Swedish style Mjolnir (Thors hammer)
Mjolnir (The crusher / pulverizer) Possibly representing the beating heart, general life force. Likley evolved from the axe of Perun, which evolved from a flint arrowhead or stone axe.
Sun cross, representing the sun and the four seasons.
Valknut / Hrungnir's heart (prefer the theory that it represents a proud heart refering to the story of Hrungnir)
The remaining triangles have been found on several viking age Mjolnir pendants.
0.15mm layer height
-78° angle (symbol face up, hammer head touching print-bed)
0.4 nozzle should do fine, just print at an angle with supports for best result.
Tinkercad for general shapes, Vectary for smoothing