感謝提醒。我有聽說這一條的更新。但看到的中文解讀多少有些不同。以下摘自TAMIYA英文官方網站: In the following cases, it will be considered that the original part shape is NOT identifiable: ※Modifications to the shape of carbon plates, FRP plates or metal parts (including modifications to shaft, pin or roller shape). ※Using rollers and parts in prohibited combinations (putting plastic rings on rollers that do not use them; using plastic ring rollers without ring; using combinations of different sized rollers; cutting off one end of double rollers). ※Attaching HG aluminum setting boards, setting gauges and pinion pullers to the car. 可以看出,這條的更新是基於切割使 original part shape is NOT identifiable。在ROLLER這邊舉例是說putting plastic rings on rollers that do not use them; using plastic ring rollers without ring; using combinations of different sized rollers; cutting off one end of double rollers。主要是針對把零件的外形改到NOT identifiable。但並沒有說導輪與軌道的接觸面不可以打磨。所以我暫時並不同意您的觀點。 希望有懂日語的車友可以根據日語規則做個解讀(畢竟即便是官方的英文版也有可能翻譯錯誤)。 最後,再次感謝您的留言。這是我以前沒仔細研究的規則變更。