noddy181

Alo

I will send one thru later, I am working late with stocktake.

Mark

Bob93447

Mark,

I found a conversion factor on RC Groups that says multiply the displacement of your glow engine by 2000 to get the watts required to fly electrically. So if the new Northstar is about the same size as the one you are flying on the TT .36, then we're looking at a 720 watt (roughly 1hp) motor. Does this sound about right to you?

How much weight have you allowed for the motor and battery in your setup? Remember that you can get you control power from the flight battery.

Bob

ALO 111

Thanx Mark

Bob93447

Mark,

After researching the power system for your 90% Northstar, I've decided that this looks like a really interesting project. You seem to be right in the "sweet spot" for electric power. You might want to consider starting a separate thread with pictures and plans.

Using the rule of thumb for power that I put in the last post, I started looking at HC for 700+/- watt motors and supporting power.

1- Motor Turnigy sk 35-48-1100. Weighs 171 gms and costs $19.71 But in reading the reviews, it seems to have quality issues, so you might want to consider
1A- Alternate motor Scorpion Sii-3020-1110 Costs about $65 but weighs less.

2- Motor contoller and power supply Turnigy Plus ESC, good for 60 amps and provides 5v @3amps for receiver and servos. $34.5 and 60 gms.

3 - Battery Zippy 4 cell (14.8 v) 3000 mah, 20C for $17 and 300 gms.

4 Prop = GWS 3blade 9x5x3, 2 for $3.

If you go to the Castle Creations site, you can model this setup using the Scorpion motor and a Phoenix 60 amp controller. It shows about 90 OZ of thrust at sealevel. Should be enough to drive the 90% NS like a pocket rocket. For more speed you could use a 3-blade GWS 9x7x3 but it will overload the motor if used for anything but short bursts.

Bob

alcarafa

Thanks for your reply Bob , I will consider the upgrade you mention, hobbyking motors are not the best quality , but esc's are good tough!!

Bob93447

Rafa,

Good luck with your Seawind. Let us know what power system you use and how well it performs. Please check carefully to make sure that your motor has at least a few degrees of downthrust (certainly no upthrust). And if you check through this thread (and the Seawind thread on RC Groups) that the electric seawind needs to have the CG much further back than the nitro powered version to compensate for the fact that there is no fuel burn.

Bob

noddy181

Hi Bob

Thanks for the detailed reply, I already have quite a few packs, including 2 x 3000 mah 4s packs not yet used, a turnigy plush 60A speedy and the 35/48 1100kv motor, used it in my Eflite Ultra stick 25 e on floats, no issues with quality, i note HC sells 3 blade e props quite reasonable $.
I will let you know how the build goes.

Thanks

Mark

marcoferretti

Hi all, I went through the entire thread: thanks for sharing your experience with this beautiful ship!
I'm about to order a Seawing at my LHS... no fear in taking-off/flying/landing heavy wingload planes, but my question is: according to you, do you suggest this as a first seaplane?
Thanks!
Marco

HUNTERANDJEFF

No, absolutely not.
The SeaMaster is prob the best 1st seaplane to fly if you have rc experience. It is really easy to fly. It takes off and lands like a butterfly and can be fast and manuverable too.
The Seawind is "tricky" to say the least but is beautiful in the air and fast.
Jeff

Bob93447

Marco,

The Seawind is definitely not recommended as the first "waterplane". That said, you can probably pull it off if you are a very experienced flyer and have access to a large, very smooth lake and have a good retrevial boat available. I flew the Seawind as my first waterplane. I did cheat a bit, my first flights were off of snow. I also went electric and avoided the problem of the cg changing as fuel is used. But even today I am not entirely comfortable with the plane and only fly it early in the morning when I can get a friend to take me out in a boat early in the morning when the lake is smooth. Whatever you do, do not underpower it. The biggest problem with the seawind is getting it off the water. I am currently in the process of upgrading mine from 1000 watts of input power to nearly 1800 watts.
If I were to do it again, I would start with the Seawind EP, the foam version that only weighs about 2 lbs. I have one now that I fly more regularly than the big Seawind. It is more durable, easily repaired, and has some of the flight characteristics of the big one. The biggest issue with the seawind(s) is that you cannot apply a burst of power near the ground (or water); if you do, the nose will dip and you will immediately find contact with the surface. Seawinds also tend to propoise on takeoff; usually by the third bounce they have enough altitude to bury the nose if the plane hits the water again. You can see that problem in the Great Planes promotional video and videos found on U-tube and RCGroups. The big Seawind definitely has this problem, much more so than the foam version with its lighter wing loading.



Good luck,
Bob

marcoferretti

Bob, Jeff, thanks for your comments.
You have summarized in simple words all the water handling issues of the seawind; still I'm not demotivated!
At my local club, we arrange for a copuple of "flying days at the lake" every year, just because we need to borrow or rent a boat for retrieval. Lake is very large (almost 0.8 miles wide) and it is surrounded by tall mountains on one side and slight hills all around, so water is mostly flat
This said, I will fly it from grass at our field most of the time, but i think it's a very challenging thing taking this bird off water, I have to try!
So, I think I will order my seawind, and meanwhile I'll put on floats my old Spacewalker...
Marco

Bob93447

Marco,

I assume that when you say that you are going to fly your Seawind off of grass that you are going to put wheels on it. Flying off of grass with just the hull (no wheels) may result in damage to the hull. I quite flying my big seawind off of hard snow because of hull damage issues. Also, make sure you remove the water rudder; it sticks way out and is very vulnerable to damage.
Overcontrol with the rudder is probably the biggest problem that most people have with the seawind. I set mine up with a dual rate transmitter so that on takeoff, I have relatively high rates for everything but the rudder its set for 10%. After takeoff I switch to flying rates that have normal rudder control. The other option is to cut down the size of the water rudder to make it less sensitive. Most of the problems that you see on videos of the seawind are when the rudder is moved too much on takeoff one of the tips digs in and takeoff is aborted.

