I just wanted to share the shaft drawing with you which I made.
I do reverse engineering from the original one and extedned it for 20mm, added groove hole for 3x22 key
meh, i have do this finally
Turnigy sk3 6374 shaft - extended.SLDDRW (182.0 KB)
Turnigy sk3 6374 shaft - extended.SLDPRT (121.8 KB)
Turnigy sk3 6374 shaft - extended.STEP (55.3 KB)
Turnigy sk3 6374 shaft - extended.PDF (88.3 KB)
Turnigy sk3 6374 shaft - extended 3DPDF.PDF (12.8 KB)