Since I can't find an actual assembly thread on the Seagull Extra 300 - 75, I'll just start one. What I can find is old.

Mine arrived yesterday from Horizon Hobby, very fast shipping. I'm very impressed with the Seagull Extra 300 - 75. Looks very good, I'm not sure why they call it a .75 though, looks like a .60 to me.

This is the equipment I intend to use.

Futaba 7C 2.4 w/617 reciever.
Futaba 3004 servos on the ailerons and elevator.
Futaba 3003 servo on the throttle.
Dymond D5000 High Torque Metal gear on the rudder.
6v NiMH 2200mah battery.

Tower .75 w/Bisson pits muffler. (because I already have it.)

Radio gear will all be new.

Most of the hardware that comes with the plane looks ok but I will upgrade some of it. The fueltank, landing gear, control horns, and hinges. I may replace some other parts as I get into the assembly.
I will use Robart hinges and control horns. A Dubro Super Strength landing gear because it looks better and I have yet to bend or break one.

More pictures.

I got started tonite with the ailerons. I wanted to replace the fibre hinges with Robart hinge points. I laid out the locations on the first aileron then moved on to the wing panel. Thats when I realized the trailing edge was not thick enough to support the hinge points, they were only 1/4" thick.
I didn't like the fibre hinges so I upgraded them to Great Planes fibre hinges, they were nearly twice the thickness of the supplied hinges.

Here are some photos of the Robart hinge point instalation if anybody is interested in how to do it.
Two things you must remember. The hinge pin must be in line with the leading edge of the aileron, and the hinge point must be at 90 deg. to the aileron.
When you glue them in put alittle vaseline on the pivot point to keep the epoxy from sticking to it. Also, use 30 min. epoxy to give yourself time to work. Work some epoxy into the hole thenremember to "butter" the hinge before you insert it into the hole.
Needless to say, I did the work for nothing anyway.

I then moved on to cutting the stripes I want to do on the bottom of the wing, need something to make that white wing stand out against the sky.

I didn't get to spend alot time on it tonite, had to spend some quality time with the wife.

I did get the red stripes laid out and put on the wing and the stab. I also got the servos installed in the wing panels.

Flying time tomorrow so no more work until tomorrow nite.

Last nite I worked on the engine mount. I want to mount the engine at 90 deg. and use a different engine mount. I have a dubro mount, drilledfor a Saito 1.00 that Iwill use. I will need to re-drill it but since it's a long4 stroke mount I can use two of the holes and drill two more. I will also have to grind alittle of the muffler brace to clear the mount.

I also put the decals on the rudder.

I got back to work today doing the fuel tank installation. I replaced the230cc (7.77oz)tank with a 380cc(12.84oz). That required modefying the structure to accept the larger tank. I would have liked to move the tank back a little closer to the CG but due to the location of the forwardwing bolts that was not possible. I suppose Icould have used a header tank setup.

I then moved on to installing the servos. All of the cutouts had to be enlarged to fit the Futaba servos and the servo tray was 1/8" too low.

awesome...Keep us posted!

There is so little info on this!

Thanks Kostas1, I will do my best. You are right, there is not allot of info on this plane. Last night we had a club meeting so I didn't get to work very long. I did get the stabilizers mounted, it's begining to look like an airplane now. Everything went together well. Both stabilizers were square and levelto the fuselage without any adjustment needed. The more I work on this plane the more I'm impressed with it. Thats not to say it has no flaws, I have found a few minor ones. The servo tray was too low, the right elevator half is 1/8" longer than the left and the T-nuts on the firewall had so much paint in them they were un-useable.

I will get more time today to work and I'll post more photos tonight.

And here is the manual in .pdf format for anyone interested in seeing it...

Today I spent a good bit of time working on the Extra. I put the factory landing gear on just to see what it looked like and I couldn't get them off fast enough, they look terrible. The dubro landing gear will work but I had to put a 1/4" spacer under it to get it mounted. It will work for awhile but I will replace it with a carbon fibre gear when I can find the right size. The gear from the great planes extra 300 kit wouldfitvery well but they are aluminium. The size needed would have a mounting plate 1.25" X 4", be 14" wide at the axles and be 5.5" tall. I used epoxy appliance paint to paint the dubro gear, turned out pretty nice. I didn't get any pictures yet because they need to cure before I handle them. The picture is of the factory gear and the other is the area at the bottom rear of the engine.

This plane would be super easy to convert to electric.

