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How does Battery size to Motor size Amp wise

Old 09-30-2013, 10:03 PM
  #1  
RVDriver
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Default How does Battery size to Motor size Amp wise

The Delta Ray has two 15-size brushless motors, and they recommend a 7.4V 2S 1300mAh 20C Li-Po battery, Can I put a larger battery (more mah) and get longer flight time.


I guess what I am saying is how does the 1300mAh relate to two size 15 motors? I know enough not to increase the voltage, also what does the 20C stand for?


Thanks
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Old 09-30-2013, 10:08 PM
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CHELLIE
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Originally Posted by RVDriver View Post
The Delta Ray has two 15-size brushless motors, and they recommend a 7.4V 2S 1300mAh 20C Li-Po battery, Can I put a larger battery (more mah) and get longer flight time.


I guess what I am saying is how does the 1300mAh relate to two size 15 motors? I know enough not to increase the voltage, also what does the 20C stand for?


Thanks
Hi a 15 size brushless is a big motor and a 1300mah lipo is to small to power just one 15 size motor let alone 2 motors, can you add a link to your plane, something just does not sound right here.
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Old 09-30-2013, 10:12 PM
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Ok, I found some specs on that plane, it uses 180 size brushed motors, that sounds more like it if you go to big on the lipo, your plane will get to heavy to fly, the max size lipo i would use is a 1500mah lipo, but the performance of the plane will suffer a little. the specs say the plane has a 8 min duration time, thats a lot, really there is no need to go to a bigger battery.

http://www.amainhobbies.com/product_...FWfhQgodQwgAcg


Specifications:
Wingspan: 34.0 in (863mm)
Overall Length: 31.8 in (807mm)
Wing Area: 384 sq. in. (2480 sq. cm.)
Flying Weight: 17.6 oz (500 g)
Motor Size: (2) 180-size brushed motors (installed)
Radio: DX4e 4-channel DSMX transmitter (included)
Servos: (2) SV80 servos (installed)
CG (center of gravity): 14.4 in (365mm) from the rear of airplane at fuselage center line
Prop Size: 5 x 3
Recommended Battery: 7.4V 2S 1300mAh 20C Li-Po (included)
Approx. Flying Duration: 8 minutes
Charger: 2-cell DC balancing Li-Po charger (included)
Minimum Age Recommendation: 14 years
Experience Level: No Experience Necessary
Recommended Environment: Outdoor
Assembly Time: Less than 1 Hour
Is Assembly Required: Yes
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Old 09-30-2013, 10:15 PM
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You can add more mah... but it adds weight and eventually you get to a point that makes the plane too heavy to do what you want to do.

I commonly have planes carry double the mah recommended. Almost any airplane will fly with the added weight. But I don't attempt any high G flying with the added weight without ensuring the aircraft is capable of handling the added stresses involved. Extreme low speed aerobatics (commonly called "3D") will also suffer from the added weight.

How much extra you can carry varies greatly with what plane you are flying. Some planes can reasonably carry more than double their "ready to fly" weight as cargo or added battery capacity. You won't be doing any aerobatics with something loaded that heavy if you want to keep your wings attached though.
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Old 09-30-2013, 10:18 PM
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[media]http://www.youtube.com/watch?v=FU6w-YuUKGg[/media]
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Old 09-30-2013, 11:33 PM
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Great... a plane designed to teach you a lot of bad habits.
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Old 10-01-2013, 03:49 AM
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Just what do you mean by"Bad Habits" I am new and have not bought this plane yet. Was looking at the Apprentis 15 "with Safe", but it requires a larger field and a landing strip from what I hear. This Delta Ray has the same "Safe feature" and is a "Park Model, from what I hear. Also sorry about the motor size, I cut and pasted it from somewhere on the Internet, goes to show can't believe All you read!
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Old 10-01-2013, 05:59 AM
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Originally Posted by RVDriver View Post
Just what do you mean by"Bad Habits" I am new and have not bought this plane yet. Was looking at the Apprentis 15 "with Safe", but it requires a larger field and a landing strip from what I hear. This Delta Ray has the same "Safe feature" and is a "Park Model, from what I hear. Also sorry about the motor size, I cut and pasted it from somewhere on the Internet, goes to show can't believe All you read!

Dont worry about the bad habit's comment, I'm sure it was made mainly in jest. The Delta ray is a good choice if you are trying to teach yourself to fly, although the best way to learn would always be to find someone to teach you.

