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Beginners New to e-power flying? Get the low down in here from experienced e-power RC pilots!

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Old 12-13-2008, 11:38 AM   #26
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Hobby City has some great deals on motors and ESC. I just purchased a set-up from them. Unfortunately the motor was defective.

They immediately issued a return authorization, but to send the motor back for warranty service will cost me as much as the motor. So it goes in the trash. I purchased a Great Planes Rimfire to replace it.

Nothing wrong with buying bargain basement motors from Hong Kong. Just realize the risk you take and don't forget to take the shipping charge into account.


Asking about specific motors, ESC, prop and battery combos is a good idea. However, if you want accurate answers I STRONGLY encourage you to post links to the items you ask about. Don't make us go hunting to try and find the items you list. Unless we have that exact set-up, we are going to have to read the specs and to do that we have to spend a LOT of time hunting for the items. That is a big waste of everyone's time. and prone to errors.

I was in a thread the the other day where people were giving the guy all kinds of advice. Unfortunately the motors they were talking about were not the motor he was buying, but they didn't realize that and neither did he. So he got a lot of wrong info from people who did not realize it was wrong.

If you are still interested, post links to the items you are considering.

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Old 12-13-2008, 03:02 PM   #27
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Originally Posted by AEAJR View Post
Hobby City has some great deals on motors and ESC. I just purchased a set-up from them. Unfortunately the motor was defective.

They immediately issued a return authorization, but to send the motor back for warranty service will cost me as much as the motor. So it goes in the trash. I purchased a Great Planes Rimfire to replace it.

Nothing wrong with buying bargain basement motors from Hong Kong. Just realize the risk you take and don't forget to take the shipping charge into account.

Ed,

A suggestion I find helpful in my HobbyCity/HobbyKing purchases: a few members of my club will make purchases en masse and we then split the shipping based on weight of our items. It helps to cut down the costs some. Of course, in the case of a dead motor, well, that would still suck. But I agree shipping needs to be taken into account when purchasing from China, and doing it with a group can help make it a more cost-effective method.

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Old 12-13-2008, 06:34 PM   #28
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Thank you for your reply. It seems to me that a 2050 Kv motor with a 1300 Ma Lipo swinging a 6/3 folding prop with a 20 Amp ESC would be enough power for a 20-24 oz aileron glider. (Dyna Flight Talon). You being the expert I thought perhaps you would have a "gut Feel" for the set up. I apologize if I've inconvienienced you. I read the reviews for the componets that I mentioned and they were all favorable. I often read your threads and was seeking some expert advise.
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Old 12-26-2008, 03:52 AM   #29
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A bit of a trap-some time back bought 1st brushless motor NOT my LHS ,and sold me a Eflite 370 outrunner 1360v which he matched up with a Dualsky 12amp ESC, was for one of early s/sticks , anyway used to fly -just, but thought bit underpowerd as blogs all said how well brush/L wizz up, ...well much later on & planes/crashes solder & fix, tested the now discarded 370 on a differant ESC (and vice verse it on 400 Brushless which ran at about 1/3 speed!) , -WELL did it really pull heaps on 7.4v only, So all that time the reason was a faulty Dualsky! hope helps new flyers~
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Old 12-26-2008, 06:31 PM   #30
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Originally Posted by Wicker Bill View Post
Thank you for your reply. It seems to me that a 2050 Kv motor with a 1300 Ma Lipo swinging a 6/3 folding prop with a 20 Amp ESC would be enough power for a 20-24 oz aileron glider. (Dyna Flight Talon). You being the expert I thought perhaps you would have a "gut Feel" for the set up. I apologize if I've inconvienienced you. I read the reviews for the componets that I mentioned and they were all favorable. I often read your threads and was seeking some expert advise.
You asked for expert advice. My first advice was to post the specs and links to the components about which you are asking. Without that, there is not basis to advise you on anything else.

You have chosen to ignor that advice.



Originally Posted by Wicker Bill View Post
Hello, I,m interested in the Hobby City C20-2050kv brushless outrunner motor, using the Zippy 13002S20C,1300 MA, ZSIP 20C Lipo battery, and a SUP20A SuperSimple 20Amp ESC. Is this a combination that will work for a 20-26 ounce glider? Can I use a 6/3 folding prop with a 26 to 28mm spinner?
Let me show you what is absolutely requred to properly ask this kind of question. Unless someone has that plane with that motor, that ESC and that battery they will have no way to answer your question without these specs.

