Fly tying bobbin

A simple bobbin for fly tyiers.
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Besides printed items you need:
* Long M4 screw (hex head). File half of the screw partially so it fits the D shaped hole.
* M4 nut.
* Piece of tube from pencil refill.
* Little wheel cut from rubber foam
* Optionally glass bead (to be glued into pencil refill end so you get almost ceramic bobbin :).