All this info...

[frvrngn]

Hopefully the motor stuff helps out some people. That is all info that I have gathered from various manufacturer sites, reviews, etc. There is much info to be had out there for the internet info hound.

I apologize now if any of this or what else I have posted today (all the motor info) is yours, copywrited, etc. All of this info is stuff that I have culled in my many late night searches for help. I have multiple folders that are split up for info, but I never copied who, what, or where I got them from - just the basic info that I was looking for at the time or if it looked like I might need it later. If this is a problem, please feel free to delete my posts or "pm" me and I will be happy to do so.

I know we have a user here AEAJR (Ed A.) that has helped me and many others on another forum with understanding e-flight and the workings of it. He posted some fantastic info on batteries, current draw and even how props can effect those. Its great for the new modeler to understand how and why he/she should or shouldnt run a certain combo. It was written in normal laymens english so you wouldnt have to try and fudge your way through a program like motocalc without really knowing how or why the numbers are being changed. Maybe we can get him to re-post that info here. It helped me a lot and I have that saved as well

[AEAJR]

frvrngn,

Thanks for the kind words. I am glad to hear that some of my material has been helpful to the community.

I think the piece you would like me to repost is this one, but if it is another, let me know. I might still have it. I spend a lot of time developing these and I do save most of them for the next person who has the same question.

=======================================

AMPS, VOLTS, AND THINGS THAT YOU NEED TO KNOW ABOUT THEM!

This note is intended to clear up a few terms and concepts around electricity
as it applies to electric airplanes.


Think of electricity like water. Volts = pressure Amps = flow

Volts is like pounds per square inch, psi. Says nothing about how much water
is flowing, just how hard it is being pushed. You can have 100 psi with zero
water flow.

Amps is flow, like gallons per hour. You can have flow at low pressure and
you can have flow at high pressure.

Amp hours is how much flow can be sustained for how long. It is used as a
way of measuring how much electricity is in the battery. Like how many gallons
of gas in your tank. It is a capacity number. Says nothing about flow or
pressure, it is about capacity.

Amps and mili amps? We are just moving the decimal point around.

1 amp (short for ampere) = 1000 miliamps (mili means 1/1000)

Examples

So a 7 cell NIMH or NICD pack provides 8.4V (pressure).

The motor will draw electricity from the pack at a certain flow rate, or amps.

If you have a have a 650 mili amp hour pack, it can deliver a flow of
.650 amps (650 miliamps) for one hour. If you draw it out faster, it doesn't
last as long. So your motor might pull 6.5 amps for 1/10 of an hour, or about
6 minutes.

A 1100 mah pack has double the capacity of the 650 mah pack, so it should
last "about" twice as long.


What is C in relation to batteries?

C ratings are simply a way of talking about charge and discharge rates for
batteries.

1C, = 1 time the rated mah capacity of the battery. So if you charge your 650
mah pack at 1C, you charge it a 650 miliamps, or .650 amps.

1C on a 1100 pack would be 1.1 amps.

2 C on your 1100 pack would be 2.2 amps

Motor batteries are often rated in Discharge C and charge C.

So a 1100 mah pack (1.1 amp hour) might be rated for 10C discharge, so you can
pull 11 amps ( flow ) without damaging the battery.

Then it might be rated at 2C charge rate (flow), so you charge it at 2.2 amps
(2200 mah)

How did I do? Things clearing up?

If you have a 500 mah pack - any kind - and it is rated at 16C that means it
can deliver 8 amps.

If you have a 1000 mah pack - any kind - and it is rated at 8C that means it
can deliver 8 amps.

If you have a 1000 mah pack - any kind - and it is rated at 12C that means it
can deliver 12 amps

If you have a 1500 mah pack - any kind - and it is rate at 8C that means it
can deliver 12 amps

If you have a 1500 mah pack - any kind - and it is rated at 20 C that means it
can deliver 30 amps.

