Indoor Flight Model

Indoor Flight Model with wing span optimized to the printing plate size of Prusa MK3. 3D printed parts in PETG, resol. 0.15mm.  Besides of optimizing wing span to the printer bed the scope of the project was to fully avoid the use of carbon fibre parts (which would reduce the weight but increase the cost of the plane significantly).

Flying properties:

Gliding ratio (without propulsion): 1:4

Take of weight (TOW): 42gr. (incl. rubber band propulsion)

Wing span incl. mid section: 525mm

It was a challenging project to design a 3D printed indoor flight model which has acceptable flying capabilities. V1's flying properties are ok to start with, however it has been designed and produced to experience further space of improvement in terms of weight reduction/gliding ratio and flight duration.

Maiden flight happend successful without damage to the plane nor anybody else arround (humans and cats). Several following test flights are indicating how to improve the  design for better flight properties (weight reduction, wing configuration, center of gravity/trim). 

To assemble the plane besides of the 3D printed PETG parts following other material have been unsed:

Cover of the wings: approx. 0,3m3: Mylar film 36 Micr. (other plastic film or paper will do the job as well) and approx. 2m doublesided adhesive tape 5mm to laminate the wing cover to the wing skeleton.

Steel wire diam. 1.5mm approx 150mm: wing assembly, assembly of the foldable propeller, fixation of the rubberband, assembly (glue reinforcement) of the front and tailsection.

Rubber band 1x1mm diam. 45mm for propulsion

Glue to mount the nose to the body.

PTFE tube 3/1mm (AD/ID) - approx 10mm (propeller bearing)

Glas bead diam. 3mm with hole, to avoid friction of the propeller

Two medal bolts M2, 5mm to screw the foldable propeller blades to the spinner.

To trim the plane there is a track on the middle section to moove the wings for optimize longtidual trim (very slight front trim recommended). Use Scotch Crystal clear tape (or similar) to hold the wings to the body for test flights and trim optimization. The design should have engough savety margin in its construction to avoid damage for first trim flighs (which usually end with stall  landings). For any case avoid pets in the indoor flight area and the landing zone! Let me know how you would improve the flying properties. Allways happy to learn. Enjoy printing!