As an RC planes enthusiast, I already designed several planes using foam cutting technics.

To do this you will need a foam cutter machine and a "board" to pilot it. Regarding the board, I already published a cheap FluidNC 4 axis controller.

This controller has already proven to work very well. But it needs "software" to produce the Gcode and to control the board. This is exactly what this project is dealing with !

Although several solutions does already exist, none of them were (IMHO) simple and powerful enough for my needs... 

So I wrote two applications :

• WiHoWI (Wing hot Wire) devoted to design the Gcode file of the wings (or anything else !)
• hoWiGs (hot Wire Gcode Sender) devoted to drive the FluidNC controller

And the very first "full wing" cut with the tandem WiHoWi + hoWiGS

And no cheat it's hoWiGS which cuts this wing !

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WiHoWI : Wise CNC 4-Axis Hot Wire Cutter

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WiHoWI is a specialized CAD/CAM utility designed for 4-axis CNC foam cutting. At the beginning of this story, WiHoWI was "Wing Hot Wire" ... Now it is more "Wise Hot Wire" as it appeared to be generic enough to cut what you want to cut ... (almost) !

This software synchronizes two independant 2D profiles (Root and Tip) to generate precise G-Code for tapered wings, including complex internal cutouts and automatic stock material management.

Let's start by a quick introduction video showing the main features of the software

Key Features and usage

Dual Profile Synchronization:  Import Profiles: Use the `File > Open` menu to open existing projects (.whw) or use dedicated buttons to load .dat or DXF files for the Root and Tip. You can also import a .stl file containing the whole wing "at once".

You can use any CAD software able to produce "polylines" dxf. Currently tested with

• Lightburn (commercial product) (support layers)
• LibreCAD (free and Open Source) (support layers)
• QCAD (free and Open Source) (support layers)
• Solidworks (commercial / free licence for makers). Does not support layers natively during export but can save .dxf of a face (profile and cutouts in the layer 0) or .stl of the full wing
• OpenScad (free and open source) . Does not support layers during export but can save .dxf  (profile and cutouts in the layer 0)

remember :

• layer 0 : contains the profile (and may contain all the cutouts)
• layer 1 : contains the cut outs attached to the intados (optionnal)
• layer 2 : contains the cut outs attached to the extrados (optionnal)
• layer 3 : contains the synchro points on the profile (optionnal)

Remember also to choose the "polylines" option (lightburn and LibreCAD) to get best result (see below why)... currently the software does support :

• lines
• ellipses
• circles
• arcs 
• bulges
• polylines,  lwPolylines
• Splines (if with fitpoints) 

also, but depending on CAD software who produced the file, the precision may be degraded (I do use ixMilia dxf library to read dxf. A warning will be pop up if "unsupported entities" are found during import) ...

For simple wings WiHoWi can import or convert .dat file format into .dxf Polylines (High Density) 

This is by far the best way to to get high resolution profiles and get the best result from your foam cutter. Your profile will be "faceless"  and so will be your wing...

to be compared with the red dashed profile below (.dat to Polyline) :

When importing a .dat file, the default/only option is "High Density polylines" as explained above. This means that even poorly defined profiles will be "splined" before being converted to polylines.

When importing a .stl file, the wing is imported "all at once", the full geometry is preserved. So that wing length, wash out angle, dihedral, chords are directly read from the .stl. They can of course be modified if needed. ...