If you have a 3000 mah pack - any kind - and it is rated at 10 C that means it
can deliver 30 amps.

So, if you need 12 amps you can use a pack with a higher C rating or a pack
with a higher mah rating to get to needed amp deliver level.


One last point. Motor batteries vs receiver batteries

Some batteries can sustain high discharge rates. Others can not.

Those used as transmitter/receiver packs typically are made for low flow/amp
rates while those made for motor packs can sustain higher rates.

So, having a 600 mah pack does not tell you if it is a motor pack that can put
out 6 amps, or if it is a transmitter/receiver pack that would be damaged if
you tried to pull power at 6 amps. It is enough to say that they are
different.

Clearly a motor pack could be used for a transmitter/reciever job, but a
transmitter/reciever pack should not generally be used as a motor pack.

Basics:
http://www.modelaircraft.org/mag/FTGU/Part8/index.html

Lithium Batteries
http://www.rchobbies.org/lithium_battery_breakthrough.htm

New Electric Flyer FAQs
http://www.ezonemag.com/pages/faq/a105.shtml

[AEAJR]

Maybe it was this one:

===============================


BATTERIES AND BATTERY CHARGERS

Let's look at batteries and chargers. Let's just say that you need to use the
right charger for the
right battery. Don't mix and match or you could create a dangerous situation.
Used properly they are all safe to use. If you want to know more about NIMH,
NICD and Lithium batteries, these links contain useful information.

Battery Basics:
http://www.modelaircraft.org/mag/FTGU/Part8/index.html
Notes on Lithium Batteries
http://www.rchobbies.org/lithium_battery_breakthrough.htm
safety warning on Lithium Batteries
http://www.modelaircraft.org/safetycom.asp


Transmitter and Receiver Batteries

These are typically made
from NICD or NIMH cells that are designed for lighter loads than motor
batteries. As such, they need also to be charged at slower rates. The
general rule is 1/10 C charge rate where C is the rated capacity of the
battery. So, on a 600 mah transmitter or receiver pack would be charged at 60
mah. At this rate you would charge an empty pack for 10 hours to bring it
fully up to charge adn in fact you have to charge them a little longer than
that to really get them fully charged, so figure 12 hours to be sure. This is
handled nicely by the charger that comes with the radio system. This is an
example of such a charger.
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXNK66&P=ML

Quick charging these packs is not recommended as a standard practice.
If you quick charge them, they will likely get hot. Don't quick charge them
in the plane or the radio as the heat build up could damage some of the
surrounding electronics or might deform plastic or epoxy based components near
them. Fast charging at 1C will generate a lot of heat and can lead to early
pack failure which could happen during a flight.

There are after market chargers that are focused on transmitter and receiver
packs. Here is an example from AccuCycle
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXL357&P=ML

Charge 'em slow and treat them right and they should last for years. If you
tend to fly for long periods, pick up an extra transmitter and/or receiver
pack and charge them slowly, at home. Here are a couple of examples.
http://www2.towerhobbies.com/cgi-bin/WTI0095P?FVSEARCH=futaba+battery&FVPROFIL=++
http://www.amondotech.com/index.asp?PageAction=VIEWCATS&Category=228


Motor Packs

The motor on the typical parkflyer needs to pull power at a much higher rate
than a receiver pack can provide. So the batteries that power the motors are
typically of a different design/grade so that they can supply electricity
at these rates. As a result when we charge them we can charge them much
faster too.

The general rule here is that NICD motor packs can be charged in the 1.5 - 3C
range with 2C typical. NIMH packs are best charged at 1- 2C with 1.5C
typical. Higher performance packs can take the higher rates. See what the
maker recommends. This way you can get in your flight, then put the battery
on a charger and be ready to fly that pack again in 15 minutes to an hour.
Have 3-4 packs and 2 field chargers and you may never have to stay on the
ground for more than a few minutes. That's the way I do it.