Regarding the battery:

There are three variables on a LiPo:
  1. Voltage -this goes up in steps of 3.7V as a result of the number of series cells in the battery. 1 cell in series (a.k.a. '1s')=3.7v, 2s=7.4v, 3s=11.1v and so on.
  2. mAh (milliamp hours) - This is a measure of the capacity of each cell in the battery, i.e. how much charge can be stored.
  3. c rate (e.g. '20c') - 'c' is the discharge constant. Multiply c by mAh then divide by 1000 to calculate the maximum current in amps that the battery is capable of delivering without damaging itself. In your case: 20 x 1300/1000 = 26 Amps (take this one with a pinch of salt as manufacturers often exaggerate c )

As noted above, the problems with increased battery mAh capacity are increased size and weight.
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Old 10-01-2013, 06:07 AM
  #9  
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Bad habits:

1) Hold the stick over in order to make a turn because the radio prevents a full roll from occurring and levels the plane when you let go.
This is a VERY bad habit to form. Proper turn procedure is to establish a bank angle and apply elevator to pull through, adjusting rudder stick to have the fuselage point just slightly inward from tangent to the arc of the turn. The Ailerons need to be returned to neutral or very nearly neutral during the turn then reversed to level the aircraft when the correct heading is reached.

Learning this bad habit will impede your learning to handle other aircraft.

2) the radio handling motor safety (somewhat) to teach you its safe to get your hand in the way of the prop(s)
This is even demonstrated in the video with the plane being handled in a blatantly unsafe manner.

Want me to go on?
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Old 10-01-2013, 01:04 PM
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fhhuber,

I think that's a bit harsh. The idea of the SAFE system is so a complete novice can have a chance of learning to fly an RC plane without crashing. I agree that the best way to do that is to find an instructor but for those who dont have an instructor SAFE appears to be the next best thing.
Sure, in beginner mode the plane is unrealistically easy to fly and wont crash even if you over control it (like a normal plane would) but that's the whole point.
Once you get the hang of what the sticks do and get used to orientation etc then you can switch over to intermediate mode. In intermediate mode the plane responds more like a normal RC model but still prevents it all getting too far out of shape. Then ultimatly you can move to advance which removes all artificial stability and flies like a 'normal' RC plane.

Helping a novice to learn to fly without crashing can only be a good thing IMHO.

Last edited by JetPlaneFlyer; 10-01-2013 at 02:26 PM.
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Old 10-01-2013, 01:47 PM
  #11  
AEAJR
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RVDriver,

Welcome to Wattflyer and to RC flying. I know you are going to enjoy this. And the Delta Ray looks like a great starter plane.

If you want to understand batteries, motors and such I suggest you read through the chapters of this book that is posted right here on Wattflyer.

EVERYTHING YOU WANTED TO KNOW ABOUT ELECTRIC POWERED FLIGHT
http://www.wattflyer.com/forums/showthread.php?t=31071

Originally Posted by fhhuber View Post
Bad habits:

1) Hold the stick over in order to make a turn because the radio prevents a full roll from occurring and levels the plane when you let go.
This is a VERY bad habit to form. Proper turn procedure is to establish a bank angle and apply elevator to pull through, adjusting rudder stick to have the fuselage point just slightly inward from tangent to the arc of the turn. The Ailerons need to be returned to neutral or very nearly neutral during the turn then reversed to level the aircraft when the correct heading is reached.

Learning this bad habit will impede your learning to handle other aircraft.

2) the radio handling motor safety (somewhat) to teach you its safe to get your hand in the way of the prop(s)
This is even demonstrated in the video with the plane being handled in a blatantly unsafe manner.

Want me to go on?
Your comments are all correct, when operating under the guidance of an instructor who can recover the plane for the student when something bad happens. This allows the plane to survive those early mistakes so the learning goes on.

But this plane is designed to help someone learn to fly without an instructor. Since there is no one to recover the plane for the student, the plane recovers itself. The number 1 priority is to help the pilot and the plane survive the flight experience. Instead of a person on a buddy box you have a computer and a flight stabilization system.

This is no different from putting training wheels on my two wheeler when I was a child. Eventually they came off and I went to the next step. Meanwhile I enjoyed the experience and did not give up on bicycles.

I like the design of the system and have gotten feedback from those who have tried the SAFE technology. They feel is works well and accomplishes the mission for which hit was designed.

I have read comments like yours when I first started, 10 years ago.

* If you want to learn to fly you have to build a kit.
* RTFs, ARFs take away from the fun of the hobby
* 2 channel planes and 3 channel planes are a bad way to learn to fly.
* If you want to learn to fly you have to have an instructor.
* If you want to learn to fly you have to have 4 channels.

In the end it has all been proven untrue. Stable 2 and 3 channel planes made it easier for the pilot to learn on his own or to learn with a coach or instructor. Foam RTFs could survive the early crashes and be quickly fixed to get the pilot back into the air. And over time the flight assistance technology has gotten better and better and it is allowing more and more new pilots to be successful.

Taking the training wheels off always involves a next step in development when you realize that the plane will no longer recover for you. And, at that point you go that next step.

On this plane, taking the training aids off is done in two stages so the new pilot can test his skills a little at a time. You go from beginner to intermediate to experienced mode as you feel ready. But if you go to experience mode too soon, your plane does not have to die for your sins, you hit the panic button, climb to height and try again. This is like a flight simulator but in the real world. The plane has a reset button. I love it!

