Dancing Wings Tiger Moth 980 cm wingspan

[Michael]

Even though I plan to fly all winter long, there are some days when the weather is just not right. For those days, building a new model is in order!

My newest project is a laser cut balsa and ply kit of a Tiger Moth. It has a 980cm wingspan, so it should fit in most cars fully assembled. The version I bought was under $300, but that also included a brushless motor, speed control, servos and a propeller.

It looks like a great quality kit, but I started having some reservations once I got started.

[Michael]

The fuselage sides are made of balsa, with plywood and balsa parts added for strength where needed, however, the rest of the basic fuselage construction is all in plywood. The parts fit is fair (not very good), and the gluing was not what I anticipated. While balsa glues to balsa with CA very quickly, plywood to plywood joints require more (medium consistency) CA, and more time to dry. Also, minor cutting and sanding of parts, to help fit, is also not as easy as with balsa.

The fuselage is not built over plans; it is basically assembled and glued together in your hands or on your workbench. In fact, there are no plans, and no 3-view drawings for reference.

Anyway, complaints aside, it took me a couple days to assemble the fuselage, and now I am beginning to sheet (balsa) the upper fuselage.

I would suggest to anyone, to trial-fit and assemble parts, even a few steps ahead, to make sure parts fit, before committing to glue.

[Michael]

I use an old technique to help in sheeting curved sections with balsa.

Before actually gluing, I soak the pieces that will be curved with Windex (plain water will do almost as well). I let it soak in for a few minutes, and it helps the wood to bend without cracking. I then secure the parts (wood grain perpendicular to the bend) with elastics to a curved shape close to the size of what's needed. This dries quickly, and the balsa retains most of the curve.

With the curve in the balsa, it is easier to apply and glue, and less likely to crack or break.

[Frank v B]

Balsa dust!  Love it.

The first day of spring is when Michael has finished his 4th project.
This is project #1.  Please keep building to help speed up spring!

Frank

[Michael]

Fuselage sheeting is almost complete. The rear sections weren't wide enough, so I had to add a strip of balsa. I built the fuselage almost perfectly, but some parts just don't fit right.

The building process is slower than usual, because plywood glue joints take longer to set than balsa glue joints.

I would have to recommend this kit only to experienced builders. Anyway, I'm still enjoying building it, and assuming it flies well, the extra time and work will be worth it.

[Michael]

Basic fuselage construction done. Not yet sanded.

[Michael]

The tail is constructed entirely of laser cut balsa. There are no plans, but the parts fit here was essentially perfect. I initially glued the pieces together with white glue over wax paper`. CA glue would have stuck to the wax paper too much, however, I soaked a little CA into each joint once the structures were removed from the table/board. Sanding will be done later.

The pieces are assembled onto the fuselage, but not yet glued. tapered and curved sections are carved and sanded to shape.

[Michael]

The center section of the upper wing, is of plywood and carbon fiber tube construction with balsa sheeting.

The instructions were not very clear as to which plywood pieces went where, but a little common sense (regarding how the struts would be secured) went a long way. I always suggest reading a few steps ahead of what one is working on, so you will have a better idea of what's needed as you build.

The instruction sheet suggests wetting the balsa to bend it over the curve of the front ribs. In my opinion, that would be very difficult to do without breaking the balsa, so I came up with another idea.

I made a series of cuts, half-way through the wood, so the wood would bend while dry, and using masking tape on the inside to make sure it wouldn't come apart, in case the wood split along one of the cuts. The technique worked perfectly.

The kit includes formed carbon fiber struts. They didn't fit easily into the center wing section nor the fuselage, but a little cutting and sanding silver this.

[Michael]

The upper wing is built over provided plans, but without instructions. There are 2 drawings on the 'instruction' sheet, but I would still recommend fitting all parts together before committing to glue. It took an hour, maybe more, to cut the pieces (plywood and balsa) from the sheets, and to sand off the little tabs that held the laser cut parts to the sheets of wood.

It's a very light structure, fitting onto the center section on carbon fiber tubes. Each individual wing has been glued together, but the assembly (wings, center section, struts) have not yet been glued. I put them together to make sure everything fits.

The lower wing (I'll start in a few days) is more complicated as it has servo bays and ailerons.

[msatin]

Excellent progress Michael.
I really liked the technique of making "half way" cuts to bend the balsa over the front curve of the ribs.
The resulting gaps are so small that I don't think you'll need to fill them in prior to covering
Very Nice!

[Michael]

Thanks, Mark. I'll sand them, but not fill them.

[Michael]

Lower wing construction.

Warnings:

1. If you want to build this kit, be aware that the lower wing should almost be put together, before committing to glue. If the ribs are glued onto the spars first, then some parts won't fit.

2. There is a 3-piece plywood rib made up of parts D8-1, D7 and D8. These are not shown properly on the plans. The D8-1 should be facing outboard, and D8 inward. Otherwise, other parts won't fit.

3. Curved parts on the wing tip are too tall. They're easily sanded to shape, but it's easier done before gluing them on. As with the rest of the wing, the entire wingtip should be assembled completely, and then glued.

Anyway, it was still fun, and the lower wing construction is done. Ailerons are next.

Another warning: The illustrations intended as instructions, do not show servo installations. I'll figure it out later.

[octagon]

Looks great. Obviously not a beginners kit so good of you to point out what needs paying attention to.

[Michael]

The ailerons are shown on the plans, and slightly on the instruction-drawing, but with no specific instructions about how to build them. The construction is mostly of plywood, hardwood, and only one piece of balsa. I needed thin CA, medium CA and CA accelerator to put this together.

There are two errors on the plan. After carefully fitting parts together without glue, I found that:

- The plans infer that part D29-1 fits behind part D29. That is wrong; D29-1 is in the front; on the front face of the aileron facing the rear wing.

- D25 is shown flipped 180 degrees left/right, and forward/backwards. The side tab on D25 must face towards the wingtip, so the small tab fits on the bottom of rib D23.

I assembled the ailerons as follows: first, the 2 leading edge pieces were glued together, then the small ribs and D25 are glued on, the the trailing edge is glued, and lastly, the wingtip parts are glued on.

I used some of the supplied balsa strip-wood to fill in the edges of the aileron leading edge, so I could later sand them to a double-edge bevel, which will be slotted for hinges. This was obviously needed, but was not indicated on the plans nor instruction-drawing.

[Michael]

Basic construction is done. The instruction-drawing shows some assembly and rigging images, but first I'll sand everything, install (but not yet glue) hinges, install landing gear, install radio/servos, all assorted horns and struts (but not yet glue), motor system with ESC, finish battery placement/tray, and cut/fit the cowl.

Then covering, assembly (with glue) and rigging.

Instructions are minimal. For example, the instruction page simply says: "Connect the aileron wing with paper hinges .... Of course, that's not what I'll do. CA hinges are included with the kit.