Good luck and keep us posted on your progress,

Bob

marcoferretti

Bob,
In some previuos posts I found out you went electric on your Seawind.
I must say that I am a 4-stroke lover, I just the way they perform and their sound is beautiful! But please, convince me going electric on my seawind!! I mean.... pros&cons...
Thanks!
Marco

Bob93447

Marco,

I tried to send you an extensive eval of electric vs. glow but the message timed out and didn't get posted. Send me your e-mail address via the PM route and I will send you the detailed analysis. A quick summary though;

Pro
Weight Most of the Nitro powered seawinds weigh in at > 11 lbs, nearly 12 when fueled because they need 1-2 lbs of ballast to get the cg right. Mine weighs in at 9.5 lbs with the batteries installed.

Vertical CG The Nitro powered version has > 1kg of motor, fuel, and servo on the pylon. All of this weight is above the vertical cg which helps the wingtips dig in on takeoff, often causing an aborted takeoff attempt. An electric motor of 2000 watts power is only about 300 gms. I am convinced that this is the reason, as a first time seaplane flyer, that I was able to get the seawind in the air off of water.

Con
Expense of getting into big electrics. I will detail a setup that is cheaper than a new 4-stroke in my e-mail back to you.
Lack of noise can't hear a thing when it is >100 meters away.

When you send me you e-mail address, let me know the altitude of you lake. It makes a difference. I'm flying at >2000 meters.

Regards,

Bob

marcoferretti

Bob,
PM sent.
forgot to tell you: my lake is about 300 meteres above sea level. What difference does it make?

Marco

jet22b

Hey Guys;
This is some sad new to hear about the Great Plane Seawind. See link below!!
http://www3.towerhobbies.com/cgi-bin...&I=LXKEW6&P=ML
Went to Tower website to buy one more SeaWind for my hangar and saw the bad news. Then I went to Great Planes website to see what was up and I hit the online buy and it took me back to Tower and the same bad news. No more Great Plane Seawind!![&o][&o] Oh well, I will still have fun with the one I have!! I must say, this is a sweet flying plane on and off water!!!

Sonny
aka
jet22b

ALO 111

Guys dont be to scared of the Nitro Planes Seawind It also has some weak points but it is also better than the Great planes model in other areas. Also a lot cheaper !
I have a lot of experience with the Nitro Model and will gladly share what I have learned.

nilsreinert123

i have a nitroplanes seawind which i have used a lot of time on modifying , but have not flown it yet , looks forward to the summer!!
I have built a new cockpit in foam covered with film and rubber seal on the edges , also where the wings meets the fuse to make it as waterproof as possible . I have buildt the wingservos completely into the wing front area. all the other servos in the front using goldnrods. i have a os 75 ax two stroke on it. i have balnced it at about 2 cm from LE ,dry.

Do you have som hints for me to have a successful first flight ?

marcoferretti

Hi all! Finally my seawind arrived last friday.
I saw the bad news on TowerHobbies.... wow, seems like I'm lucky!

I'll go electric on my seawind - Bob, thank you so muck for your suggestions!

And some mods will be done too.

I don't like having small servos on rudder and elevator. Small servos have small gear and a small potentiometer. Since I have no fuel-tank, the elevator servo will be placed in the tank compartment. The rudder servo is placed in the fuse. Hope all this will help shifting the weight as forward as possible. Notice the added formes for the battery tray.

That's all for now.

Marco

ALO 111

The Seawind flys on rails once shes up to speed. Its the take off and landings that are a challenge. I seem to have the take off sorted now,i think,i hope.
I dont use a water rudder,give full up elevator and slowly increase power while keeping the wings level as she gets up onto the plane you keep increasing power while decreasing up elevator. When done right she will pick up speed without porposing,just need to make sure she does not take off to soon. Altough mine is so heavy she needs a lot of speed before she lifts off. Climb out slowly until airspeed is up,real scale like . landings are still a bit of a challenge to me but I can only advise you what I was told by someone who has his landings sorted. land with full flaps and try to keep her just off the water until the speed is way down. basically you need to flare her in big time just just off the water to land at the slowist speed possible. This will stop her bouncing on landing he tells me. I am still learning this as mine almost always bounces and then splashes down.
Good luck and enjoy its good fun to have planes that are a challenge to fly as well as easy ones.
keep an eye out for weakness around the vertical stabilizer and the fibre behind the engine. I have had to brace mine in this area.

obiwan12

My Feedback: (9)

As of 11:00 am est, tower has a few back in stock.

jet22b

Maybe Great Planes will keep making this ARF. It is one sweet flying bird on and off the water. Just pull my Seawind and it is sitting on the work table to be check over and make ready for this year. Thanks for the info, I just may pick one up before Great Plane plug the plug on this great ARF!!!

Sonny
aka
jet22b

itsevlam

same problem. ordered replacement cowl.

itsevlam

shame on yoy....leaving battery in plane when not in use

marcoferretti

Little progress on my seawind.
I have installed the nose retract. It's a mechanical retract, but instead of the servo, it will be operated by a small air cylinder (air up - spring down) that was placed inside the fuse. It took some time to find the right position and fine-tune the lenght and shape of the pushrod, but now it works fine.
Next, I have to find a place for the steering servo.
M.