some_42s

_42_no2_mit7_50_34_51_round.stl

Description on q-tri.org
Fourdy-Two No. 65
with octagon magnet holes for
magnets height 3mm diameter 5mm

_42_65_tankerplus_H30bev3_5mmoct.stl

Description on q-tri.org
Fourdy-Two No. 66
with octagon magnet holes for
magnets height 3mm diameter 5mm

_42_66_tankerminus_H30bev3_5mmoct.stl

Description on q-tri.org
Fourdy-Two No. 67
with octagon magnet holes for
magnets height 3mm diameter 5mm

_42_67_torpedoplus_H30bev3_5mmoct.stl

Description on q-tri.org
Fourdy-Two No. 68
with octagon magnet holes for
magnets height 3mm diameter 5mm

_42_68_torpedominus_H30bev3_5mmoct.stl

all simplices which can occur in a conform trianglulation of the set of corners of a cube

Cube triangulation simplices

in "Dn" n gives the number of internal faces of the simplex
34 stands for magnet hole depth 3.4mm
31 stands for magnet hole diamerer 3.1mm
bev2 stands for a bevelling "radius" of 2mm

D2p_3431_bev2.stl

This is a set of all 66 octiamonds, a well known puzzle concept consisting of all different pieces which you can create from eight equilateral triangles if you glue them edge to edge in the plane. There is a piece number engraved on one side of the piece using Michael Dowle's numbering system, cf. footnote. Octiamonds are of course not invented by me. Search engines lead you quickly to sites describing the puzzle concept. I print them in 11 different colors grouping the following pieces together:

    (21,24,32,37,60,66)
    (7,14,46,49,51,58)
    (1,30,31,42,52,55)
    (6,19,35,43,47,64)
    (2,33,36,39,48,59)
    (10,20,22,26,53,65)
    (18,29,50,54,61,62)
    (5,12,13,38,56,57)
    (16,25,27,28,34,40)
    (9,11,15,23,44,45)
    (3,4,8,17,41,63)

Each set of pieces of one color can be combined to the same geometrical shape (a discovery of Patrick Hamlyn, cf. footnote) such that you can stack them in 11 levels. I have also designed a box which uses this format. The orientation of the engraved number is chosen such that the number is face up when putting the pieces into the box. This together with the colors makes it comparatively easy to get the pieces back to the box.

You could also print all pieces in two colors (half the layers in one color each) and so allow for a second colour scheme allowing for a second way of stacking (e.g. 6 layers of 11 pieces, cf. the last photo); in most cases the orientation (engraved piece number face up) would then however work only for the first color scheme described above.

I have printed the pieces and the box both in PLA and PETG. For the box cover PLA might be superior due to better bridging.

footnnote: facts about octiamonds quoted from mathpuzzle.com/octiamonds (downloaded 13th March 2021).


box of all 66 octiamonds

Octiamond_box.stl

an octiamond with No.1 according to Michael Dowle's numbering system


octiamond_eng_no1.stl

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