Lithium motor batteries are becoming popular. However their chemistry is very
different from NICD and NIMH cells. As a result they need a different type of
charging process. If you are using Lithium packs, you MUST use a charger that
is specifically designed to charge lithium or you could end up with an
explosion and/or a fire. This is not joke. Don't ever put a lithium pack on
a charger that is not designed for lithium cells. Follow the charge rate
recommendation of the battery maker carefully!
Video of a lithium battery being overcharged.
http://rc.andersh.com/video/lithiumbattery.wmv

S and P terms

When we talk about battery packs, a designation of XSYP is sometimes used.
This indicates how may cells are in serial and how many groups of these cells
are connected in parallel. While the terms are most common in the Lithium
world, they can just as easily be applied to NIMH or NICD packs.

So a 3S2P pack is made up of 6 cells. There are two groups of 3 cells. The
three cells are connected in series. This is the 3S designation. When
connected in series their voltages add. So 3.7V Lithium cells in a 3S
configuration would have a voltage of 11.1V and be designated as a 3S1P pack.
If these cells were rated at 2000 mah each then this would be a 3S1P 11.1V
2000 mah pack.

Now if we took two of these 3S1P packs and connected them in parallel, the
capacity adds, not the voltage. So this would now be a 3S2P pack rated at
11.1V and having a capacity of 4000 mah. Like connecting two gas tanks
together. The motor in you truck would not be stronger but you could drive
further because you are carrying more fuel.

You could do the same with NICD or NIMH packs. .


Battery Chargers

There are timed chargers and peak chargers. Timed chargers, often bundled
with RTF airplanes, work well if you always run your pack all the way down. If
you have one, use it, but I don't recommend you go out and buy one. Peak
chargers, are the way to go. They read the pack and know when it is fully
charged.

An AC powered charger is convenient to use at home, but won't help you
recharge at the field. All of mine are DC peak chargers except for my radio
chargers. I have a car booster pack that runs my DC equipment in my shop.
And, by the way, I have used it to jump start cars. Works great! This is
similar to the one I have.
http://www.sears.com/sr/javasr/product.do?BV_UseBVCookie=Yes&vertical=AUTO&pid=02 871472000

While many peak chargers are focused on charging motor packs, most also have
low charge rate settings that can be used to charge transmitter/receiver packs
too.

Here are a few examples of peak chargers for your consideration. I have the
first three shown here.

HobbyZone Peak Charger - $19
Simple and inexpensive - I have 2 of these from my Aerobirds I added
different types of connectors so I can use them for all kinds of battery
packs. They work just fine. 4-7 cells NIMH and NICD
http://www.horizonhobby.com/Shop/ByCategory/Product/Default.aspx?ProdID=HBZ1026

Hitec CG-340 - $39 I have had this one for 24 months. This is an older
model. It works well, but there are better choices out there. You need to make
or buy leads Easy to use for NIMH and NICD - up to 16 cells -
http://www.horizonhobby.com/Shop/ByCategory/Product/Default.aspx?ProdID=HRC43340

Triton Charger - $130 - This one showed up under the Christmas Tree - :-)
Better than the CG-340. It handles up to 24 cells NICD/NIMH cells or 4 cell
Lithium cell packs as well as Lead/acid field box batteries.
It will also cycle battery packs which my others will not do. So far I am
very happy with it.
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXCJG7&P=ML
Reviews
http://www.rcbatteryclinic.com/triton.htm
http://forums.radiocontrolzone.com/printthread.php?t=135705
http://www.rcuniverse.com/product_guide/NewProduct.cfm?product_id=19\


I don't have these but have heard good things about them.

