I Just finished up my Somthin Extra and I haven't even had it in the air yet and I already have the urge to build something else. I had a 4* kit in the closet so I decided to get going on it. I figured I'd post progress on here since this plane gets a lot of questions from beginners. I've built 2 4*'s in the past. The first plane crashed and taught me 2 valuable lessons: the first is to be careful when checking your CG and the second is to never fly in the fog, not even light fog. The second plane had a longer lifespan, I flew it for a few months and sold it. The 4* is a good airplane but there are a few things I don't like about it such as the ugly canopy, odd nose shape, flexible wing with no sheeting, etc. I decided to correct those things and others in this build.

I started with the wing. I know the stock 4* wing is light, easy to build and works well when built straight. I just don't like something so flexible that I can warp it just by shrinking the covering. For this latest 4*, I decided to scratch build a wing with a D-tube construction and cap strips. I started by using a W-1 rib as a template and making the spar slots deeper. I eliminated all of the small sub-spars. I then cut a set of new ribs from this template. Since I was clipping the wing and using sheeting, I figured I could space the ribs at 4" rather than the 3" shown on the plans. Once the shear webs, sheeting and cap strips were installed, the wing is straight and rigid while still being light. I also made mounts to put the aileron servos in the wing. Once the other half is done, I'll come up with some sort of wing-tip shape.

This is the most that I have ever altered a kit so I hope that I don't regret it. There's only one way to find out.

Have you fit the dihedral brase yet?? I just started a 4* 60 last week and I found that I put a bit to much presure on the top spar at the root and I ended up with an opening for the brase that was to small. I had to cut out the spar from the first two ribs. I'm going to make a pocket for the brase usning 1/8" balse with vertical grain.

Your D tube modification looks interesting. I wish I had done that also. To late now as I have one wing pannel finished and I'm not inclined to tear it apart for the mod. Maybe I'll just make some patterns like you didn for a replacement wing.

I'm going to reduce the dihedral angle by about 1/2 so I won't be using the stock ply wing joiner. I put shear webs on both sides of the spars between the first 2 ribs on the root end and cut an opening between the spars on the first rib. This creates a pocket for a wing joiner that is the full width of the spars. I'm not sure if I'm going to make the joiner from solid hardwood or laminate so light ply; we'll see.

I got home alittle early this afternoon so I finished the right wing. I built some wing tips and constructed the aileron from sticks. This aileron is 1/4" wider than stock, hopefully this will be an improvement rather than a problem.

Tonight I had a little bit of time to start on the left wing half. The first thing to do is cut out all 9 ribs from 3/32" stock using the stock W-1 as a template. Then I placed them on some scrap spar material, pinned them together along with 2 W-1 ribs and sanded them so that they all match. On 3 of them I used a forstner bit to drill holes for the servo lead tube. From there it's just a matter of laying out the modified rib placement on the plans and building up the wing. I've included a couple shots that show the shear webs glued directly on the back side of the spars, rather than in the center as shown on the plans. Another shot shows the 1/4" balsa doubler I added to each root rib. This should make drilling the dowel jole a lot easier.

Ok, the pictures should show up this time...

Here's the wing joiner that I was talking about. I'ts a lamination of plywood and balsa that comes out 3/8" in thickness and fits between the spars. I know the picture is blury but you should get the idea.

Here's the wing all finished except for bracing on the left wing tip and holes in the top sheeting for the servo leads. The only parts from the kit used in this wing were the basswood spars and the TE sheeting. The fuelage will be built more according to the plan, using the kit. The only deviation will be sheeting on the turtle deck and a cowl. Once I get to the horizontal and vertical stabilizers, I'll probably scratch build them too with a modified shape.

Always nice to see another build thread, and this looks good! Keep it coming Chuck!

