Quote Originally Posted by routercnc View Post
As Mark points out I am running bearing races directly onto Ali profile, but I always knew it was a short term solution and a small witness mark is appearing on the profile where the bearing runs over it. Not the best long term solution, although a hardened running strip might give better service.

Stray dust and chippings do get engrained on the top ali surface,
Would you say it's the dust build up that's is causing the witness mark ?

Phil