HC C20-2050
Dimension23mm x 24mm
WeightF25.5g 0.89oz (kv2050) (not including connectors)
Diameter of shaftF3.0mm(EDF/EDP)
Length of front shaftF8mm

Max performance;
Voltage: 10.5v
Current: 11.0A
Prop: 7035 (GWS)
Thrust: 552g
Power: 129W
http://www.hobbycity.com/hobbycity/s...idProduct=6634

20 amp ESC
Spec.
Weight: 18g
Size: 32x47x4mm
Cells: 2-3S (Auto Detect)
Max Current: 20A
BEC: 2A

http://www.hobbycity.com/hobbycity/s...idProduct=6457

Battery Pack
Spec.
Capacity: 1300mAh
Voltage: 2S1P / 2 Cell / 7.4v
Discharge: 20C Constant / 25-30C Burst
Weight: 80g (including wire, plug & shrink wrap)
Dimensions: 85x34x12mm
Balance Plug: JST-XH
Discharge Plug: T-Connector (Deans Type)
http://www.hobbycity.com/hobbycity/s...idProduct=6469


6X3 Folding prop
Folding Propeller w/ Alloy hub - 6x3
Machined alloy hub.
2~2.3mm Colet style shaft adapter.
Weight: 22g
http://www.hobbycity.com/hobbycity/s...idProduct=5273



This is required info when you post a question about specific components. This way those who want to help you have the proper information. It took me 15 minutes to search for and find this info and post it here. That was before I even started to do ths analysis. Hopefully I found the right stuff.


If you spend the 15 minutes and post the info, we can look, understand and recommend quickly. If you make us go hunting for it, we may come up with the wrong components and make poor recommendations. Or, more likely, people will pass your question rather than going hunting for the info you did not include.


I am not trying to upset or embarrass you. I am trying to teach you how to get the best help from people who want to help you but who may not be wiling to spend their time looking up information that you already looked up.


Based on the specs:

Your motor has no connectors. Your battery uses Deans. You will need to buy connectors and know how to solder. No problem, right?


Do you have a balancing LIPO charger that matches the balance plug on the battery? Will you need to buy an adapter?

I assume you plan to mount the motor inside the nose of the glider. Have you measured the nose area of your glider to see that the motor will fit? This is an outrunner, so you have to make sure the spinning can is not going to touch anything as it spins. I would say you need a minimum of 30 mm to insure clearence and working room. 35 MM would be better. And don't forget the wires have to come from the front of the motor and pass around it, without touching it.


In deciding on your mount, you have an 8mm long shaft on the motor and the shaft is 3mm in diamater. Do you have the right prop adapter for this? The specs on the prop say it is for a 2-2.3mm shaft so I think you are going to have a problem.


What is the width of the nose at the cut point. You will want a spinner to closely match that dimmension for best air flow over the prop and the fuse.

The motor is rated at 129 watts based on a 3 cell lipo or an 8-9 cell NiXX pack and a 7X3.5 prop.

You plan to use a 2 cell lipo and a 6X3 prop. You will get a LOT less power out of the motor.

My guess is you will probably get about 50 watts of power, or about 31 watts/pound based on a 26 ounce glider. That will fly the glider but climb performance would be well below what I would consider desirable. I would want at least 50 watts/pound as a minimum target and would want that wider prop.


As for the ESC, there is no indication that it has a brake. And the description on the web site says it comes with no instructions. A brake is vital to make sure the prop does not keep spinning when you move the throttle to zero. A free wheeling prop will absolutely kill the glide of your glider. You need a brake on your ESC.


So, no, I don't think you have a good combo here.



If you want to use that motor and that battery I would go up in prop size. I see hobby city has an 8X4.5 folding prop. but it still looks like it is for a 2-2.3mm shaft. http://www.hobbycity.com/hobbycity/s...idProduct=5271

I don't think they have a folding prop that will fit this motor.


I would look for a motor of about 80-130 watts, based on the kind of climb you want. And I would look for one that has a recommendation of a 7-9" prop.

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Old 12-26-2008, 07:05 PM   #31
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As a follow-on to the post above, I thought I would share some flight testing I have done and my experience with several e-gliders. Read it all, but the Sky Runner mentined below would be the closest to your glider.

I just finished a Cox Dust Devil, 2M RES e-glider. Plane comes in around
41 ounces all up.