GWS MC 2002 Peak Charger - $49
Seems to be a good value for a first charger for NIMH and NICD packs of 4-12
cells. It has charge meter, but not the digital display or memories of the
Triton or others. Includes a variety of connectors. It can not slow charge
receiver/transmitter packs due to 90 minute charge time cutoff.
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXHHV3&P=7
http://www.horizonhobby.com/Shop/ByCategory/Product/Default.aspx?ProdID=GWS3000
http://www.gws.com.tw/english/product/aux%20circuit/charger.htm

AC/DC MRC Super Brain 969 - $95
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXEVC7&P=7
Peak charger, Dual independent outputs to charge 2 packs of 1-8 cells, at
once. Discharge function allows you to get the most out of your batteries LCD
screen shows: battery voltage, charge rate, peak threshold, capacity, number
of cells in pack, & elapsed time For 1-8 cells any capacity NiCd, NiMH
batteries only Selectable charge rate with 0.1 amp increments Selectable
delta peak voltage thresholds in 5mV increments


Great Planes PolyCharge4 DC Only 4 Output LiPo Charger - $100
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXKAU0&P=7
If you are seriously into LiPoly ( not Li-ION) This may be the charger of your
dreams. Charges 4 Lipoly packs at one time. Each charge port is limited to
30 watts, so it can charge 1S or 2S packs at up to a 3 amp rate. 3S packs can
be charged at up to about 2.5 amps and 4S packs can be charged at about 2 amp
rate. Therefore, this charger seems a very good choice for 1S or 2S packs up
to 3000 mah capacity, 3S packs up to about 2500 mah and 4S packs of up to
about 2000 mah. You can charge packs of higher capacity but it will take more
than 1 hour to charge based on the typical 1C charge rate for LiPoly packs.

If you have packs with a 2, 3 or 4P designation, this charger might also be
good for you. 3S4P packs up to about 10,000 mah would work well if each 3S
component can be charged separately. 4S4P packs up to about 8000 mah would
also work, if you can charge them as four 4S1P packs of 2000 mah each.
Discussion thread on this charger
http://www.rcgroups.com/forums/showthread.php?t=354754&page=3&pp=15

A review of a group of Lithium battery chargers
http://www.rcgroups.com/links/index.php?id=4676

Sometimes I have 3 chargers running at the field at one time charging motor
batteries for my parkflyers or receiver batteries for my sailplanes. I hate
being grounded. So they are put to good use.

I invite others to provide insights on the subject or to recommend chargers
that have served you well.

[AEAJR]

OK, let's round it out with this one:

==================

PROPS, WATTS, AMPS AND ......

Your electric motor draws a certain amount of energy to do its job, which is to turn the propeller. With no prop attached it draws very little energy. If you put a big prop on the motor it draws a lot of energy.

This is similar to pulling a boat trailer behind your car. The car might get 20 mpg normally, but put a boat on a trailer behind the car and mileage will drop off to perhaps 15 mpg because the motor is using more energy just to maintain the same speed and travel the same distance. However as long as the boat and trailer are not too heavy, no real damage occurs, you just use more gas.

If you put too big a trailer behind your car, something will break. The motor may fail, the transmission may fail or something else. That is because you are asking the drive train to produce more work, use more energy then it was built to handle. Fuel mileage goes way down and then something breaks. You have over stressed things.

Back to your plane.

Your electric motor needs to "draw" a certain amount of energy in order to turn a given propeller at a given speed. Let's use a speed 400 motor as an example and let's say you have a 6X5 prop on it. That means the propeller is 6" across and has a pitch of 5" per revolution. Pitch indicates how far the prop would move forward through the air if there was no slippage. As either of these numbers go up, the motor is asked to do more work.

Now let's apply some numbers. These are made up numbers for illustration only. Don't assume that these are accurate for your motor in your plane turning your prop.

Let's say that, to turn that 6X5 prop your speed 400 motor draws 6 amps of electricity using a battery that delivers 10 volts, just to make the math simple. That would be 60 watts of energy that the motor consumes to turn that prop. (6 amps X 10 Volts)

If we go to a larger prop, say 7 inches and keep the pitch the same 5 inches, the draw might go up to 8 amps at 10 volts or 80 watts.

