Hello from Melbourne, Australia

[RolandD6]

Hi Folks

This is my obligatory first post on Polyloop but I do appear elsewhere from time to time.

My primary interest is modeling airplanes, both flying and as 3D artwork. I have built a few of the former but have yet to create a bit of 3d art.

My primary 3D tool is TurboCad Pro 14 but I also have Carrara 6 Pro, Amapi Pro 7.52, Poser 7 and Shade 8. All of the latter are new to me but I becoming more familiar with Amapi because if has a direct link with TC in my current project, a 3d model of the Pfalz D.IIIa, a WW1 airplane.

I expect Amapi to help me solve the problem of modeling the junction between the lower wing (it is a biplane) and the fuselage. The fuselage of late war Pfalz airplanes featured a compound curve molded wooden shell (like some canoes and surf lifesaver boats). There where few hard lines to see in photographs and there is little dimensional information available for the Pfalz D.III. There are four examples of the later Pfalz D.XII still in existence but that airplane is smaller and different to the earlier D.III although it does provide some clues to the likely surface structure of the D.III.

I have posted all of my personal research work on the Pfalz D.XII on this site:

http://www.wwi-models.org/Photos/Ger...XII/index.html

and a little bit of my 3D efforts on the Pfalz D.III on this site:

http://www.smallflyingarts.com/cgi-b...82082633/60#60

More later if this subject this of interest.

Paul

[mayito7777]

Welcome aboard, grab a chair and have fun.

[RolandD6]

Thank you mayito777

[Pete Exxtreme]

Hello,
You should maybe explain what your junction problem is Usually it's not the tool which is guilty when you can't model something but the way you want to model it.
Some screenshots will help to understand the concern

[RolandD6]

Originally Posted by Pete Exxtreme

Hello,
You should maybe explain what your junction problem is Usually it's not the tool which is guilty when you can't model something but the way you want to model it.
Some screenshots will help to understand the concern

Hi Pete

The wing/fuselage joint on the Pfalz aircraft is a sweeping continuous 'S' curve. The basic shape of the lower fuselage is based upon elliptical cross-sections (more-or-less). The curve of the wing root is tangential to the fuselage contour and meets the root rib at an angle that I have determined to be about 24-28° (it varies along the rib). See my photos (Contour@Wing Leading Edge.jpg, and Contour@Wing Trailing Edge.jpg) of a very similar aircraft (Pfalz D.XII) that came after the Pfalz D.III. Unfortunately there are no D.IIIs left for anybody to measure. There are a few full size 'replicas' but I treat them as suspect until proven otherwise.

Photos Pfal-D3.jpg and Pfalz_DIIIa_2.jpg were taken during WW1 and they illustrate the shape of the airplane around the fuselage-wing root junction. I have managed to establish the likely junction of the 'fillet' and the surface of the fuselage. This is illustrated by the cut-out shown by LowerFus-WingRoot.jpg which I generated in TurboCad. By trial and error I have establised the likely profiles of the area directly above the middle portion of wing root profile and the bit that fairs the trailing edge into the fuselage. I have not yet rendered a surface over them and in TurboCad I may have to resort to defining x,y,z coordinates for points on the surface. The work I have done so far will provide that information if I have to go that way.

Sections.jpg shows some typical sections. The area around the leading edge of the rib profile is a much more difficult task (see Pfalz_DIIIa_2.jpg). Trial and error with x,y,z coordinates may achieve a suitable result (eventually) but that is a very hard way to go. I had been hoping to get a good approximation by using one or more of the surface tools in Amapi.

I believe Amapi wil generate a surface between 3D contours (ie. non-planar) whereas TurboCad's surfacing tools use 2D profiles (eg. the lofted surface in LowerFus-WingRoot.jpg. The profiles do not have to be parallel to each other but they must be planar.

I would be very happy if somebody can show me how to achieve the desired result in Turbocad.

This is more of an engineering project than an 'art' project. it is important to me that my drawing is a good fit to the available information that has survived from 1917. There are a few dimensions and some sketches and drawing that were done during WW1 but none of them are much help with this problem.

I hope I have explained to problem sufficiently.

Paul

[RolandD6]

Missing image of typical fuselage cross-sections

[Pete Exxtreme]

OK i've lurk at your website and effectly seen that you're talking about engineering of the plane..
Maybe that one of our nurbs gurus (Piem, Hugo ?) will have an idea about that ? Usually we have a more a polygonal approach here which is not relevant for engineering

[bwtr]

Welcome from Adelaide, South Australia.
Brian Rohde

[-ash-]

Hi Paul, welcome.

[RolandD6]

Thanks Brian

Thanks Tony

Paul

[3webjam]

Hi Paul, welcome here on this forum - it is a great bunch of people here.

Have fun!
Jacqueline

[RolandD6]

Thank you Jacqueline; I hope to.

Paul