I have a Rimfire 35-30-1250 outrunner in it. The recommended prop is a
10X7 on three lipo cells. Bench test showed 305 watts and 26.5 amps on my
wattmeter. That comes to about 120 watts per pound. Frankly, it is way
over powered. Plane goes straight up at full throttle. I would climb at
about 2/3 throttle at most.

During bench testing I decided to try a 2 cell. On the bench It showed 98
watts with the 10X7 prop. I did not fly that combo but I felt it would be
a little weak. That would be about 38 brushless watts per pound. I will
try it at the field, just to see the results, but have not done so yet.

Next I put on an 11X8 on the 2 cell. This comes in about 145 watts on the
watt meter pulling 21 amps, or about 56 watts per pound. Note that these
are "brushless watts" which are more efficient than what you would read off
a typical brushed "can" speed XXX motor.

I tried the 2 cell 11X8 prop combo at the field. Plane climbs at about 60
degrees and is very high in about 20 seconds. I would consider this a good combination.

I had forgotten to set the brake on the ESC, so the prop continued to freewheel, placing a real drag on the glider. I have now reset the ESC and look for an opportunity to see the glider really themal.


Experience from my other e-gliders:

My Easy Glider Electric, 71" wingspan, has about a 160 watt brushless on a
gearbox turning a 9X6 prop using a 2 cell lipo. That is about 80 watts per
pound. At full throttle it will go up at around 80 degrees. At 3/4
throttle it climbs at about 60 degrees and is quite high in 20-30 seconds.
I rarely give it full throttle as I get more climbs at 2/3 throttle as
opposed to almost straight up.

My Sky Runner EP, 49" and 21 ounces, uses a 9.5" prop and is powered at 100
watts per pound. I don't know the pitch specs on the prop. With this combo
it will go straight up. I typically climb at about 2/3 throttle and hit
great height in 20 seconds.

I had an Icon Hawk 2M foam glider with a 160 watt brushless. I think it
used a 9X6 prop. This worked out to about 70 watts/pound. At full throttle
it climbed at about 60 degrees and was very high in 30 seconds.

Conclusion:

For a TD sailplane intended for sport flying, 60 brushless watts/pound will
give you a very good climb when matched with the right prop. Unless you are
flying LMR in competition, you probably don't need more than 75 watts per
pound. That will get you up there quickly. Of course more power will take
you steeper and faster.

I suggest you think in terms of outrunner/battery or
inrunner/gearbox/battery combos that can handle a 8-12" prop for 1.5-2M and
11-14" prop for 2.5-3M gliders.

All of my battery packs are set up to run about 10-12 C giving me 5-6
minutes of run time at full throttle. If my average climb is 20 seconds,
that gives me 10-15 climbs per pack with power to spare. On that, with a
little thermaling skill and a little luck, I can typically enjoy 1-3 hours
of flying on a pack.

This is all just general info, but I thought I would share my experience.
Your mileage and climb experience will vary.

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Old 01-19-2009, 07:58 PM   #32
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Default I dont want to burn my edf jet !!!!

I HAVE THIS SET UP ON MY RICCS MIRAGE 2000 EDF JET:
FAN UNIT IS 64mm
MOTOR IS 4500Kv
ESC IS 25A
LIPO IS 11.1V 1300mAh 15C

MY QUESTION IS WHAT HAPPENS IF I USE A BIGGER CAPACITY ESC, LETS SAY A CASTLE CREATIONS 54 OR 60 AND A BIGGER LIPO, LETS SAY POLYQUEST 11.1V 2000mAh 30C.

CAN THE STOCK ESC (25A) CAN HANDLE A 11.1V 2000mAh 30C lipo???

SOMEBODY HELP ME OUT HERE ??

I DONT WANT TO BURN ANYTHING !!!
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Old 01-19-2009, 08:05 PM   #33
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PLEASE HELP ME OUT.
I HAVE THIS SET UP ON MY EDF MIRAGE 2000ñ
4500Kv MOTOR, 11.1V 1300mAh 15C lipo, 25A ESC, 64mm FAN UNIT.
I WANT TO USE THIS LIPO I HAVE FROM ANOTHER PLANE IS A 11.1V, 2000mAh, 30C, SO, WILL SOMETHING BURN IF I USE THAT LIPO ?? CAN I UPGRADE THE ESC FOR A
BIGGER CAPACITY ONE LIKE CASTLE CREATIONS 54Amp ???
help me out, i dont want to burn any electronics on my plane.
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Old 01-19-2009, 08:13 PM   #34
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Default Melting problems !!!

hello, can you help out.
my edf jet mirage 2000 has this set up: 4500Kv motor, 11.1v 1300mAh 15C lipo, 25A ESC, 64mm fan unit.

can i upgrade the lipo battery for a polyquest 11.1v 2000mAh 30C without burning the 25A ESC ??

