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Old Jul 14, 2010, 11:54 AM
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United States, CA, Shingle Springs
Joined Jul 2007
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Same here. Mine is stock and it has plenty of power. Take off only takes 20 feet or so and it will climb at a very steep angle with full power. I'm not sure more power is better for this plane due to the high thrust line and the tendency for power to push the nose down.
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Old Jul 14, 2010, 02:26 PM
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Estevan Sk
Joined Apr 2008
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Catapult

Has anyone used a catapult for taking off of grass? I use grass strip and my seawind will lift off but it is a struggle. Was wondering if a bungee system would be any help or do I go to a larger motor? At present using a Turnigy 2213/20
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Old Jul 15, 2010, 12:35 AM
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Joined Jan 2009
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Thanks for the motor responses, folks. Given that, and the way the motor mount is heavily customized for the 28-30-950 Rimfire, might as well give in. Though I had to undo a shaft reversal from the previous deployment of that motor. No biggie.

Fairly straightforward build, so far... looks like final AUW will be right in the ballpark, around 23 oz. or so with 3S/1800.
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Old Jul 15, 2010, 02:58 PM
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Quote:
Originally Posted by patchman61 View Post
Has anyone used a catapult for taking off of grass? I use grass strip and my seawind will lift off but it is a struggle. Was wondering if a bungee system would be any help or do I go to a larger motor? At present using a Turnigy 2213/20
I've not tried a catapult, but taking off the grass I usually have to go to full power and give the plane a push to get it going, then keep full up elevator until it builds some speed. I have found that the grass needs to be fairly short and smooth or it is difficult to get it going. The high thrust line pushes the nose into the grass until it gets some speed. The up-thrust mod discussed here would probably help the grass take-off performance.

The Turnigy motor you are using has a similar kV and watt output, so it sounds like it should perform close to the stock Rimfire. What prop are you using with it?
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Old Jul 15, 2010, 06:44 PM
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Estevan Sk
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The prop is an E-Flite 8 x 6E slow flyer prop. (EFLP08060) The original met with a mishap. I shimed the bootm of my motor mount to give some upward thrust but have not flown it yet. On the bench I noted that the downward motion of the motor has disappeared.
Thanks
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Old Jul 15, 2010, 10:14 PM
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United States, TX, Midland
Joined Feb 2009
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Pendulum effect while banking

Back on post #1527 I described a problem I had with my seawind violently banking from one side to the other. In that post I refered a loop around the field. I think some of the responses that I have read assume that I was doing a loop. I should have used another term describing the attitude of the airplane. The airplane was flying level. I had just come out of a banking turn after taking off. I gave it some opposite aileron to level the wings as I normaly would but the would not stop rotating. When I tried to correct it, the wing flopped back the other way very quickly. Now I have slapped the airlerons from side to side before on other ariplanes to acheive quick response in a roll, but this did not look any thing like that. The only way I could imagine that the roll characteristics would act like that is if the weight of the engine pod was pulling airplane over.

This post may or may not clarify my earlier post. But, If anyone has had a similar experience and/or has a solution or cause, please let me know.
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Old Jul 15, 2010, 10:40 PM
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United States, TX, Fort Worth
Joined Jun 2000
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Quote:
Originally Posted by rafe_b View Post
Hey gang, I received my Seawind EP ARF yesterday and considering what to do about the motor. I actually have the recommended Rimfire motor (28-30-950) on hand, but in my humble opinion, this motor feels too small for a plane with an AUW of 24-26 oz.

Forgive me for not reading the whole thread. What's the consensus on using the stock motor? Left to my own hunches, I'd use something like the headsuprc 3530-11 -- something around 250 watts (continuous.) On the other hand, prop size is probably limited to 8 or 9 inches, so maybe a slightly higher Kv is called for (assuming 3S Lipo for power.)
Ditto that the stock suggested motor is plenty of power. I used an equivalent BP motor and it worked like a champ.

If you overpower the Seawind, it makes the high thrust line full throttle low airspeeds issues a good bit more annoying.
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Old Jul 15, 2010, 10:42 PM
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Re post 1527....Adverse yaw?

Hi tsudduth,

Hello mate, it sounds what you describe, to me, is an effect known as "Adverse Yaw". Look here, for one description;
http://www.aerospaceweb.org/question...s/q0135a.shtml

I would check that the Ailerons move as per the set up instructions, range of movement and diferential, more up than down movement.
Check that your rudder is working in the correct direction, and you do use it in the turn?
I take it when you say "loop" around the field, you are flying a circuit or pattern around the field, I would think this is the cause as you have the c/g correct and your aeroplane comes out of a mould and this is not mentioned by other guys,..hope this helps you, happy flying, cheers,

regards to all, Al
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Old Jul 16, 2010, 01:15 AM
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Joined Jun 2000
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tsudduth,

I will come out of the closet here and say that my seawind has similar behaviour. I made a similar post a while back. Checked the balance (back on the spars) and have tried different packs. Sometimes I have to be really quick on the ailerons to keep her upright, giving the feeling that the machine is not very precise.

