recent change:2017-02-12

What is glattCAD Flugmodelle?

 

glattCAD Flugmodelle came up in 2005 as an idea to escape the boredom of the daily train run to and from work. Just for fun, with the notebook on the lap, in some thousand hours in the cramped regional express a series of high-quality 3D CAD drafts evolved for rc model aircraft and components. And development, improvement, testing and retrofit is heading for series production readiness.

 

DH-88 'Comet' and Messerschmitt Me-209 are available in the online store at fair prices!
Laird Turner LTR-14 and Heinkel He 162  are actually built up in several testversions. They are intended to be ready for sale in 2017.

 

Concept

 

Modellers interested in semiscale and scale replicas of historical aircraft are primarily addressed. The main focus in the selection of models is on those being rare in the shops and on the flying fields.
The models have lenghts or spans from 80" to 120", therefore they can still be called "transport-friendly". With regard to production considerations such dimensions can be handled with reasonable effort. Equipped with eight to fourteen serial lithium-polymer cells they will particularly be predestined for modern electrical drives.

The aesthetic quality of the wooden construction is exceptional. It will probably be found nowhere else thus exclusively distinguishing glattCAD Flugmodelle: The combination of thoroughgoing funcionality with the grace of playful detail solutions. RC modelflight is fun - that goes without saying. The union of flying and building in this amazingly different type of form almost results in a new variation of our passion.

 

"You actually should sheet glattCAD Flugmodelle with transparent film only!"

 

The designs meet the requirements of a simple assembly. However some experience in kit building and routine in flying bigger rc models should be demanded. Despite the high number of components the mounting is remarkably easy.  The assembly of a glattCAD Flugmodelle kit looks more like a puzzle where each part interlocks with its adjacent part than the building of a classical rc kit. Over- and undersize of all slot and tongue constructions reduces the need for additional filing work. Theoretically a fuselage or a wing could be nearly completed on its assembly frame without having used a single drop of glue.

The search for reliable templates, historical plans and pictures at sufficient definition is rather exhausting. Generally at least two different sources of (hopefully) different authors are taken for verification purposes.

Good flight and scale quality are written far on top in the requirements specification.
To a certain extent aerodynamic weaknesses of the historical aircraft pattern, typical original vs. model scale problems or certain fluid dynamical constraints of the original can be compensated by the smart design of the profile distribution and the suitable choice of stability parameters. On the other hand it is a taboo to deviate from the aircraft´s outline! State-of-the-art software for polars determination and vortex lattice analysis to process the flight dynamics is used even before beginning the actual design task. All variables relevant for the intended behaviour of each flight phase need to be simulated und initialized.

It is equally important to reconcile mass, strength and stability as a central requirement.
During the CAD work the take off weight is consecutively extrapolated and monitored. Values for density are assigned to the CAD volume elements in order to avoid surprises. In case during the drafting it is realized that additional reinforcements need to be inserted or stronger frames are to be dimensioned aerodynamic parameters can be recalculated at an iterative step. As a consequence the design can be adapted. Thus a significant plus of glattCAD Flugmodelle reveals in der direct integration of fluid mechanics mathematics with the design draft:  Everything comes from a single source, production too, "Made in Germany" goes without saying.

 

Project Status

 

Currently two new models, Heinkel He 162 and LTR-14, are built up. The He-162 will be available in two short kit versions: EDF and jet driven. The findings from construction and flight testing done by experienced modellers and pilots are incorporated in a redesign phase and end in a richly illustrated and intuitively comprehendable manual.

TS-11 Iskra is at an advanced draft state. Two experienced modellers and jet pilots could be acquired for building two prototypes. The machine will measure 2,50m x 2,80m.

On 24th of June 2012 the DH-88 Comet successfully completed her maiden flight. No trim corrections were required, so her correct aerodynamic and structural design were confirmed. The Comet flyes "like on rails", very neutral, without any tendency to kern or changes in in-flight attitude. A fixed landing gear had been mounted temporarily. In spring 2013 the finish was completed and the retractable gear was tested made suitable for series production. The prototype shines in 2C-gloss, in the colours of the black and golden G-ACSP Black Magic. As expected before some requirements changes evolved from the findings of the assembly opening out into an extensive review of the 3D CAD design. The result ist very respectable! But please convince Yourself ...

Hall Springfield Bulldog and Me 262 short kits are available in the SHOP. They both span about 2 m. Both constructions base on VTH paper plans.

 

No CAD (Computer Aided Design) without CAM (Computer Aided Manufacturing)

 

Of course it is not about to create pattern sheets for fretwork or attractive screensavers. Modern 3D CAD software allows the design of complex free surface shapes, half-timber and even geodesic structures. Without a powerful and reliable CNC milling machine, however none of the computer airplanes would ever roll out on the runway for its first flight!

Before feeding the mill with the model data there is a lot to do:
In a first step a precise three-dimensional surface model is designed already taking into acccount the different sheeting thicknesses. These very homogeneous surface elements serve as virtual cutting tools for the development of all formers, ribs, spars and many other components. The processes following deal with porting all the CAD
elements on flat surfaces, representing the virtual counterpart of the plywood or balsa sheets well-known from the good old quick-build kits. Virtual 3D devices for positive master forms or negative laminating molds are compiled at this stage, too.  Finally cutting paths, speeds und milling strategies are developed and optimized for the machine.

Special thanks to Flo Bauereisen, supporting glattCAD Flugmodelle by his extensive knowledge in all questions of resin technology and mold building. Hans-Gerd Moelder prepares and tests a prototype for the turbine version of the Heinkel He-162 with great knowledge in modelling. Mario Buehler and Rob Schmid build, built and test their Me 209 prototypes.

 

Another powerful CNC milling machine from Sorotec was put into operation
- reserved for glattCAD Flugmodelle!

 

Outlook

 

After many years of experience with CAD and CAM, having incorporated the results from the prototypes´ assembly and testing, You - dear modellers - shall benefit from this idea. Haste makes waste! The  D.H. 88 Comet and Me-209 kits can be purchased in the online store. As a next step glattCAD Heinkel He 162 and LTR-14 will be launched and available in the SHOP in 2017. TS-11 is going to follow.
 

 

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