IF i use the polyquest lipo 11.1v 2000mAh 30C, do i have to buy a bigger
Esc unit like a CASTLE CREATIONS 54 or 60 or 80 ??

i just dont want to burn anything.

thx.
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Old 01-19-2009, 09:03 PM   #35
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Originally Posted by HERNAN View Post
I HAVE THIS SET UP ON MY RICCS MIRAGE 2000 EDF JET:
FAN UNIT IS 64mm
MOTOR IS 4500Kv
ESC IS 25A
LIPO IS 11.1V 1300mAh 15C

MY QUESTION IS WHAT HAPPENS IF I USE A BIGGER CAPACITY ESC, LETS SAY A CASTLE CREATIONS 54 OR 60 AND A BIGGER LIPO, LETS SAY POLYQUEST 11.1V 2000mAh 30C.

CAN THE STOCK ESC (25A) CAN HANDLE A 11.1V 2000mAh 30C lipo???

SOMEBODY HELP ME OUT HERE ??

I DONT WANT TO BURN ANYTHING !!!
Having a higher capacity ESC is fine. As long as it meets the minimum, it does not matter if it can handle more. Like one person in a 5 passenger car, the car runs just fine.

Same with the battery. The limiting factor on the battery is how many amps can it supply. Your 1300 mah 15C battery can provide up to 19.5 amps if you push it to its rated limit. If you use a 2000 mah 30C battery, which can supply 60 amps, then runing it at 19.5 amps just means the battery is not working hard. Its higher mah rating will also give you longer flight times. Note that it is also likely to be heavier and larger, so that could effect your ability to put it in the plane or to balance the plane.

BTW, I never recommend running your battery packs at more than 80% of their rated max, if you want them to have a good life span. So that 1300, would be best run at 16 amps or less.

Hope that helps.

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Old 01-19-2009, 09:17 PM   #36
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Hello again,

so, the minimun esc for my application is what ?? And the maximun lipo capacity i can use is what ??
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Old 01-19-2009, 09:27 PM   #37
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Originally Posted by HERNAN View Post
Hello again,

so, the minimun esc for my application is what ?? And the maximun lipo capacity i can use is what ??
Minimum ESC is based on the Amp draw of the motor. The amp draw of your motor will be determined by the size prop or ducted fan you use and what voltage battery you use.

I don't know what motor you have so I have no specs. If you go look at the specs for your motor you will see a Max amp rating on it. THAT is your minimum ESC sizing.

Lacking this information, you use a watt meter to read it directly to see what you are actually drawing. Just make sure it is less than the max rating for that motor.

There is no MAX lipo capcity. That question is the same as asking, "what's the biggest gas tank I can have in my car. The answer is the biggest that will fit.

I would recommend you go read the second post again as I belive this is all explained in detail.

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Old 01-19-2009, 09:37 PM   #38
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hello, this is the motor, the one with 4500KV., THE ONE IN THE MIDDLE.
SO, PLEASE YOU TELL ME WHAT IS MY MINIMUN ESC UNIT.



http://www.riccs.cn/comp_content.asp?id=10
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Old 01-20-2009, 03:47 AM   #39
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Batteries2~3 cell Li-PolyRPM/V4800 rmp/V4500 rmp/V4300 rmp/VMax. efficiency80%82%82%No load current2.2 A2.0 A1.7ACurrent capacity35 A/60 s25 A/60 s22 A/60 sDimension20x40 mmShaft diameter2.3 mmWeight 60 gInput Power350 W270 W240 WThrust1350 g/47.5 Oz1250 g/44 Oz1150 g/40.5 OzRecomended model weight400 - 1200 gRecomended propeller11X4.7Use for model Aerobatic airplanes3D airplanes

These are the specs for the 3 different versions of this motor. Is says the max amps for that motor is 25 amps. Lacking any actual measurements, I would say 25 amps would be the minimum. Anthing larger than 25 amps would work fine.

The recommended prop seems to be 11X4.7 on all three of them.

