Republic RC-3 Seabee

[whulsey]

Gil, great point about derelict and salvaged aircraft or cars in my case. Always get people asking why I'm taking photos of junked or under restoration cars; or sticking the camera under the car and squeezing off a shot. And it's just for that reason: how does that structure get from point A to B and what's supporting it.

[Gil]

Originally Posted by Ron0909

When you design, do you create with unfolding in mind right from the beginning? or is it something that comes into play after an initial shape has been determined?

Hi Ron,

Interesting question.

I always strive to design an accurate surface representation of the subject. The tools that I use, in this case Rhino, are best used to describe exactly that, surfaces.

When combined, surfaces describe the subjects volume envelope. The volume envelope when sectioned form ribs, formers and longerons of the model. A pair of lines formed by sectioning [e.g. transverse fuselage cuts] provide the input for developing unrollable surfaces.

The trick in all this is to select the correct section points to minimize angular discontinuities known as the "jaggies". That's where I've tripped off into negative mold land in an effort to move paper modeling into the more perfect world of surface tangent continuity - a noble purpose, ¿que no?...,

+Gil

[Gil]

Originally Posted by whulsey

Gil, great point about derelict and salvaged aircraft or cars in my case. Always get people asking why I'm taking photos of junked or under restoration cars; or sticking the camera under the car and squeezing off a shot. And it's just for that reason: how does that structure get from point A to B and what's supporting it.

Hi Hulsey,

Funny how that works. Modelers would know instantaneously what you're doing - shooting a walk-around...,

Finally made sense of a discontinuity in the Paul Matt side view drawing.

Working with side view photographs it finally dawned on me that the honorable Mr. Matt had made an error in the drawing [yeah, I know, the shame of it all]. This burned up an embarrassing amount of time before the rendered image matched the photograph.

I leave it to the readers to discover what that "error" is...,

+Gil

[Leif Ohlsson]

Something with the top rear fuselage not going all the way up to the TE of the wing. But then there must have been some fillet piece, mustn't there? - L.

[Gil]

Originally Posted by Leif Ohlsson

Something with the top rear fuselage not going all the way up to the TE of the wing. But then there must have been some fillet piece, mustn't there? - L.

First, a photograph showing the wing-fuselage intersection. Highlighted is the fuselage cut-line in red and where the wing rib would be highlighed in yellow. The Matt drawings do not go as far to show internal detail but accurately show a filet between the top of the wing and and the engine cowl.

A hint - it has to do with the side view outline. Look closely around the thread, it's in plain sight...,

+Gil

[Leif Ohlsson]

Wing incidence? (I don't count minor discrepancies in the sideline which could be due to perspective; but the wing incidence really seems to be off, right?).

[Ron0909]

The airfoil shape is off? I'm getting older and my eyesight is failing but it seems that the wing sits lower on the actual aircraft? Hows that for answering a question with questions

Ron

[Don Boose]

I will throw in my guess based on Gil's graphic, which seems to show pretty clearly that on the actual aircraft, the wing trailing edge coincides with the point at which the rear of the engine nacelle meets the rear of the fuselage. In the Russ drawing, the bottom edge of the nacelle meets the fuiselage a noticeable distance below the wing TE. I'm not sure if this is because the wing incidence is incorrect, as leif suggests, and which does seem to be true, or if the thrust angle or shape of the nacelle is/are in error.

In any event, this is the kind of thread that always fascinates me.

Don

[Gil]

Originally Posted by Leif Ohlsson

Wing incidence? (I don't count minor discrepancies in the sideline which could be due to perspective; but the wing incidence really seems to be off, right?).

No, wing incidence is correct in Paul Matt's drawings...,

Originally Posted by Ron0909

The airfoil shape is off? I'm getting older and my eyesight is failing but it seems that the wing sits lower on the actual aircraft? Hows that for answering a question with questions

Ron

No, the problem is not with the airfoil nor its position...,

Originally Posted by Don Boose

I will throw in my guess based on Gil's graphic, which seems to show pretty clearly that on the actual aircraft, the wing trailing edge coincides with the point at which the rear of the engine nacelle meets the rear of the fuselage. In the Russ drawing, the bottom edge of the nacelle meets the fuselage a noticeable distance below the wing TE. I'm not sure if this is because the wing incidence is incorrect, as leif suggests, and which does seem to be true, or if the thrust angle or shape of the nacelle is/are in error.

In any event, this is the kind of thread that always fascinates me.

Don

No, all that is in order. Care must be taken on the engine nacelles - replacement engines are the norm requiring cowl modifications...,

A hint - it has to do with the side view outline. Look closely around the thread, it's in plain sight...,

A visual cue might be in order - click on the top of the photo for a larger frame size and examine closely...,

+Gil

[Don Boose]

I am clearly out of my league here. The only other deviation that I can see -- and it is very slight -- is that the tail boom on the Matt drawing is a bit thicker than it is in your rendering.

I will await the revelation of the actual answer.

Don