FlexFlexRail

Mod of FlexRail with Knobs on one and both Side.

I have the Idea to use my empty Filament spool for building another Track
for the ball track

Add a "Distance" Part so that enough height between two FlexFlexRail.
This Part is similar to ft 38246 "Bauplatte 15x15 1Z rot" but with 12x10mm
(and a Bad Knob 8-( )

Fischertechnik Steel Balls have a diameter of 12,7 mm.

The Knobs are longer so that no Support Structure is needed
but round knobs are better for slope of the Rail