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Old 01-20-2009, 05:02 PM   #40
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MANY THANKS FOR YOUR KIND ANSWER, NOW I HAVE THIS OTHER QUESTION: HOW DO I KNOW I AM RUNNING MY BATTERY PACK AT 80% ??? THAT IT WOULD BE LIKE 50% THROTTLE OR 3/4 THROTTLE ???

"BTW, I never recommend running your battery packs at more than 80% of their rated max, if you want them to have a good life span. So that 1300, would be best run at 16 amps or less".

ALSO, LAST SUNDAY I WAS FLYING MY TREX 600, AND WHEN LANDING IT, FOUND OUT THAT THE LIPO BATTERY WAS LIKE SWELLING, LIKE VERY FAT !!
WHY IS THIS HAPPENING ??
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Old 01-20-2009, 11:49 PM   #41
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DANGER! DANGER! DANGER!

A swelling lipo is a very bad thing and can be dangerous. Get it out of your care or your house and put it in a fire proof area or container.

A swelling lipo indictes a defective pack, a pack that has been over chargerd or a pack that has been over stressed, run at amp rates beyond its ability to safely operate. It can also result from a pack that is badly out of balance.

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Old 01-20-2009, 11:57 PM   #42
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Originally Posted by HERNAN View Post
MANY THANKS FOR YOUR KIND ANSWER, NOW I HAVE THIS OTHER QUESTION: HOW DO I KNOW I AM RUNNING MY BATTERY PACK AT 80% ??? THAT IT WOULD BE LIKE 50% THROTTLE OR 3/4 THROTTLE ???

"BTW, I never recommend running your battery packs at more than 80% of their rated max, if you want them to have a good life span. So that 1300, would be best run at 16 amps or less".
If you use the recommended voltage and the recommended propeller size then you can assume that your motor is drawing at the rate reported by the manufacturer. Good motors come with charts that typically outline what to expect in amp draw based on voltage and prop.

www.maxxprod.com provides a good example. Let's use this one for example. The specific informatoin for this motor is found here:

HC3510-1540
http://www.maxxprod.com/pdf/HC3510-1540.pdf

This document is available on line and is packaged with the motor. It lists 4 different props and a range of voltages that you could use. Using the chart you can see what amp draw you can expect. Based on this you can decide what amperage you need your battery to deliver. Then buy a battery that can deliver at least 20% more than that to be sure you are not over stressing the pack.

wattmeter

The other thing is to get a wattmeter. This is a way to directly measure the power draw of your motor with a given prop. This is the one I use.
http://www3.towerhobbies.com/cgi-bin...&I=LXLMV0&P=ML

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Old 04-11-2009, 10:14 PM   #43
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What is the difference between Heli and Airplane ESCs? I see they are listed seperately and i can se how a Helli ESC would be spinning up a lager bladed causing the initial current to remain hihger longer but why could i not use a Heli ESC in a plane?
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Old 04-12-2009, 01:56 AM   #44
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There's no difference. As long as the ECS has the proper rating for your application.
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Old 04-12-2009, 03:06 AM   #45
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Default Heli versus Plane ESC

Thanks for the reply. I couldn't see how there could be but wanted some assurance
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Old 04-12-2009, 11:42 AM   #46
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Originally Posted by DSW View Post
There's no difference. As long as the ECS has the proper rating for your application.
Well except that many/most heli ESCs DO NOT have the LVC feature to protect lipos from low voltage (because cutting the motor on a heli results in a big crash). Also the programming is often different. Quite a few heli ESCs have various governor modes to set and maintain blade speed and I've hardly ever seen a plane ESC with a governor mode.

But a good heli ESC can often be set up to act like a plane ESC if you program it correctly.

Steve
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Old 04-12-2009, 02:49 PM   #47
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Steve,

Good info. I often wondered if there was a difference. What you posted makes a LOT of sense.

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Old 06-07-2009, 04:38 AM   #48
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thanx for the great info guys
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Old 09-12-2009, 10:31 PM   #49
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I am building a Mountain Models P-51 EP(40). Specs say to use a 40amp ESC, but, it doesn't say anything about the BEC. Do I need a UBEC since there are 5 servos?

If so how big?
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Old 12-02-2009, 05:48 AM   #50
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In reading these and other posts I find that the recomended watts for the plane I plan on building is 250 to 300 watts. Several motor manufacturers give 2 figures One is continuous current and one is maximum or burst current. Can I assume that the 250 - 300 figure I'm looking for refers to continuous current or power?
Thanks for all your help so far.
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