I've started work on the fuselage now. It basically builds itself so there isn't alot to say about it. In the pictures you can see the modified turtle deck. Not only is it sheeted, it is angled different than stock, making F-6 taller and allowing the use of tail fairings. I should have taken more photos of these modifications but I got so caught up in things that I forgot. Basically, I started by making the headrest 1/16" smaller then cutting the tops off F-4, F-5 and F-6. I drew my new deck angle on the plans and determined the new height for the formers. I made the modifed former tops from scrap ply and glued them on. I only used a single 3/16x1/4 stringer down the top-center of the turtle deck. Then it was just a matter of wetting the 1/16 sheeting, cutting it to fit and glueing it down. You can also see that I'm starting on the horizontal stabilizer (not done yet). The solid balsa stab included with the kit didn't match up with the plans. I also tend to think that solid pieces can warp more easily than built-up pieces so I decided to just scratch build the stabs. I'll be adding some sort of curved tips to compliment the ones on the wings.

Chuck!! IT looks great! Keep going!

J

Tonight I got all of the tail section framed up. The horizontal stabilizer has a span 1.25" more than stock. The Elevator halves are 3/8" wider. The vertical stabilizer is 3/4" taller than stock. The rudder is 1/2" wider and the hinge line is angled back slightly. Hopefully these increases will make a great flying plane even better and won't make it too touchy. If it is, I guess I'll just have to reduce the throws and/or add a lot of exponential.

Here's a look at the tail section mocked up in place.

looking good. Glad to hear your SSE flew nicely. I debated between a 4* and an SSE but looks like your getting the best of both.

Between the SSE and the 4-star, I like the SSE better. It's easy to fly and very versatile. I had this 4-star kit just sitting though. I want to do some scratch building one of these days so I figured doing some scratch built stuff on this kit might be a good way to get comfortable with it. Plus, I'll hopefully have a fun plane to just fly around on Sundays.

I made alittle more progress tonight. I cut off the cheeks and got the engine mounted. I'm not too happy with the tank height with the engine sitting sideways. If I were to do this again, I'd probably lower the tank floor a little. Hopefully I won't have any serious fuel problems when inverted. I wanted to get going on the cowl tonight but I didn't have any foam for the tank and the hobby shop was closed before I realized it. This means I can't put the front deck sheeting on. I guess I could but I'd rather not try and stuff foam in from the back if I don't have to. Looks like I'll also be using a muffler extension in order to clear the bottom of the fuselage. I'm going to have to stop working on this for about a week due to a business trip. I'll resume when I get back.

Chuck,
I wouldnt recomend going for less dihedral in the wing. I did that with my second 4 star and I really didnt gain anything except adverse yaw , when you add left rudder the plane tilts right.

I've done some research on the subject and I've gotten mixed feedback. Some say it is no problem and they like the way it flys. Others, like yourself, didn't have good luck. I didn't build the wing flat because that made me a little too nervous; I just took out a little dihedral. If I think it ends up causing any problems, I can always build another wing.

Wow only ten days into it and you have all the major structure completed.
Very nice indeed [sm=thumbup.gif]

Well, I'm back home and got to work a little more on the 4-star. I decided to cut out the tank floor and lower it about 3/8" to get the fuel tank lined up better with the carburetor. Then I was able to sheet the front deck and build the balsa cowl. Here's a couple pictures of the roguh cowl. It still needs some shaping and sanding.

I got a little more done tonight. The pushrod tubes are in. The picture doesn't show them finished but they looked great after trimming and sanding. The elevator haves are joined, the rudder is hinged and the balsa for the tail fairings is glued in place. Tomorrow I'll get the elevator and ailerons hinged, shape the tail fairings and work on the servo mounting.

I managed to sneak a little time to hinge the elevator and roguh out the tail fairings. If all goes well I'll atart on the servo mounting and aileron hinging later tonight.

Here's the start of the servo mounting. I glued two strips of 1/4" square balsa down each fuselage side. 3/8x1/4 hardwood mounting rails sit on top of the balsa. I'm using the plastic tray that Futaba includes with thr radio sets. Once I get the CG set right, I'll glue the rails in place and add some balsa caps to lock them in place. The picture makes it look like my tray is a little crooked, maybe I'd better go back and measure again.

Looks good so far Chuck! What engine do you plan to use?

Looks great Chuck!!!
KEep it up!

Jeff

I'm going to use a Tower .46. I thought about something a little bigger but the .46 was just sitting around without home.