I would not be surprised to see many new pilots move through the three stages quickly. Some may get to experienced mode on the first day and stay there. Then they can use this plane to help friends learn to fly without having to watch their plane be destroyed.


Overall I like the design and the good feedback I have read and heard.

Last edited by AEAJR; 10-01-2013 at 05:40 PM.
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Old 10-01-2013, 05:36 PM
  #12  
RVDriver
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Default Thanks EAEJR

[QUOTE=AEAJR;925546]RVDriver,

Welcome to Wattflyer and to RC flying. I know you are going to enjoy this. And the Delta Ray looks like a great starter plane.

If you want to understand batteries, motors and such I suggest you read through the chapters of this book that is posted right here on Wattflyer.

EVERYTHING YOU WANTED TO KNOW ABOUT ELECTRIC POWERED FLIGHT
[COLOR= ]http://www.wattflyer.com/forums/showthread.php?t=31071[/COLOR]

Going out to buy a Delta Ray Hobby Zone is 45 min from Home!
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Old 10-01-2013, 07:32 PM
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Originally Posted by RVDriver View Post
Going out to buy a Delta Ray Hobby Zone is 45 min from Home!
Welcome to the hobby! Don't rush to get it in the air, wait for good calm conditions and make sure you understand how it all works and do all the checks advised in the manual such as balance point being correct and surfaces moving the correct way when you move the sticks.

All this stuff should be ok on a ready to fly model but always good practice to check.

Last edited by JetPlaneFlyer; 10-01-2013 at 08:55 PM.
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Old 10-01-2013, 08:42 PM
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Six Keys to Success for New Pilots
http://www.wattflyer.com/forums/showthread.php?t=18

> THINGS TO CHECK ON AN RTF

> http://www.wattflyer.com/forums/showthread.php?t=26372


HOW TO FIX WARPS, DENTS, TWISTS OR UNCRUNCH FOAM PARTShttp://www.wattflyer.com/forums/showthread.php?t=66805


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Old 10-02-2013, 12:43 AM
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Originally Posted by fhhuber View Post

How much extra you can carry varies greatly with what plane you are flying. Some planes can reasonably carry more than double their "ready to fly" weight as cargo or added battery capacity. You won't be doing any aerobatics with something loaded that heavy if you want to keep your wings attached though.
Yeah
A year or three ago, I put together a "G" meter that measured the g forces on a 65 inch wingspan model. In a simple loop, that G meter registered a peak of 9 G's! So, on an 8 pound model, that wing tube was subjected to over 70 pounds.

Something to consider when putting in heavier batteries on your model.
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Old 10-02-2013, 03:49 AM
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Before you try to fly make absolutely sure it's legal to do so where you're planning to go. I used to live in LA (San Fernando Valley (Tarzana), but same idiot laws) and park flyers were pretty much useless because it's illegal to fly them anywhere but an established RC club field. You can check Craigslist and find tons of them for sale in the LA area from folks who found that out. I know other places have similar restrictions on where you can fly RC models.
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Old 10-02-2013, 04:43 AM
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The anti-RC laws are generally the result of someone being inconsiderate in the manner they were flying.

Unfortunately easy to cause the laws to be written and very hard to get them overturned.
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Old 10-02-2013, 06:12 AM
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RVDriver
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Default How does Battery size to Motor size Amp wise

[QUOTE=RVDriver;925551]
Originally Posted by AEAJR View Post
RVDriver,

Welcome to Wattflyer and to RC flying. I know you are going to enjoy this. And the Delta Ray looks like a great starter plane.

If you want to understand batteries, motors and such I suggest you read through the chapters of this book that is posted right here on Wattflyer.

EVERYTHING YOU WANTED TO KNOW ABOUT ELECTRIC POWERED FLIGHT
[COLOR= ]http://www.wattflyer.com/forums/showthread.php?t=31071[/COLOR]

Going out to buy a Delta Ray Hobby Zone is 45 min from Home!
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Old 10-02-2013, 06:25 AM
  #19  
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Default How does Battery size to Motor size Amp wise

[QUOTE=RVDriver;925631]
Thanks guys, I went to Hobby Zone today, talked to "Dan" he explained Batterys/Motor Size etc, and he told me his experience with selling the Delta Ray, and customer feed back, that was all positive, so I bought one!

Now I have to assemble, charge battery's, and find a place to fly! Wife' sister and BIL have 40 acres just 50 miles north of us so maybe next week in the mean time there is a MARCEE Meeting next Monday.
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Old 10-02-2013, 01:52 PM
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What is a MARCEE?
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Old 10-02-2013, 04:28 PM
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http://www.marcee.org/
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Old 10-02-2013, 05:29 PM
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Oh, it is a club. Excellent!
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