The one thing that other posters have mentioned are binding ailerons, and I can see how this may cause the roll problems. I make sure the torque rods are well lubed with CX and are free, particularly after a salty fly, but the behavior is still there on both my seawinds.

I'd be really curious as see how long others can fly their seawind "thumbs off" straight wiithout her rolling over onto her back?
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Old Jul 16, 2010, 07:32 AM
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United States, TX, Kingsland
Joined Sep 2005
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Quote:
Originally Posted by patchman61 View Post
The prop is an E-Flite 8 x 6E slow flyer prop. (EFLP08060) The original met with a mishap. I shimed the bootm of my motor mount to give some upward thrust but have not flown it yet. On the bench I noted that the downward motion of the motor has disappeared.
Thanks
Be careful changing the thrust angle very much. You will find that you will need to add elevator trim to get level flight under power and the plane will dive or climb when you remove power to land.
McD
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Old Jul 16, 2010, 10:39 AM
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The thrust vectoring got me thinking, as I had the same problem.

Since I was NOT using the stock Rimfire motor and a Turnigy motor, I decided to pull off the cowling and have a look.

What I found that since the Turnigy was a 4 point mount, that the bottom tab was not really attached to anything. The end result was that that motor had some downthrust.

I'm just fixing that now to shim the motor back into the right position. I'm sure that that 'power up' 'dive down' effect will go away once I get her back together.

Mike
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Old Jul 16, 2010, 10:47 AM
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Originally Posted by jlorenco View Post

I have my tips trimmed and it works great. I even touhed down with a wingtip at the same time the fuse touched and it had no inclination to water loop.

I does seem that you have to totally grease the landing to keep it from skipping. I only get a couple of those in probably every 10 landings. I think this plane will make me much better at landings though.
I trimmed the tips on my first one, and then immediately regretted it.

With the wind about 5kph or so, I was doing a turn from downwind to upwind while on the water, and the lack of buoyancy resulted in the bird rolling over and turtling. Until I build in the un-turtle feature , I would rather have the extra buoyancy on the wing tips.

The tips do catch as I get up on the step, so I have learned to add some aileron to counteract the torque from the thrust. Then, when on the step, she runs just fine.

What works for landing on me is at 'that point' that she is just about stalling, and about 2" above the water, I cut the throttle a bit and flair. This sticks the stern in the water first and results in a nice landing. However, if there are any waves at all, it gets tougher.

Mike
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Old Jul 16, 2010, 12:35 PM
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Joined Sep 2006
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Alternate Motor

After frying my 140w motor from BP hobbies, I decided I needed a replacement with a bit higher wattage rating yet something more affordable than the rimfire suggested. I chose the Supertigre .10, also from Tower, with a wattage rating of 310. Since I had already chopped off the included motor mount, mounting the Supertigre was not a problem. It works great, giving about 185 watts peak using an 8x6 apc. Performace is great; plenty of power to get off the lake at 6200' elevation and to do basic aerobatics. Straight and level flying can be accomplished at less than 50% throttle and the 1600 mah zippy batteries I use can give more than 15 minutes of relaxed flying.
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Old Jul 16, 2010, 04:16 PM
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United States, CA, Shingle Springs
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Originally Posted by Tooly View Post
tsudduth,

I will come out of the closet here and say that my seawind has similar behaviour. I made a similar post a while back. Checked the balance (back on the spars) and have tried different packs. Sometimes I have to be really quick on the ailerons to keep her upright, giving the feeling that the machine is not very precise.

The one thing that other posters have mentioned are binding ailerons, and I can see how this may cause the roll problems. I make sure the torque rods are well lubed with CX and are free, particularly after a salty fly, but the behavior is still there on both my seawinds.

I'd be really curious as see how long others can fly their seawind "thumbs off" straight wiithout her rolling over onto her back?
I highly suspect you are getting some kind of binding on the ailerons because my Seawind and another here locally do not have any tendency to be unstable in roll. My Seawind flies very stable and smooth in the air. If you look back at post #1507, I posted a picture of my wing with the plywood wing mount attached (after it fell off ). You can see how seriously bent the aileron pushrods are the way Great Planes assembles it. The aileron design for the Seawind is lacking and lends its self to binding and poor centering from all the friction.

Sometimes I forget to start my timer so I have to look at it while I'm flying. In these cases, I just get the plane straight and level, then look down at the timer, hands off. It takes me a few seconds because my eyes aren't what they used to be, but when I look back the plane is still flying nice and level.
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Old Jul 16, 2010, 04:17 PM
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United States, CA, Shingle Springs
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Mike[/QUOTE]
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