I need to order some ceconite, glue, and paint to cover the wings so while that arrives I did a bit of work to tidy up the inside of the doors. The Wittman plans give the basic outline of the doors and the door latches but no information on internal finishing. My intention is to cover the inside of the doors with fabric but that left the issue of how to tidy up round the door latch mechanism.
I started off by making two box structures,
each out of two pieces of aluminium to cover the mechanisms and then pop-riveted these to the door frames. Next these were covered in ceconite. The leading edges of the doors had had the aluminium skins bent round them and the gaps were filled with a slurry of vinylester resin and microballoons (I'm only allergic to epoxy resin). The same mixture was then used to bond small strips of wood left over from the wings to the wing skins. This adds almost no weight and should reduce any risk of "oil-canning" in flight.Whilst I haven't been building the Wittman over the last few months, I have been building myself a 3D printer! This is now fully debugged and prints very reliably. I use Google Sketchup to draw the 3D part and then this is saved as a .STL file. Slic3r is then used to convert this into the gcode instructions for the printer which is driven using Pronterface. Gcode files can also be saved on a microSD card and printed directly from a card reader built into the printer electronics (Ramps 1.4 with Marlin firmware)
The printer is a Prusa Mendel V2 design with additional cross bracing and home designed filament spool holders and LCD display mount. This was used to "print" a pair of door handles and backing plates in white ABS. Once the ceconite for the wings arrives, I will also finish the insides of the doors and then they will be ready for final painting. Another little job ticked off.
