WattFlyer RC Electric Flight Forums - Discuss radio control eflight

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x-nitro 03-04-2012 03:45 PM

new-be ??
 
hey guys and gals !! stay with me here { new-be} first thing , im a 20 yr veteran to r/c planes/heli's,,,but ALL nitro :blah:..i have a few questions on this battery stuff..im leaning towards the Great Planes Performance Series® Extra 300 SP ARF..ive done alot of internet reading on this plane and seems to be great..and alot of electric planes /motors/batteries..MOST planes only require ONE lipo batttery,,why does this set up require 2 ? can i do a one battery set up ? im also going with the hitec optic sport w 4-hs485 deluxe servos [always been a hitec fan] Never have had radio failure or n e thing !! im also wondering--the set up on the great planes page is callin for a 15x7 e prop ??
really ?? i really prefer tons of power vs alot of speed--15x6=14x6 ??
im also lookin at the blitz rc work G4 quad intelligent charger, just in case i HAVE to use 2 batteries :( thanks for ur time and help me ditch this nito @#$T !!!:D:D


xmech2k 03-04-2012 04:45 PM

Welcome to WF, x-nitro! I'm still somewhat new to this electron business myself, and some experts will hopefully help out here, but I'll give my thoughts for a starter.

Without digging into the instructions for the plane, I saw they are asking for 2 3-cell batts. My guess is they need them connected in series to up the voltage and get the required power from the motor. It may be possible to use a single 6-cell battery, but in rare cases, there might not be a space big enough for that.

Also, my rc plane experience is limited to foam, but I understand the wood built-up planes that are made for nitro power are considerably heavier than ones designed from the start for electric power. For this reason, you may want to look at some of those and compare.

Good luck!

fmw 03-04-2012 08:17 PM

I agree. It seems strange to me to want to do a conversion as your first electric. Check out 3D Hobby Shop. They have some Extras that should quell your appetite.

kyleservicetech 03-04-2012 08:47 PM

Giant Scale Electric Models
 

Originally Posted by x-nitro (Post 859921)
hey guys and gals !! stay with me here { new-be} first thing , im a 20 yr veteran to r/c planes/heli's,,,but ALL nitro :blah:..i have a few questions on this battery stuff..im leaning towards the Great Planes Performance Series® Extra 300 SP ARF..ive done alot of internet reading on this plane and seems to be great..and alot of electric planes /motors/batteries..MOST planes only require ONE lipo batttery,,why does this set up require 2 ? can i do a one battery set up ? im also going with the hitec optic sport w 4-hs485 deluxe servos [always been a hitec fan] Never have had radio failure or n e thing !! im also wondering--the set up on the great planes page is callin for a 15x7 e prop ??
really ?? i really prefer tons of power vs alot of speed--15x6=14x6 ??
im also lookin at the blitz rc work G4 quad intelligent charger, just in case i HAVE to use 2 batteries :( thanks for ur time and help me ditch this nito @#$T !!!:D:D


Yup, been there, done that. Giant scale electric conversion is fairly easy to do. But a warning here, it won't be cheap! Especially if you use name brand power equipment in your models. Electric motors tend to be able to swing big diameter propellers, notably larger in diameter than an equivalent glow engine. My Hacker A50-16S motor has a 16X12 prop on it that turns about 6700 RPM, pulling about 1100 Watts or so. That's installed in an 8 pound Showtime 50 that will fly straight up out of sight, and far outperforms a club members identical model with a four stroke 70 sized glow engine. Of course I get 6 minute flights with a three minute reserve. The glow engine can fly for near double that time.

On the other hand, since you have very little vibration in your models, your airplanes and its radio system will last a LOT longer. I'm still flying a model scratch built in 2002 that has well over 1000 flights on it, and actually had to replace the monocote covering because it got brittle from to much sun.

Another concern is the battery packs. For LiPo batteries, general opinion is they should be charged in periods of about an hour or so for best life for those $$$$ LiPos. I've been using A123 cells now for 5 flying seasons, and the first A123 battery pack has over 300 flights on it, with the same exact performance as when they were brand new five years ago.

These A123 cells are heavier by about 30% than a Lipo, and are also larger in physical size. On the other hand, they can be charged as fast as your charger can go. I charge my 12S2P (12 series 2 parallel) packs in about 20 minutes with a Cellpro Powerlab 8 Charger. Yeah it does get expensive. And you pretty much have to build up an A123 battery pack yourself.

Right now, I've got the Giant Scale Big Stick powered by a Hacker A60-16M motor, 12S2P A123 pack, 19X12 APC-E (Electric) prop that turns about 7000 RPM. That power system hauls that Big Stick straight up out of sight.

