My keyboard's pitch of key switch is 16mm by 16mm. This means there isn't producted keycap for my keyboard. Natural option recently is 3D print the keycaps.

There is some people published keycaps for low pitch keyboards at marketplace on https://make.dmm.com/, well-known 3D print service in Japan. e.g. YKNキーキャップセット(Chocスイッチ 15x15mmキーピッチ用) or Choc 向け 挟ピッチ16mm 薄型キーキャップ（50個）.

I liked YKNキーキャップ but it doesn't contain enough keycaps for my keyboard. I also wanted to keycap same size as kailh mini choc keyswitch, 14.5mm×13.5mm. So I tried to create keycaps using FreeCAD.

My first attempt is applying chamfer to box on FreeCAD but it was boring.

I tried Loft tool found while searching for a way to create better model against sketches I draw roughly and it unexpectedly worked well.