old bird

Bob, make a plug and move the step back 1", no more porpoising.

Best regards from old bird.

Bob93447

Did it work for you? As I remember you made several passes at extending the step.

Bob

old bird

Bob, yes it did work. I had many successful flights after settling on the 1" figure. I first tried 3" and that resulted in a stable speedboat that would not rotate and get off the water. Another poster here tried 4" and 2" if I remember correctly, and that did not work either. One inch was the magic number. Also made extended tip floats to keep the wings from diving into the water, as others have posted. I have since seen other solutions including a successful electric version and one powered by a YS 4-stroke. Both of these of course allowed the builders to get some weight out of the pylon, fuel and batteries down in the hull. Moving the step back has been used to solve porpoising problems in full-scale aviation, most notably in the Boeing 314 China Clipper. In a book I read about this beautiful plane the first few planes had dangerous porpoising issues which were solved by building and attaching a wooded plug behind the step!

I flew my Seawind for two full float fly seasons and then was glad to sell it. It took 100 yds or longer to take-off at our altitude of 5500 ft. with an OS 91 two stroke screaming its guts out. I figured the wing loading once and it was over 40 ounces per square foot! Once in the air it flew fine and was very fast for a seaplane and looked very cool if you like the modern style in airplanes.

The full scale Seawind also had water handling problems I have read. The last I heard they are all grounded after killing a couple of pilots, I would like to hear the details on those incidents. Perhaps the GP version is TOO scale?

I am now happily flying a kit-built Seamaster and a Goldberg Cub on floats, and having nice lazy days at the lake. That was what I wanted out of float flying and I never got that when flying the Seawind. I was happy to take $75 for it and you couldn't give me another one.

Best regards from old bird.

Bob93447

Old Bird,

Can I assume that when you say make a 1" plug you mean a 1" extension of the hull? Did you use foam or balsa fiberglassed? This certainly seems like one of the nicest solutions to date. I totally agree that this is not a relaxing airplane to fly, especially at altitude. It would have been a great plane is GP had made it about 3 lbs lighter or if they had added 30% more wing at the same weight. Right now its more of an obsession than a hobby as I try to get it right. You certainly went through your battles with this plane to get it right.

For relaxed water flying I am now using a Seawind EP and a Polaris XL. Are the Reno guys still using the Res. off I-80?

Bob

HUNTERANDJEFF

Oh, my ears are hot lol! Someone mention me
Ok, I tried the step extention too. At 3" the plane couldn't rotate. Yes, that is true. At 1", the plane rotated and it helped with the porpoising but not much. What really helped were the aileron stock back from the step. Do not attatch them permanently, just put them on as I did so if you don't like them, you can take them off. Also, the "V" hull doesn't help any at all with that porpoising. It makes it easier for the front end to dig into the water and then it pops back up like a cork. Do you see flat bottom john boats and seamasters porpoise? The "V" hull helps with big waves though but I wouldn't fly in those conditions anyway lol!
J

old bird

Bob, the plug was made of foam, glued to the hull behind the step so as to extend it 1". Then I glassed it and painted it white.

Yes, the Reno RC club flies at Boca every Wednesday, we have a great time and usually make a picnic out of it around noon. I hear you about the obsession with the Sea*****, I just couldn't let it beat me so we kept trying. Good luck with yours.

Hunter and Jeff, sorry the step mod didn't work out for you but it sounds like you came up with a different solution so OK. I think the Seawind came in at least two different weights, some had to add a lot of weight to the nose and some did not, might explain the different results that have come in. If I remember correctly, I added about 8 ounces of lead shot to the nose of mine so the CG would come out right.

Best regards from old bird.

old bird

Bob, the plug was made of foam, glued to the hull behind the step so as to extend it 1". Then I glassed it and painted it white.

