perform a power system analysis is a Watts, Volts, Amp and Capacity meter. A couple examples of versions of this are such as the E-Flite brand; http://secure.hobbyzone.com/catalog/HZ/search/EFLA110.html or the more household and more user friendly, in my opinion, WATTS UP meter; http://www3.towerhobbies.com/cgi-bin/WTI0001P?I=LXLMV0&P=8 By simply placing this device inline (between your battery and ESC) you can measure all major components of power draw.
Applying the terms, knowledge and tutelage ATIS provided on Props, Motors, Batteries and Electronic Speed Controllers you can now use your meter to accurately adjust the power curve of your props and motor. Manufacturers provide several parameters on motors, ESC's and batteries that are critical and relative to each other they are;
Continuous Current; this is 'speed limit' of continuous amperage. This limit is the 100% duty cycle limit at which said motor, battery or ESC can be safely run at all the time.
Burst Current; this is the absolute highest peak AMP allowable and usually there is a time marker designated for this AMP readout such as (15sec). Exceeding this current level or time of burst duration can permanently damage your motor, battery or ESC.
Voltage Range; this is the input voltage range of component being used. This ties in directly to the LIPO being used, 2S= 8.4V, 3S=12.6V, 4S=16.8V.
These common parameters are related to each other and the manufacturer specifications must be followed closely otherwise damage will result.
First part of testing/tuning is deciding which motor you will start with. This choice can be easily made by following the motor manufacturer's aircraft intended design flight characteristics. Most manufacturers will give you a listing of motor intended design flight character such as the following hypothetical example; Wayne's motor is designed to deliver clean and quiet power for 30 to 36 size sport and scale airplanes weighing 3.5 to 6 pounds OR 25 to 36 size 3D airplanes up to 4.5 pounds. With this desription if you were running this motor in a 7 pound scale plane the plane would be underpowered, conversely if you were using this motor in a 3.5 pound scale plane you would have ample power to enjoy.
So let's say Wayne's motor is identified as your choice of motors as it fits the general need for your size plane; the above mentioned/bolded parameters would be supplied from the manufacturer. For this example motor I know the following from the manufacturer;
Continuous Current: 42A
Burst Current: 60A (15sec)
Voltage Range: 12-16.8 (3S-4S LIPO)
Suggested Prop Range: 11X7-14X10
With these manufacturer ratings you are aware you need an ESC and Battery capable of handling a 60A draw. Do you need to use all that power, NO, but plan for it. Using ATIS's teaching of motor kV and prop character we understand that more pitch and more diameter means more current draw. Since Voltage is directly related to motor RPM if you were using a 4S battery you certainly could not turn a 14X10 prop without amping out. This suggested prop would be on a 3S battery as the voltage being lower turns the prop slower and less draw.
When setting up your plane you now need to decide what do you want: Speed, Thrust, some combination thereof. More speed means more pitch needed. Too much pitch and not enough diameter leads to a slow climbing plane that stalls out quickly but can reach greater speeds. Too little speed and a Heavy wing loaded plane may be tough to handle as the lift generated by airspeed is lacking. As you can see going one way or another too much serves very little purpose, hence you are likely to end up with a compromise leaning in one direction a little bit but not over the top and sacrificing too much.
Now to TESTING: After you have set your plane up with your chosen motor with the correct sized ESC and battery capable of delivering the motor's burst current and purchased a small sampling of different props to fit your needs you are finally ready to test. To perform your power system test clear the area arond your plane, turn on your TX, plug your WATTS UP meter (or equivalant) into your ESC connector then plug your battery into your meter. All you are doing is putting your meter in line between your battery and the plane, you are going to measure the flow of power from the battery to the plane. Now whle holding firmly onto the planes fuselage and staying clear of the prop slowly bring the motor to WOT, I pause 5 seconds, then slowly lower the RPMS to a stop. That's it your done testing that prop, painless and will save you $$$$ and aggravation.
Reading the RESULTS: Disconnect the WattsUp meter from the ESC, but LEAVE connected to the battery. Not all meters are as nice as the WATTS UP as this meter saves the peak and minimum readings on a scrolling LCD sceen and others you have to read while you are bring buffetted by prop wash. I think the reading while testing should only be use to assure you do not over amp but closely looking to read all data is unsafe at best. So the WATTS Up although costing a few dolllars more is well worth it. Now to read the WATTS Up scrolling on the LCD you will see:
RealTime Live Voltage and Amp Readings
Ap(Amps Peak) The highest AMP reading recorded during the testing session.
Wp(Watts Peak) The highest Watt reading recorded during the tesing session.
Vm(Volts minimum) The lowest Voltage sag reading recorded during load test.
Ah(Amp Hours) The amount of electricity used during the testing session.
Then when analyzing the data the biggest numbers will be Watts and Amps. Watching out for your plane's equipment is critical in making sure you DO NOT EXCEED any of the power system component's limits. As with the subject motor above and assuming all other equipment was purchased properly as long as I stayed below 42A continuous and 60A Burst I am good. This does not mean this is the best prop for my plane but it does mean it is ok for me to use and not destroy the motor, ESC or battery. About burst, to clarify, let's say 3 clicks below WOT I was pulling 42A in the test and at WOT I pulled 50A. I could assume then that I can run my motor all the time a 3 clicks below WOT and be safe and when exceeding that 3 clicks area (considered burst mode since I am exceeding the 42A continuous) I could only do for 15sec at a time as determined by the manufacturer's rating. Burst mode must be used sparingly with plenty of cooling inbetween.
Test fly your aircraft see how you like the prop and setup, TEST TEST TEST until you find the best prop for whichever circumstance or scenario you wish to fly. I have found mostly manufacturers recommend a set up that is tried, true and provides the middle of the road compromise in performance between thrust, speed and flight duration.
This Power System testing should also be performed on EVERY new model you have especially when it is fresh from the box. By getting a baseline measurement you can troubleshoot or detect wear in your power system since you have a good solid baseline to compare against. If you own electric planes you need a power system meter, familiarize yourself, learn/understand how to use it, this is a simple tool that can save your airplane and make the hobby of R/C Aircraft a lot more enjoyable.
Wayne
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