Lone Star Charles

Thanks for the response and thanks for your patience with me. After re-reading post #5 and the links that you provided, and applying the infospecifically to model aviation,see if you thinkI have this right.

1. The motor would not be considered a 3-phase AC induction motor, but a brushless DC (BLDC) or an electronically commutated motor (ECM).

2. I could not figure out whether there were permanent magnets in these motors. I've never held on in my hands or had the opportunity to take one apart.

3. I still could not figure out how the speed was controlled. I can only guess that it is either constant frequency-pulse width modulated, constant pulse-frequency modulated, or a combination of both. From the graphs that I looked at,I strongly suspect that it is only the frequencythat is modulated. Perhaps you could clarify?

Again, as I stated in my original post, none of these questions seems to have a whole lot of importance in how to hook them up or to operate the systems, it's just my own curiosity about how things work. Thanks so much for sharing your experience.

Thanks
Charles

aeajr

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See my comments below ...

Lone Star Charles

Thanks, Ed

It's good to know that there are guys like you in this hobby that not only have a ton of experience, but also willing to share with those of us who are learning. I'll let you know when we finally make the plunge into electrics. There will probably be some 'teachable moments" involved in that.

Charles

harleykingofdividson

Hi guys I am new to EDF's and need some advise/help. I purchased a real nice 90mm F-18 foam last year and just got around to building it. I got it from a dealer in Hong Kong and I dont know te manufacturer because the plane cam in a different box. I need help with the motor or the ESC. I had everything hooked up and was calabrating the landing gear when I smelled that plasticic melting smell. I dropped eerything and started feeling the wires to see if any are getting hot. The esc was very warm but not so that would make that smell. I then tried to test the flight controls and motor. Thats when strange started. Flight controls started moving on their own moving intermiten and then the lights on my RX went out and got the smoplugged the battery and started looking at the wireing to see if there was a problem but did not see one. I plugged the battery in and did not get anything, I tried to bind the rx and did not get the flashing lights. Frustrated I walked away from it to calm down and come back later to look at it again with different eyes. I looked in the tail pipe and noticed that the wires leading from the brushless motor are deformed but not showing wire. Is there anybody out there that can tell me if I burnt the motor and need to replace or the ESC is bad and needs to be replaced?

Specs:
All was incuded with the model except battery, TX and RX

Battery size recomended in instructions and I purchaced - 3800 mAH 5S 18.5 volt Li-Po flight power EON. Battery was about 35% cost of airplane so I have some cash in this.

Thanks for any help you can give me,

aeajr

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harleykingofdividson

Sorry to hear about the problem with your jet. However this is not the right place to post this question. This is a general knowledge thread about electric flight, not a place to have your individual plane debugged.But Iwill try to give you some advice on the process of figuring things out.

First, if you smell burnig plastic and you see deformed wires it is clear you overheated something.Sounds like you overloaded your ESC, or failed to provide enough cooling air to keep things from overheating.If wires are deformed, and you smell burning plastic,that is a sign of overheating.

It is also possible that the wire you are using is too small for the amperage you are trying to pull. This will cause the wire to heat up and if it gets hot enough it might break a solder joint or cook the ESCor the battery.

Try using a receiver battery or another ESC to see if you can get the receiver working. If the receiver comes up and your servos work then I would assume you fried the ESC.

You may want to invest in a Wattmeter. If you dont' know about wattmeters, look at the table of contents in the first post of this thread and find the chapter on Wattmeters.

I suggest you post your questionin the Electric forum in the jet/ducted fan section as these guys will have more specific knowledge about your individual plane and ducted fans.
http://www.rcuniverse.com/forum/forumid_198/tt.htm

Best of luck getting it sorted out.

xinan1000

here i fly using electric. its easy...no need to thing so much.................really essy..........hahaha
im enjoy my flight...


http://www.youtube.com/watch?v=mHba8...eature=mh_lolz

filtr-RCU

HI aeajr

As earlier to my emails I was wondering if you could explain the formula for flight times with this set time. I would like to set my counter on my radio at a starting point and work from there.
Also could you please explain what KV means it is just not make sense to me.