Likewise if we went to a 7X6 prop, the draw would go up again, say to 9 amps or 90 watts.

In each case we are increasing the amount of work the motor has to do to turn the prop. The harder it works the more electricity it draws. This is also placing an increasing amount of stress on the motor causing it to generate heat and placing more pressure on the bearings. If we push it too far, the motor will be unable to turn the prop fast enough to be useful in flying the plane and/or it will fail from stress, just like the car example above with the trailer that is too big.

What we are try to do is to get the best balance of propeller and amp draw so that the motor operates efficiently without being over stressed.

Likewise if you have that same speed 400 motor and keep the prop at 6X5 but increase the electric pressure, volts, to 12 volts it will force more amps into the motor. This would be like putting a supercharger on your car's motor which forces more fuel/air mix into the car's engine. It will produce more power so it can do more work. However if we exceed the amount of power it was designed to handle, it will fail. It might not fail right away, but over a very short time it will start to degrade, perform badly and perhaps suddenly fail all together.

If we push the voltage up too high or the amp draw too high, we will over stress the motor and damage it.

The goal is get a good balance of propeller and power draw.

Was that helpful?

[frvrngn]

Actually it was all of those! Thanks for posting! This should definitely be made a sticky. I see these questions asked all the time. It certainly helped me and I still use it now for reference.

[AEAJR]

This is one forum where I am not a moderator so it will be up to the moderator if he feels this is worthy of a sticky.

Clear skies and safe flying!

[AEAJR]

I guess if you found the prop and motor post helpful, then I should finish the thought with the gearbox discussion.

============================

Have you ever ridden a 10 speed bike or driven a stick shift car? Same idea.
Only in this case the motor in that gear box is your legs or the motor in your
car.

Don't know how much you know about cars, but when I was in high school, the
big thing was how low a gear radio did you have on the rear axel of your car?
4.11 4.40 4.88? A 4.88 rear drive would practically rocket the car off the
line, but top end sucked. 4.11 was not as fast off the line but you had more
top end. and so on. Same idea here.

Each gear is set for a mix of power vs. speed. 1st is power, but not a lot of
speed. 3rd is more speed, less power and so on.

Well, in the plane you can't change gears in flight, only RPMs. So by
experimentation you can come up with the best compromise as to power vs. speed
vs. amps into the motor at a given voltage. Try to go up the hill in 7th gear
on your bike and you will wear yourself out in a few pumps, or try to climb
that hill from a stand still in the car in 3rd and it will just stall and
stall, or you ride the clutch and burn it up. That is just like trying to put
too many amps through the motor on your plane. But the motor can't ask you
for a rest, so it burns up. It is all a balancing act.

For $20 you could buy a 400 with a D or a C gear. Pick up a 3-5 different
props for that motor and play. Or for about $12 you could just get the
gearbox and move the motor around, but I would rather get the whole package
and just swap them. You can always use the other one on another plane.


Want to see some real numbers that REALLY show the relationship between prop, amps, volts and gearboxes? Click here and spend some time looking at the charts. All of a sudden it will make all kinds of sense.
http://www.gws.com.tw/english/produc...em/eps350c.htm

You want to play? You want to experiment? With brushed motors in the 280-400
class it is cheap and easy. You just have to make sure the battery pack will
handle it.

If you would just rather drop $75-$200 to get a brushless set-up, by all
means, do it. Me, I am playing with cheap motors right now.

Fun? Interesting?

[Don Sims]

Fantastic info as always Ed. I may combine this one with the basic info thread if we get too many stickies!!

The vast amount of info you've supplied on this thread is incredible. It should help every one, beginners as well as advanced e-flyers.

Thanks for compilling all these posts into one single thread for us.

[AEAJR]

Originally Posted by Don07tncav

Fantastic info as always Ed. I may combine this one with the basic info thread if we get too many stickies!!

Whatever works. I write these to help the new guys so how ever we can put it in place to help the new guys is just fine for me.

