New work piece

This week we got a new work piece as shown in the photo above.

Similarly, we grind the parallel surfaces first. But this week I made a big mistake! I was supposed to grind 0.12mm, which 120 microns on each of the parallel surfaces to a dimension of 16.55mm and to reach the total width of 36mm and also to achieve symmetry. However, after I ground the first surface and took out the work piece and checked its dimension, I forgot which side I had ground and which had not. I just simply place the ground side on top thinking that if was not ground yet. Then, when I took the measurement again, I only realised that I ground the same side! Now, one side is 16.44mm which was out of dimension already! And I could not grind the other side to the same dimension. It was because if I did so, the total width of 36mm will be affected. Luckily, Mr Teng did not scold me but just said, "Never mind. Now, what you need to do is grind the other surface to keep the total dimension of the width, just ignore the symmetry." So, I did what he told me but still felt very sad because of my silly mistake.