I also got the radio gear installed and hooked up. I've never had a planewith ailevators on it so I'm looking forward to seehow fast it will roll.I did a preliminary balance to see where it was going to balance and it was very nose heavy. I decided to put the battery as far back as I could so I made a mounting plate and tied the battery to it. This was a very tedious job and I learned several new words to describe my feelings about it but I won't repeat them here, there may be children reading the posts.

It's really begining to look like an airplane

More photos.

The wing is truly symetrical and it will fit upside down. I would imangine you could fly it this way. But I won't.

I decided to use the factory control horns but I may change they to robart horns later if they won't stay tight.

I thought I would throw in some pictures of my friends 43lb all electric helicopter.

I've been unable to post to RCU for a couple of days now due to a problem with my AVG 2012 program. Had to turn it off to make posts. In that time I've finished the assembly of the Extra 300.

Laying out the cutouts and doing the cutouts on the cowl were straight forward and came out looking good. The cowl has a slight upward tilt because I didn't want to add another hole to the top to clear the carb.

It came out looking pretty good I think. The AUW was 7 lb 10oz and it balanced perfectly at 4" back from the leading edge right beside the fuselage with 3oz lead on the tail.

I took it to the field today for the maiden flight. I had a nice breeze right down the runway. After I got the engine tweeked, I taxied out to the centerline and pointed it into the wind. I advanced the throttle very smoothly and it tracked pretty straight with just a touch of left rudder. Lifted off in about 60' and flew straight with a gentle climb. A couple of passes to check the trim, it took two clicks of up trim on the elevator and she was flying straight and level. I was impressed.

I made several passes and did a couple of rolls to get comfortable with the handling. I then went up high to check the stall. It dropped the left wing and rolled on the stall. I added a little power and she was flying again. I was then ready for my first landing approach. The first attempt was too high and too fast and I had to go around. The second attempt was perfect. I came in with 1/4 throttle, it has a very predictable sink rate and the landing was very smooth on short cutgrass.

I am very happy with this plane. My first flight was with a Pro Zinger 12 X 6 prop and was not very strong. I changed to a Pro Zinger 13 X 6 and it was much better. I believe when this engine is fully broken in it will be a powerhouse.

Hi KAP2011,

did you made any changes on the elevator servo's? fi by replacing it with 1 servo and a closed loop?
I recently bought the same airplane and I found it pretty strange to use 2 servo's for elevator, they could have opted for 1 servo in the middle with fi a long control horn.
Oh yes I did the same, I replaced the tiny fueltank (felt like a 150 ml tank..) with a Dubro 12Oz/350 ml tank, that should be enough for 8/10 mins flying. Used the dremel indeed to largen the 2 frames which holds the fueltank
I was able to purchase a OS Max fs115a for a very good (dutch) price, so that will be my powerhouse. might be very overkill, we'll see...

Hi marcelvdwart

No, I stayed with the twin elevator setup because I was curious how it would work out. I agree, it could be done with just one servo. I've got mine setup as ailevators tied to the ailerons thru the transmitter. They work great but take some getting used to. The OS FS 115a is a bit of overkill but it should fly like crazy. Some people complained that the control surface throws were too small but I have found them to be right on.
Don't forget the dreaded high speed stall the Extra is famous for. Too much elevator throw is the culprit for that. The sugested throw in the manual is perfect.

Good luck
Keith

The Extra is dead, long live the Extra.

Cause of crash was determined to be an elevator half that pulled out at the hinge during a hard and fast split S. I really liked this plane so a new one will be on order soon. This time I'll use robart hinge points.

I had already pulled the cowl and engine out of the ground before I took the pictures but before it was buried about 10" deep. It was a spectacular crash, one of my best.

Upss I feel sorry for that!

Will you repair it?

No, the damage was too extensive. I've already got a new one ordered. I figured out that the elevator hinges were not glued properly. The hinge material will not wick the ca very well, maybe 4 mm of the hinge had glue on it. I'm surprized it lasted as long as it did. I'll use Great Planes CA hinges or Robart hinge points this time with epoxy.
All is well though, it gives me a chance to avoid any mistakes I made on the first one. The engine and all radio gear survived without any damage. The ground where it impacted was very soft, maybe a foot or two from the edge of a pond.

If I remember correctly somewhere in the past threads of my assemblies I've made a big demonstration
on how to properly glue the CA+ hinges!

"Search me" out

LOL, are you implying that I didn't properly glue the hinges?[:-]

no not at all.
It was a friendly suggestion, not only for you, but for everyone who wants to see my way!

Robart also makes 1/8" hinge points if the 1/4" are too big. You should also give Gorilla glue a true. It is a great time saver over the epoxy, plus it expands as it dries. I little practice and you can glue e both ends of the hinge point in at one time. It's suprising how little of the GG it takes.


david