ValuePlanes Seagull

Started by Michael, February 19, 2021, 08:50:59 AM

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Michael

#15
The wings were also able to be mostly assembled before gluing. These are not pinned down, nor built over plans. Construction is basically tabs and notches, and the parts fit is snug. I keep referring to the drawings, but it's no substitute for plans or instructions. The only problem is that some parts (spars, etc.) were perhaps only a millimeter longer or shorter at some ends, and this was very hard to observe until things were glued. The lack of instructions remains a serious challenge. Anyway, a little bit of sanding, repositioning and creative gluing solved any obstacles I faced.

Michael

Michael

Back to the fuselage.

Without instructions or an order to the construction, I assembled the side sheeting before gluing it to the fuselage, to measure whether the sides overlap the top and bottom, or the other way around. Once I confirmed that the tops overlap the side sheeting, I glued on the side sheeting.

Next, I will bevel the bottom of the structure and the bottom sheeting, and glue it to the frame. I'll leave the top open for now, to facilitate the radio and linkages installation.

Michael

Michael

Adding balsa surfaces to the fuselage and wings.

As much as I enjoy building this kit, I've come to the conclusion that it is definitely not for a beginner, especially because it lacks any kind of instructions. I find I'm using techniques from over 40 years of model building experiences.

I'm using green masking tape and heavy batteries to hold things down as they dry.

Michael

Michael

Wing sheeting added.

Wings sanded and sheeting trimmed.

Ailerons marked between 2 rear spars, cut out and sanded. A front edge will be glued onto the ailerons, and sanded to a bevel, and then hinged.

Michael

Michael

Ailerons trimmed and sanded to shape, and end-ribs cut from scrap and glued in.

Leading edge of ailerons glued on, and center-hinge line marked.

Leading edge of ailerons shaped and sanded to a bevel.

Wing tips glued on and shaped/sanded.

Despite no instructions nor plans, the progress is logical and based on decades of past experience.

Michael

Michael

Fuselage nose carved and sanded to shape.

Tail feathers sanded, leading moving surfaces beveled, and elevators joined with a wire.

I'll start the radio/linkages/power-system/installation next (tomorrow morning), before sheeting the fuselage top and before covering covering.

Michael

Michael

I've complained about the problems with this kit, but I realize I have enjoyed working on it so far. The included hardware package is more comprehensive than I thought, and the laser cutting is close to exceptional.

The plywood parts for the aileron servo holder/hatch are a tight fit. Nice!

Magnets (included) for the snug-fitting battery hatch fit tightly and securely in the laser holes. Just a drop of CA glue locks them in place.

I decided to replace the plywood windshield with my own removable balsa version (better fit), so I can have better access to the inside of the fuselage if I need.

Wire cables and sleaves are provided for the tail controls, and they fit nice and snug within the laser cut holes in the formers, but I will not be using these. The wires would come out of the fuselage under the stabilizer, and I prefer they exit above the stabilizer, for added protection from water when float-flying.

Michael

Michael

Elevator, rudder and ailerons hinged (but not glued). Tail temporarily in place. Servos installed.

The tail is not straight with the wings. I'll have to shim the fin and stabilizer.

Once the radio and linkages are fully installed, I'll install the power system.

Michael

Michael

Control horns and pushrods for the tail are temporarily installed. Everything will be taken off when the model will be covered.

The kit comes with good quality screws and EZ-connector type hardware, but I chose to use other brand units.
I also made Z-bends in the wire for simplicity. KISS!

The pushrods and control horns also came with the kit.

Michael

Michael

Pushrods set up on a straight path to the tail control horns. Plastic sleeves glued at various locations.

Fuselage top glued on; the rear portion with grooved slots/holes for the pushrods.

The screws on the elevator are temporary.

Michael

Michael

Aileron linkages done (of course, hinges are not glued yet).
I use a Z-bending pliers. It makes work much easier.

I still have to mount, or figure out how to mount, the tip floats.
The drawings do not indicate how to secure them to the wings (other than through a slot), nor how far down they should be.

I'll work on the power system first. The kit box, website and drawings suggest a 3S system. Considering the size and weight of this plane, I'll be using a 4S system (E-Flite 25 870 KV motor, 60 amp ESC, and an 11/8 prop, or a similar 3-blade if the 11 is too big).

Michael

Michael

Wiring is all done.

Next: more sanding (and maybe some fiberglassing/painting), covering, power pod installation, and tip-floats installation.

Michael

pmackenzie

Moving right along Michael!

I posted earlier that I had ordered one of the Value Hobby kits from Great Hobbies, the Skywalker 65.
It arrived late last week, and I dove right in for a change :)

Here is where I am right now, all framed up. 20 ounces as it sits, no electronics in it yet. It is bigger than the picture makes it look, too big to fit in my shop in one piece!

Unlike Michael, I did get "instructions". But they are pretty terse, and gloss over all the tricky parts.
Quality was good overall, but I did swap out the wing sheeting because what was provided was just too heavy.
So I would rate it as good value, but a "builders" kit that will require some experience to build.

I made a few minor changes:
-Main visual one was to add cap strips to the ribs. Just looks a lot nicer to me with them :)
-I  added a few extra "sticks" in the fuselage that added a ton of stiffness to the structure. They really should have been part of the original design. (See next post for details)
- Thrust line is shown as zero-zero. I modified the fuselage parts to give it 2 degrees down and right
-I built in some washout in both tips, about 1/8"
- I will probably add a "dummy" engine cylinder, perhaps some sort of sparker. Should be fun to make :)


Left to do before covering: I want to figure out how to make the stab and rudder bolt on to make it easier to transport and store. Perhaps the landing gear as well for the same reason. Trying to decide if I will change the wing to bolt on, rather than rubber bands.

Nothing about CG on the plans. They suggest a 4S setup, but to me I think a 3S set up will be plenty. But the nose is short, so it might need the weight of the 4S?

Pat MacKenzie


pmackenzie

#28
Details on the added structure.
At each position where the top and bottom formers were located I added the vertical pieces shown in red, and the diagonal stiffener shown in blue.
All are 3mm x 6mm balsa, using scrap from the kit. I think the added weight for all was less than 3 grams.

The yellow arrows show what happens when the covering is shrunk, the top and bottom want to push together.
The original design did not have the vertical parts show in red, so there was nothing but the bending moment of the longerons to absorb this stress.
They are basically free to bend as the yellow arc shows. The structure felt very "springy" to me. Adding the red parts made it feel stiff.

But it was still pretty soft in torsional strength. The structure was relying on the small area of the glue joints at each station to absorb all the torsion.
This sort of structure should really be considered as being free to pivot at the joints, so adding a diagonal as shown absorbs all the torsional loads.

To see this, glue up a 3" square from 1/4" sticks. Push in on opposite corners and note the stiffness.
Now add a diagonal and repeat the stiffness test. It will basically not deflect at all.

Michael

Wow, you built quickly! It looks big!

Your 'customized' steps all make sense. I'd agree with you that these kits are a good value, but definitely for someone with a fair amount of building experience.

I hope to your plane fly this season.
Michael