Thanks

Power 52 Brushless Outrunner Motor, 590Kv
Product Specifications
Type: Brushless Outrunner
Size: Equivalent to or surpassing the power of a 50- to 55-size 2-stroke glow engine
Recommended Prop Range: 4S: 14 x 7 - 15 x 8; 5S: 13 x 8 - 15 x 7; 6S: 11 x 10 - 12 x 8
Voltage: 14.8V-22.2V
RPM/Volt (Kv): 590
Resistance (Ri): 0.016Ω
Idle Current (Io): 2.3A @ 18.5V
Continuous Current: 65A
Maximum Burst Current: 75A
Cells: 14-20 Ni-MH/Ni-Cd or 4-6S Li-Po
Speed Control: 80-Amp
Weight: 12.2 oz (346 g)
Overall Diameter: 2.00 in (50mm)
Shaft Diameter: 6mm
Shaft Length: 3.1 in (80mm)



G3 Li-Po 22.2V 5000mAh 6S1P 35C

Voltage:22.2 V
Cells: 6 Cells
Capacity:5000 mAh
Charge Rate: 3-5 C
Discharge Rate:35 C

Sig Kadet LT-40 Weight 6 Lbs

50 watts per pound = Casual/scale flying

75 watts per pound = Sport flying and sport aerobatics

100 watts per pound = aggressive aerobatics and perhaps mild 3D

150 watts per pound = all out performance.

Weight: 6 LBs
Discharge rate is 35C
Watts needed is 600 Watts Formula 100 Watts X 6Lbs = 600 Watts
AMPS needed is 27 Amps Formula 600 Watts / 22.2 Volts = 27 Amps

Bob Mears

Im wanting to build an electric control line combat plane. I need it to run hard and fast for 4 minutes. It needs to run 100 mph if possible. Its a 48" wing and 250 grams without the power system. Could you help me with picking a power system? I dont know crap about electrics, and dont want to go through a long and expensive learning curve. So is what Im asking for available yet, or do I still need to wait a few years? Our FAI engines that the electrics will be replacing weigh about about 150 grams.

Bob

aeajr

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Helping you pick components for a specific plane is not what this thread is about,. This is a book about understanding electric flight and how to understand motors, batteries, speed controls and the rest. If you read the book you will understand what I am about to do.


Using WebOCalc, a free tool I will put in your paramaters.
Wing area is not important for this work. I put in 200 sqinches
Single prop and Iset it at a max of 10 inches
http://flbeagle.rchomepage.com/softw..._imperial.html

Iwork in ounces and pounds, so if your plane weighs 250 grams, that is 9.6 ounces. Iam going to round that to 10 ounces and add 6 ounces for the power system, battery, servos, etc, taking it 16 ounces or 1 pound. I am going to set the watts/pound target at 200 because I want a lot of power to create that kind of speed.

Going to WeboCalc Iput in the numbers.

I have to pick a battery voltage - I pick 3 cell.

An 11V battery will draw about 19 amps to hit 200 watts, so lets put that in as a starting point.

I am going to assume an in-runner because we are looking for speed rather than thrust and inrunners tend to be higher efficency

Now I have to pick a kV for the motor. This is a trial and error thing.WeboCalc can suggest some kV numbers. I will start wtih 2000 Ipick 2000 kv as a starting point and we can adjust from there. Let's see what Webocalc suggests.

After playing with the amps and the kV numbers Webocalc suggests

Using a 2800 kVmotor and a30 amp target on a 3 cell lipo with a5X4.5 prop for a pitch speed of 109 mph.That would probably do it.

So you go look for an in-runner with those specs, an ESC that can handle that and a battery that can safely supply 30 amps.

There are other more elegant programs, but as a first cut I often use Webocalc and just play wtih the numbers till I get what I want.

Where did all these numbers come from? Well, this is an e-book on electric flight. You have to read the book. As I said, this is not a thread where we pick the components for your planes. This is a book that teaches you how to do it.

Happy reading, or happy flying if you want to take those numbers and go shopping.

goirish

Ah!!! Could you go over that again. [8D]

RAYGIB

My Feedback: (32)

I need help! I've converted my Hangar 9 35% Extra 230 to electric power. The motor is believed to be a Hacker A150, which is rated at 8000 watts, 44.4v and 200 amps. I have a 200 amp Turnigy Monster ESC and 4 Turnigy 5000 mah 6S LiPos in a series parallel conbination delivering the 44.4+ volts and somewhat over 200 amps (measured with a 200 amp ammeter with a 75mv shunt). It flew once for under a minute before the power died and dead sticked in. However, power was there to taxi back. Holding the plane down for testing, with the ammeter in series between the batteries and ESC, the set up will pull just over 200 amps at full power, but only for 20 or 30 seconds before it shuts down uncommanded. The motor gets quite warm in that short time. Even when started from ambient temperatures sometimes the motor will drop off line at only 70 amps when the power is coming up. The voltage from the 4 LiPos never drops below 42 volts, even under full power, so low voltage would appear to not be the problem, although anythings possible. If the power is brought up very slowly, full power may be attained, but it usually doesn't last more than 30 seconds. Anyone any ideas on how to fix this short of putting the DA 100 back in?

aeajr

My Feedback: (2)

Believed to be a Hacker A150? You don't know? Which model of the A150? And if you don't know what it is where are you getting the specs from?