Take a look at what's involved:

Carl Goldburg Extra 330 Electric Conversion (This old model flew like a tank. Sold the model for $10, and glad to get it.)
http://www.wattflyer.com/forums/showthread.php?t=59273

Giant Scale electric motors vs Gasoline Engines
http://www.wattflyer.com/forums/showthread.php?t=58035

Great Planes Giant Big Stick Electric Conversion
http://www.wattflyer.com/forums/showthread.php?t=65052

Thread on 70 size glow engine conversion to electric
http://www.wattflyer.com/forums/showthread.php?t=45222

Hacker 6S2P A123 powered Models
http://www.wattflyer.com/forums/showthread.php?t=44686

x-nitro 03-04-2012 09:36 PM

thanks guys,but it NOT a conversion extra,,its sold arf-- gas/elec

xmech2k 03-04-2012 10:08 PM

Yeah, I was gonna say, not a conversion. But, being made for both nitro & elec, it will stil have the heavier structure required for nitro.

kyleservicetech 03-04-2012 10:09 PM


Originally Posted by x-nitro (Post 859964)
thanks guys,but it NOT a conversion extra,,its sold arf-- gas/elec

:oops: :oops: :oops:

Looked up your model, its a "Medium Scale" model with 55 inch wingspan. I'm an admitted Hacker nut, having 8 of them in my various models. They are more expensive, but these motors will perform per their specifications. IMHO, this size model is an excellent size to start off with as a first electric model. Cost is fairly reasonable, performance can be wild, and charging batteries is also reasonable. You will not be able to charge a pack for this type model from your auto battery though. It will require a deep cycle battery for the charger, unless you've got AC power available at your field.

My models have two of the A50-12S motors, and one A50-16S. The A50-12S motors are running with a 14X10 APC-E prop on a 6S2P A123 pack. The motor turns the prop at 7950 RPM. The A123 pack would be similar in performance to a 5S 4400 Mah (Milliampere Hour) LiPo pack.

This motor is somewhat more expensive than the Rimfire at $129, but IMHO in the larger models its well worth it. And should you have an issue with it (Like a really bad landing) service is available in the USA.

Just ran the numbers through a computer program www.motocalc.com (Free for 30 days then $39). Motocalc suggests a Hacker A50-12S motor, 14X7 prop, 6S1P 5000 Mah LiPo battery pack would be a very good combination. The motor will turn that prop at some 9500 RPM, and the power system will pull that model straight up at some 3000 feet per minute.

With the lower cost of an "Intermediate" sized model such as your Extra 300, one way to go would be to buy several battery packs so you can charge one pack while flying the other.

A good speed control is the Castle Creations ICE series, with a rating of about 80 Amperes. The CC ESC's also have a built in switching power supply type of BEC (Battery Elimination Circuit) so you don't need to worry about the receiver Nickel Hydride battery going flat. Long as you have power to the motor, you also have receiver power. These ESC's will cut power to the motor long before the motor battery is incapable of running the receiver and its servos.

Be sure to program a Castle Creations ESC for "Soft Power Down" of the motor on low battery. Also be sure to turn off the ESC brake on low thottle.

What you've got should fly very well, and very well might outperform a glow powered model of the same size. Most club members in my club have either gone to gasoline powered models 70 inches or larger, or to electrics in models smaller than this.

Funny, one old stand by member, now 76 years old was and is a diehard giant scale pilot with gasoline engines on the order of 50 cc and 120 cc twins. Didn't like electric power AT ALL! He's recently been seen with a couple of those little foamie jets, and having an absolute ball with them. This guy has had two midairs with his foamie, first one took 10 minutes with epoxy, second mid air, he picked it up and flew it again.

x-nitro 03-05-2012 11:54 PM

after two days of internet shoppin :D:D i think im gonna go with the extreme flight extra !! plane/mtr/ESC= 299.00 vids look wicked !!! and it only weights
2.5 lbs vs 6-7 lbs !! and it takes one 4-S bat NOT 2-6s :tc:

xmech2k 03-06-2012 01:40 AM

Good choice. I've seen some at the field and they are great performance.

x-nitro 03-06-2012 01:47 PM

mind change
 
had to go fartin around AGAIN !! i like the looks of the extreme EDGE-540
good-er !! same size-components and flight characteristics !! but ive always been a BIG fan on some yellow color for orientation purposes !!!!
ive buried a FEW from == dam,,,,i thought it was inverted !!! :sad:

mred 03-09-2012 08:46 PM

You can almost always go with a 6S battery instead of 2 3S batteries, but here is the problem in doing that. Once you buy that 6S battery, you have a 6S battery and nothing else. Now with 2 3S batteries, you have 2 batteries and can break it down and use a single 3S on a plane without buying another battery. That is why most people go for the smaller batteries and hook them up in series. You can always break a pack down made up of smaller batteries, but you can't break a 6S down for a smaller plane.

As for charging time of LiPo's and 123 cells, there is not that much difference now with the new batteries. You can get up to 65C LiPo's now and that makes changing much faster if that is your thing. I don't really care about charging mine in 15 minuets, so it doesn't bother me to charge for an hour. 123 cells are just to heavy for some plane I fly and that leaves LiPo's as pretty much the only battery. Bigger planes can handle the extra weight fine, but to my way of thinking, I would rather have all LiPo's and change them all the same way then have to worry about getting the charge wrong for a battery and having a problem.

If you are new to electric flying, then you may want to go here and read up on electric power and everything else concerning electric planes. You can skip over some of it, but there is a lot of good information in here.
http://www.wattflyer.com/forums/showthread.php?t=31368
That should answer most of your questions and if you still have some, you can ask there or in another post and get the answers you are looking for. The one thing you will need if you don't already have one is a watt meter. That is a must have item if you are going to be flying electric planes.

Ed

Weekend Flyer 03-15-2012 05:06 AM

mred makes some good points. Having 2 x 3S batteries give you more options. You can always use them in other planes too.


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