Surface K and surface H

This week we need to grind the surface H and surface K as shown in the diagram above. It was more really challenging. To do so, we put the work piece on the platform of the machine with 3 square blocks, acting as a support to the work piece. This was to prevent the work piece from flying away during the grinding process as the surface of the work piece that was in contact with the platform was too small, so it was not very stable when being magnetised on the platform. After that, we placed the grinding wheel very close to the surface K but it must not touch the surface k and tightened the knob that control the y-axis. This is also the main difference between the technique we learned in the previous week and this week. Normally, we will move the y-axis, so that all the surface is well ground but now due the small surface, but now we need not move the y-axis and just keep the x-axis moving. Then, we started grinding. First, we only ground 20 to 30 microns. This is to clean the the surface in order to make sure that the surface is flat before we could take an accurate measurement and grind to the dimension required. When the required dimension was reached, the value of z-axis was then reset to zero. Without moving the y-axis, the work piece was turned to the other site to be ground in the same way. At this time, we need not measure the workpiece again, we could just grind to the zero value of the z-axis that we had reset earlier. In such way, we could make sure that both side had equal height.