Named Fog — hiding its true intentions behind a mist. Kiri is a ground-up custom Wankel rotary engine built on RX-7 proportions, developed entirely through 3D printed iterations. The powerplant for Project Rain-Drop and the foundation for everything that follows.
First geometry printed. Housing confirmed printable. Gears too small, caused binding. Rotor geometry mismatched. Motion test: 2/10. Confirmed the geometry was printable and identified where to improve.
↗ View ReportGears removed to test rotor clearance independently. Confirmed rotor and housing were fundamentally different geometries — not built from the same mathematical foundation. Required full redesign.
↗ View ReportFull rotor redesign. RX-7 K=7 proportions locked in. R=28mm, e=4mm. First successful rotation and full orbit achieved. Smoothness 7/10. Rotor drifts without gears confirmed.
↗ View ReportFull redo using corrected parametric equation. Gears introduced for first time — module 0.80, 20/30 tooth, 3:2 ratio. Good mesh, minimal slippage. PLA friction identified as major issue requiring lubrication.
↗ View ReportEccentric shaft and hand crank added. First complete mechanical assembly. Rotor tracked epitrochoid path under hand crank power. Kiri moved for the first time. Gear slipping under extreme load noted.
↗ View ReportFilleted edges, cover plate with window, 4-bolt mounting. Silicon grease introduced. Shaft clearance relief added. Smoothness 8/10. Modular design proven — cover reprinted without touching other parts.
↗ View ReportYM2707 4.5VDC motor, 5:1 external gear reduction. Arduino soft-start code. Battery powered operation. Motor driven rotation confirmed after identifying hand crank obstruction. Silicon grease on all moving parts.
↗ View ReportFull rear plate 4-screw motor mount. First confirmed sustained motor driven rotation achieved. Eccentric shaft identified for full redesign. Brass inserts required for grub screw. Looked great at speed.
↗ View Report