In the first video, Marc talks about the thousands of tiny cutting teeth that can be used to improve finish and to make the part more accurate.
In the pics I’m trying to show the face mill marks and a slight lip on the angle plate finish which shows the mill used to process this was not perfectly trammed. The high section came off in the first pass at about .002” depth, the second and finish and spark out is all it took.
I decided yesterday I would surface grind, then scrape this surface plate I’ve had for a year or so.
Im using the “Challenge”, angle plate I scraped at Richard King‘s class last April, in Vacaville Ca., as my right angle clamping reference. The SG is a 1966 Brown and Sharpe, 618 Micromaster, fully automatic.
Once I finished the piece, I don’t think I need to scrape it. I plan on using it on my mill for fixturing/clamping.
As you can see, by using the machinists square, it’s pretty darn square and flat. I can always do it later.
This took about ten minutes.