Do the math. 8000 watts at 44 volts is 181 amps. You are overloading the motor with 200+ amps. 200 amps at 44V is 8800 watts, which is 10 % over the motor's rating. Assuming this is a Hacker A 150, it is rated to 9000 watts/204 ampsfor 15 seconds ONLY. And the recomended ESC for that motor is a 220 amp ESC.

Hacker motor specs:
http://www.hacker-motor-shop.com/e-v...&t=3&c=35&p=35
Depending on model the motor can handle 150 or 188 amps.
Recommended prop is 27X12. What prop are you using?

You say you are pulling over 200 amps on a 200 amp ESC. You are overloading the ESC!

And you wonder why the system is shutting down? If it did not shut down it would catch fire.

I would bet there is a good chance you have damaged the ESC. Whether you have damged the motor I can not say but this is not a good combination of components.

You could prop down to reduce amp draw. that might resolve your problem. You don't say what prop you are using.

RAYGIB

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RAYGIB

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Dear aeajr: Thank you for your reply to my inquiry. From someone authoring over 7000 posts I will certainly pay attention to what you post. However, I’d like to offer a few words in my defense. Living in rural Maine does not present the opportunity to experience much hands on education on big RC airplanes, particularly electric ones. No one in this area has seen a motor of this size, let alone run one, so we must experiment to some degree. As for my not knowing the pedigree that the motor, let me state that I purchased it at auction, and it came with no paperwork or instructions, and the motor itself has no markings whatsoever on it (see attached picture (I hope)), no logo, manufacturer, model or serial number. The price was right, so I purchased it and the seller stated that I might find some information on a Hacker webpage. Upon doing so, I came across a web page showing the Hacker A150-8. It certainly looked like the motor in my possession, the dimensions were identical. Consequently, I concluded the motor I had was a prototype of the A150, or a ‘knock-off’. A web page from Aero-Model had a list and description of all Hacker motors, including recommendations for the A150-8. This page showed the same model number for two motors, the difference being one operated on, apparently, two 6S Lipos in series at 42-44 volts and 155 amps (as you point out in your post) and the other on 7S in series for 48 volts and 188 amps. I chose to operate at the lower voltage and wired two Turnigy 6S 5000 mah LiPos in series to obtain the 42-44 volts. An identical set was wired in parallel with the first set to add flight time. A Turnigy 200 amp Monster ESC was purchased to complete the system. I did consult with a knowledgeable colleague living some distance away and described what I was doing and he had no concerns, saying it sounded OK to him. Of course, hindsight is better and I should have put an ammeter in series between the batteries and ESC and run some tests but none were available anywhere local so I had to order one, along with its external shunt. The motor responded during the initial turn on with the proper sounds, the recommended size Xoar 27 X 12 wood prop spun in the proper direction and all seemed well, I did not do a full power test prior to the first flight but did run it up quite a bit and there was plenty of power. You know the rest. When the ammeter arrived and was inserted I was quite surprised that the system was running at just over 200 amps at full throttle! You are probably correct in assessing that the ESC could be damaged. I have not tried to run things again until I can get a smaller prop to drop the amperage. What size would you recommend? Effort was made to keep things in their proper range, but with the recommended prop the current draw is too high. You are, of course, correct that 8000 watts at 44 volts is 181 amps. I was expecting the amperage to be around the recommended number of 150, and thought a 200 ESC would be plenty. I am aware the recommended ESC is a 220 amp one. Perhaps this undocumented motor has a problem. I’ve requested Aero-Model to examine and test it, and haven’t heard back from them at this point. Sorry I’m so long winded, but the details are important. Again, thanks for your thoughts and perhaps you could recommend a prop size.

aeajr

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Ray,

This thread is a book.I presumed you had read it before coming to ask these questions. The book is about understanding electric power systems. Perhaps, before you go any further you should read the book to understand what you are working with.

Here are the challenges.