Yes, the Reno RC club flies at Boca every Wednesday, we have a great time and usually make a picnic out of it around noon. I hear you about the obsession with the Sea*****, I just couldn't let it beat me so we kept trying. Good luck with yours.

Hunter and Jeff, sorry the step mod didn't work out for you but it sounds like you came up with a different solution so OK. I think the Seawind came in at least two different weights, some had to add a lot of weight to the nose and some did not, might explain the different results that have come in. If I remember correctly, I added about 8 ounces of lead shot to the nose of mine so the CG would come out right.

Best regards from old bird.

ALO 111

I fly the nitro planes version but most things seem pretty much the same. Also using a Os 91 fs that always seems to overheat but is really fast. Still needs a lot of space to get off the water ( the method i use has been mentioned here)
I really am not a electric fan but if funds permit i will make this plane electric it will shed so much weight. The lighter electric motor at the back and no fuel behind cg will mean tacking out my old gym weights from the nose and replacing them with the lipo,s
Its got to work, just need to covince the wife why i need a visit to the hobby shop.

Cyntec

Hi There!

I just pulled my seawind out of the box and started building it (finally). I think it's one of the original versions GP came out with so I'm wondering what tweeks I should be making to the plane that will make it perform better (smoother), be more durable and sturdy than it would be if I follow the instructions in the manual to the letter. I started going through all the posts in this thread to see everyones' suggestions but I just realized there are 1,255 posts! If I go through all of them it'll be next summer before the plane is built. If anyone has any tips or advice on building the seawind please let me know.

I'm using a 2-stroke OS MAX 65AX engine and a 3-blade Master Airscrew 11x7 in. - 28x18 cm prop.

PS. At the beginning of this thread people were saying that the Seawind CAN'T have landing gear if I intend to fly it on water. Has anyone figured out how to have the landing gear installed and still land in water? I have E-Flight electric retracts.

Square Nozzle

My Feedback: (1)

I recently purchased a GP Seawind from a friend. The plane has a Magnum .91 on it so I'm sticking with that engine for now. A Saito may be in it's future. What I need from the experienced Seawind flyers is the takeoff technique. On my first flight the take off consisted of a series of water (ground) loops until the plane gained speed and finally got itself straight and took off. The flight was exilerating with a little aileron trim. The landing with full flaps, a piece of cake. Again, the takeoff leaves a lot to be desired. I've read and heard diffenent methods of getting off the water without the on water acrobatics. Some say easy on the throttle. Others say full throttle from the start. I've heard "don't touch the rudder", "full up elevator", move the CG, change the thrust line and on and on. What works?

jrf

My Feedback: (551)

Square:

You have already read all of the advice, conflicting and otherwise, so simply repeating it is not going to help you. Clear your mind and think about the configuration of the Seawind. The engine is mounted way up high, so the thrust line is 4 or 5 inches above the point of maximum drag, which is the water. What happens when you give it full throttle from rest? The thrust tries to push the nose down into the water. The Seawind has a nice wide, buoyant fuselage, so the water pushes back and the porpoising starts. If you accelerate slowly, at least until the Seawind is up on a plane, the thrust is more closely matched to the drag and the airplane will not porpoise.

The tip floats are pretty small and pretty high off the water. If a cross wind makes a wing drop during takeoff, the tip float does not have the size, shape and buoyancy to keep it from digging in, and a water loop can be the result. This tendancy is minimized if you take off directly into the wind. (See the next item also.) Some people have added extensions to the tip floats and that does help, although it looks a lot like training wheels.

The water rudder is huge and extremely effective once the speed picks up on the water. Just a touch of rudder at takeoff speeds will cause the Seawind to water loop. No fullscale airplane has the water rudder in the water during takeoff. Many of us have cut the water rudder in half. I removed mine conpletely. Basically, you must not touch the rudder stick during takeoff. That is another reason why you have to take off directly into the wind.

Based on your discription of your takeoff, I suspect the water rudder is your problem.

