Scratch Built Grumman Goose G-21A

[scon10]

I like the engineering on the movements of ailerons and flaps. Clever!

[MacSongLi]

That is a heck of a lot of very nice work in the internal workings. Well done.

Gary

[T haf]

Here I've got the electronics for ya.

3 AAA batteries powered in series to a switch. From the switch is splits in parallel 3 different lines. The first one to the light board, and the second two to the motors that will go to the radial engine. I'm super happy with it. It worked the first time, no shorts or open circuits. Now I can work on finishing the skin for the wing. After that, I'll start on the engines.

The lights are wired to replicate landing lights, red and green navigation lights, and strobe lights.

[Siwi]

Factoring in the placement (and replacement) of batteries and wiring into a model design can be interesting. Do you plan to have a removable panel on the top of the wing in order to change them?


I like the design of the aileron mechanism (and all realistic moving parts in models) - might experiment with something similar to make sliding doors on trains. May I ask what tool you used to create the holes, and whether you strengthened the moving card parts in any way?

[T haf]

Siwi, I'll start this one out by answering some of your questions.
Yes! there is a removable panel on the top of the wing. My wife was the one who came up with the latching mechanism too. She's pretty and smart!

The paper thicknesses.
I will typically use .5mm card double laminated to 1mm for the majority of my former and functioning parts. For example, inside the aileron is a 1/8" dowel running the length of it. Using my double laminated card I cut 4 strips to the correct size and glued all four 90 degrees off one another giving me the structure that would be needed to then wrap it all with a thinner standard card thus creating the complex aileron shape.
The tool I use for the holes is the newest addition to my tool collection. It's called a Japanese Press Drill or something like that. It comes with 9 tips of varying sizes spanning from 1mm-5mm in .5 increments. I got it off amazon for 70$. I can confidently say that it is the most impactful, valuable, and beneficial tool I own other than my x-acto knife. It offers me both holes for designs, aesthetics, and accurate small details as well as punched paper for bolts and other disk parts. I completely and whole heartedly recommend this tool.


Moving on with the build...

Here I've got for the what will be the second to last update about the wing. The wing is completely wrapped, there are no more formers showing. I've started on the engine nacelles, engines, and finished the electronics.

The wing may be the single best thing I've ever built out of paper. The joints are pretty tight in tricky areas. The functioning parts move with very little friction. The shape stayed true to my design. The engines look fantastic in my opinion; compared to my test engine I built earlier in this thread, they were exceptionally smaller and simpler. The hardes part in this update to build would have to be the wing nacelles that span back over the top of the wing. They were a challenge to get right.

Up next on the build is the engine cowling, which I've started. Then after that I need to build a latching system to attach and detach from the fuselage. Once those are complete I'll be able to paint it.

I'm not too sure on the paint scheme yet, but I'm leaning towards maroon and cream white.

[Isaac]

Impressive work that will bring motion and pazaz to your model.


Great ideas.



Isaac

[T haf]

I've finished the engine nacelles. The wings are nearly done. All I have left to do is put the exhaust system on. Before I do that, I need to paint underneath the mufflers.

For the landing gear, they were fun to build. For these, pictures tell a better story. I got the tail gear too. The front gear moves manually and the tail gear moves off a mechanical lever.

As for the rudder, I finished building the framework, It still needs some work. I cant finish building it yet. I've gotta get the elevator finished first. The controls came out pretty good for both the rudder and elevator. As a bonus I added something I've never tried before. I built a functioning trim tab. when the rudder pushes one way the trim tab pushes the opposite. It doesn't work super well, but it does. Small detail that adds to the build.

Lots of moving parts on this update. I'd love to answer any questions about them.

[Siwi]

Moving parts are a wonder to behold. Aside from the trim tab I can see how they all work but I have questions:


- Did you copy the design of the moving parts from prototype blueprints, or are they adapted to fit the practicalities of the model scale?


- Will you add gear bay doors to the rear wheel and make them open/close as part of the same mechanism?



- How do you make the parts loose enough to move freely but stay in place when desired? (specifically the main landing gear) Is there some kind of latching mechanism?



- Could you help me design a sliding plug door for a train...?

[rifleman]

t haf thats some great modeling going on big well done to you looking awesome

[Mike1158]

A great airframe, nicely done.