I have no idea what motor that is. If it were a hacker it would say hacker, like this one:
http://www.aero-model.com/Hacker-Brushless-A150-10.aspx

I don't even know if it can or should run on 44 volts I don't know the kV rating or the max amps,so I have no basis of a recommendation other than to say it should be something smaller than what you have now in order to not overload your ESC.I have no idea what the motor can take but I know your ESC can't take over 200 amps.

You mention, "the recommended size Xoar 27 X 12 wood prop spun in the proper direction and all seemed well," . Who recommended this prop? What was the recommendation based upon? Or are you saying that would be the recommended prop for a Hacker motor, if this were a Hacker?

The motor you have may have no relationship to a Hacker motor and have nothing in common with the Hacker. If the kV rating is different than NONE of the Hacker specs will apply.

Sorry, I wish I could be more helpful. Perhaps you should start a discussion in the giant scale section. Someone there might recognize the motor.

RAYGIB

My Feedback: (32)

Thanks for reading my 'book'. I don't know what it is either.....so I'll post a pix in giant scale.

bobcom52

Hi Ed, I have previously read your book via Ken Myers site. Good work, I refer newbies to both Ken's and your articles.
Just a very small point. In post 3 you state that brushless/ ESC combo may be about 4 times the cost of brushed equivalent. Perhaps that needs updating as I think they are about line ball these days.
regards
Bob Comerford

aeajr

My Feedback: (2)

Good point Bob although the cost range of brushless motors can still be pretty broad. You can buy a 100 watt brushless for $15 or $30, just like anything else. Likewise with the controllers. If we look at the lowest cost brushless/controllers vs. brushed can motors and controllers, there is still a premium but it is not as much at the lowest end..

You can buy a speed 400 for $7 and controller for 10. The brushless are not quite there yet, but the drop has been dramatic from when I posted that article. Time for an update, so I made some revisions and posted an updated article.

Thanks for the suggestion.

aeajr

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Replaced with the next post

aeajr

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jzrf6c

Just trying to join this thread and receive emails.

aeajr

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Welcome to our happy little family.

jzrf6c

Thanks. I'm looking forward to learning a lot more about electric flight.

aeajr

My Feedback: (2)

Folks, after reading the chapters, feel free to ask questions. The book was done in this format so that people would read and ask. So, feel free to do so.

aeajr

My Feedback: (2)

This book has extended beyond the strict focus of electric power system and
electric powered flight. Here, again, I will add an article/chapter that will be
helpful to the electric pilot but is not unique to electric. This is the same
process I use for gliders and the same process that one would use for glow, gas
and jets. I presume it applies to quads and copters too.


BASIC SERVOS SET-UP PROCESS
by Ed Anderson

If you are using a computer radio, establish a new model in a new memory slot
-Bind the receiver to the radio or memory slot

Before you put the servos in the plane connect them to the receiver on the channel
they will be on when mounted. This will center them and you can confirm they work
properly. Better to find out BEFORE you mount them. If you are going to have a
matched pair, such as two flaps servos, see if they move together exactly the same.
There can be slight variations between servos.


-Mount the receiver and servos with the control arms off or in a way that you can
remove them if possible. This allows you to re-position the servo arms as part of
the trimming set-up but make sure you can get the screws on the servo arms after
you are done.


-Mount the receiver and servos
-Connect the servos to the receiver

-Confirm you have each servo on the correct channel
-Confirm it is moving in the correct direction – use servo reverse if it is not.
-Connect the servo to the control arm

With the radio on, confirm that all the trims are centered.

Check to see that the control surface is centered and the servo arm will move freely
.....check for binding
.....check for flex of the control rod
.....check for restrictions that might block the servo from moving smoothly

If the surface/servo are not properly centered don't go to the radio first, center the servo mechanically as much as possible.
..... Lift the control horn off and reset it so that the surface is centered
......Adjust the clevis to center the surface.

Set your control throw using mechanical linkages as much as possible
...... use the control horn hole that is closest to the surface for the largest throw – furthest to reduce throw
.......use the servo arm hole that is furthest from the servo for the largest throw – closest to the servo for reduced throw
.......Only after doing this should you use the radio's subtrim, ATV/EPA features to do any centering or control throw adjustments.

When you have one servo right, then do the next till you have them all working correctly.

If you have flaps, make sure they move together, smoothly.

If you have flapperons, make sure they move as flaps together, smoothly.


How to select your first radio
http://www.modelaircraft.org/insider/13_09/first%20radio.htm