Jim

EDIT: I forgot to mention the flaps. 50% for takeoff, 100% for landing. Only a small amount of up elevator is reqired for takeoff, and as ALO 111 says, the Seawind will usually take off by itself when it reaches flying speed.

ALO 111

Jrf has basicly told you all you need to know about take off and i cant agree more. I also dont use a water rudder,full up elevator at very start with slow throttle advance until planning speed . Keep wings level while speed builds she will normaly lift off on her own or with a small bit of up ele . Needs a lot of speed on take off, you can see how this fits in with what Jrf explained about motor location ect. Good luck,have fun .

Square Nozzle

My Feedback: (1)

Thank You guys. What you have explained makes perfect sense. I was considering putting a gyro on the rudder to keep the plane straight but maybe the aileron is a better place for the gyro. It can certainly act faster than I can to keep the wings level.

jrf

My Feedback: (551)

I don't think the gyro on the rudder would solve your problem. Any input you make from the stick will override the gyro so if you touch the rudder stick the gyro will not correct for you. And if you don't touch the rudder stick you don't need the gyro. To be clear, the air rudder is not a problem. Even though it looks huge, it is not overly effective. If you remove the water rudder, the water looping problem will go away and you can still steer fairly well on the water with the air rudder.

I don't thnk the gyro on the ailerons would help either, because the ailerons are small and the low airspeed during the take off would make the gyro ineffective until about halfway through the takeoff run. But I don't think it would hurt. Warning; put it on a switch so that it doesn't cause strange effects during normal flight.

Eliminate the water rudder, takeoff directly into the wind, accelerate slowly and level the wings with the aileron stick. You won't have any problems.

Jim

Square Nozzle

My Feedback: (1)

Thanks Jim, I'm going to do what you suggest. I'll post results when I get back to the water.

ALO 111

You have got me wishing winter away so i can fly mine again. Still to dam cold

Square Nozzle

My Feedback: (1)

ALO 111. We're moving towards Fall so your spring is just around the corner. Hang in there. It won't be long and you'll be flying again and we'll be wishing the winter away.

ALO 111

Yup i cant wait its been a long winter and very dry year, my dam is almost empty hope we have good rain soon. Here is a pic of my dam when full.

Square Nozzle

My Feedback: (1)

ALO 111, that is a beautiful, no- stunning picture. We,re in the late summer cool down phase just before Fall. We've been fortunate up here on the top of the world. Sufficient rain to keep lakes full. By the way, I've always wondered how to you people stay on the bottom of the earth? Being on top it's not a problem.

ALO 111

How come all the water does not run down hill to us ?

Square Nozzle

My Feedback: (1)

Jim and ALO 111, I flew the Seawind today. A beautiful, light wind, sunny and warm day (sorry ALO 111, your days are coming soon). Anyway, I followed your instructions to the letter after having trimmed the water rudder size way down to about 1" in blade axial length. The plane had a slight drift to the right which I believe may be the result of the rudder not being perfectly straight. At any rate, no water loops and a nice smooth takeoff. Thanks guys for the advice. I was thrilled.

ALO 111

Great stuff well done, how was your landing? i still need to work on mine.

Square Nozzle

My Feedback: (1)

The landing left a lot to be desired. I was getting to close to the beach and literally forced the plane onto the water. Bad thing to do. Several bounces untill it finally stopped. Actually my first landing with the plane before I modified the rudder and followed your instructions was a beauty. I made the approach with full flaps and literally tried to keep the plane from landing just a foot or so off the water. Once it ran out of flying speed it settled onto the water very nicely. I can hardley wait to get back to the lake.

ALO 111

There is a good South Africa expression to express the fun you are having " LEKKER" its Afrikaans for everything that is fun,pleasant exciting basically "all good"
So have a "LEKKER TIME" next time at the lake.

Bob93447

It's summer in the Southern Hemisphere. Why haven't we heard from the Seawind flyers down under?