[BadTroll413]

Any info like the above that applies to EDF < electric ducted fan > ?

[AEAJR]

I don't have any experience with EDF, but I would imagine you would just treat it like another prop. I am sure there are considerations around the size of the duct and such but otherwise it should be similar. I don't think they use gearboxes on ducted fans because you have an absolute limit on the size of the duct so you can't put in a bigger prop.

I would guess RPMs and pitch are the keys to balancing your EDF.

[Geoff_Gino]

Hi Ed

Great stuff - and all in one place which makes it very easy. Already bookmarked it.

Thanks
Geoff

[oaktown]

Hi, I read your post on batteries and found it very helpful. However I do have a question about it and several other Lipo battery questions.

#1 If you have a 1000 mah pack - any kind - and it is rated at 8C that means it
can deliver 8 amps.

Is the 8 amps the max the battery can draw safely without damaging the battery?

#2 Now if we took two of these 3S1P packs and connected them in parallel, the
capacity adds, not the voltage. So this would now be a 3S2P pack rated at
11.1V and having a capacity of 4000 mah.

So it would not matter if one pack was say rated at 1000 mah and the other was at 1200 mah and I connected them in parallel. So the new capacity would be 2200 mah. Is this correct?

#3 Would there be a problem with let's say I have a 2 cell lipo 1000 mah and I wanted to make it a 3 cell. Does the mah have to be the same when connecting them in series. If I take the 1000 mah 2s and connect in series with a 1200 mah 1s to make the voltage 11.1v. Would this be alright? and vice versa (2 1200 mah cells with a 1000 mah cell).

Thanks in advance for your response.

[AEAJR]

Originally Posted by oaktown

Hi, I read your post on batteries and found it very helpful. However I do have a question about it and several other Lipo battery questions.

#1 If you have a 1000 mah pack - any kind - and it is rated at 8C that means it
can deliver 8 amps.

Is the 8 amps the max the battery can draw safely without damaging the battery?

#2 Now if we took two of these 3S1P packs and connected them in parallel, the
capacity adds, not the voltage. So this would now be a 3S2P pack rated at
11.1V and having a capacity of 4000 mah.

So it would not matter if one pack was say rated at 1000 mah and the other was at 1200 mah and I connected them in parallel. So the new capacity would be 2200 mah. Is this correct?

#3 Would there be a problem with let's say I have a 2 cell lipo 1000 mah and I wanted to make it a 3 cell. Does the mah have to be the same when connecting them in series. If I take the 1000 mah 2s and connect in series with a 1200 mah 1s to make the voltage 11.1v. Would this be alright? and vice versa (2 1200 mah cells with a 1000 mah cell).

Thanks in advance for your response.

#1 Right

#2 I presume you made a typo 1000+1000 = 2000 not 4000 but yes capacity adds in parallel. So your 2 8c packs now make up 1 3s2p pack. at 8C against the 2000 capacity, the pack can now deliver 16 amps.

8C defines the max amps the maker recommends you draw. You might be able to draw more, but the expectation would be that it would damage the pack.


#3 - Danger, Danger! Lipo fire imminent
We never want to parallel packs of different size because they are going to drain at different rates. This could result in one pack falling below the minimum safe voltage while the other still has life in it. this could ruin the smaller pack or, worse, cause some kind of dangerous event. Most likely you would just damage the smaller pack, but with Lipo you can't be too careful.

Likewise we parallel packs so we can deliver higher amp rates. If one pack runs down faster, it will not be able to carry its share of the amp load and the other pack will be over worked and possibly damaged that way.

Also, if you are going to parallel packs, make sure they are of the same C rating to, again, make sure you don't over work one of them.

[oaktown]

Sorry, I didn't know how to reply with the quote (the box with the original post) So I used italics. The number 2 was not a typo but actually your original post, just left off the part about it being a 2000 mah pack.

So about both post 2 and 3. You want the packs or cells to have the same capacity (e.g 1000 mah) and same discharge rate (e.g. 8c) no matter what if you were going to run them in series or parallel.

Now this brings up a new question for me.

How do you find out (measure) the capacity (mah) and discharge rate (c) of a cell/s and or pack?

[AEAJR]

Originally Posted by oaktown

How do you find out (measure) the capacity (mah) and discharge rate (c) of a cell/s and or pack?

You have to get this info from the maker. You can not figure it out for yourself.

[Mad Joe]

wow, this has opened my eyes. Finally the term Li-po says more to me than fat removal. I consider myself fairly well informed on most things electrical, especially DC, but the batteries have always been a little mystery to me. Thanks Guys

Sticky this one!!!

[pelon_mx]

Tnx Ed, as I can see I have a lot of homework to do

[jambo101]

As a total newb to the idea of flying electric planes all the tech stuff is overwhelming me.Unlike my 15yrs experience in stunt kites where you just have to worry about 2 0r 4 lines the wind and which kite to use http://video.google.ca/videoplay?docid=-5994725844500524143&q=stunt+kitewhere
This potential airplane hobby is starting to look like many years of crash,crash,crash,$$$$,$$$$,$$$$, and trying to absorb all the tech stuff that this post seems to exemplify very well

[AEAJR]

Originally Posted by jambo101

This potential airplane hobby is starting to look like many years of crash,crash,crash,$$$$,$$$$,$$$$, and trying to absorb all the tech stuff that this post seems to exemplify very well

Actually this hobby is very easy if you take the RTF route. That is how I got started. Why dig through all this STUFF, just so you can learn to fly?

Most of the better RTFs are pretty easy to fly and pretty tollerent of the mistakes that new flyers make. Pick up a simulator if you want some good practice first.

There are sticky threads here on Flight Simulators, Six keys to success, and other flying focused topics.

Just as you don't have to know how to tear down an engine to buy a car, you don't need to build a plane in order to fly. The work has already been done for you.

The RTFs typically take less than an hour to prepare. Usually it takes longer to charge the motor battery then it takes to put the plane together.

Many of the RTFs are made of foam and plastic which is very tough to break and easy to fix, so you can ease into that part too. And replacement parts are readily available and cheap! Destroy a Sky Fly wing and a brand new one is $10, for example. Destroy the tail of an Aerobird Challenger, $9.95 and 10 minutes to install it so you are flying again. I tell people to buy a spare wing and keep it in the box.

You can get into the tech stuff if you like, but there is absolutely no need if you would just rather fly. You can mess with all this tech stuff later, if you like, or you can keep going on RTFs. There is a pretty wide selection now. There are beginner RTFs, intermedite and advanced RTFs. There are electric, glow, heli and glider RTFs too.

Typically after one or two RTFs, you feel confident and move on to ARFs or kits. Then you only need to know some of what is in this thread as usually the MFg recommends a power system. Just follow their advice and you are all set.

This stuff is primarily for designers.

See? Easy!

[jambo101]

Thanks AEAJR i needed that bit of moral support.Now which rtf unit to buy?

[AEAJR]

without knowing a lot about you, the ones I usually recommend:

For small flying spaces:

parkzone Slo-V

If you have at least 600X600, aprox 4 football/soccer fields or two baseball fields outfield to outfield.

In order of preference:

Multiplex Easy Star

www.readytoflyfun.com T-Hawk

Hobbyzone Aerobird Challenger or Super Cub

Hobbico Sky Fly

[AZ SABRE]

On my Scratch built T-28
WS= 48"
Weight= about 50 oz.
I have no idea which motor, prop, battery to install
I am new to RC and don't understand the nomenclature in the Model magazines. What goes with what?
I need recommendations for the following and where to buy it (website):
MOTOR:
SPEED CONTROL:
BATTERY (PREFER LI POLY)
BATTERY CHARGER:
PROP (PREFER 3 BLADE):

[aahmk]

thanks for explaining