[THE GITS]

Once we are satisfied with the straightness of the temporary datum we may proceed too accurately square off the top surface where our track will eventually reside. Of course this may easily be done with a bench plane but as we have a surface planer then the easy route was taken. The fence or guide must be checked beforehand, then make sure as the wood is passed over the revolving cutter block that the datum surface is pressed firmly against it. Again after this procedure we must remove the rippled machined surface with a few light passes of the bench plane. We also check for the accuracy of this squared surface. When completed the surface is given an edge mark to denote it as a reference surface. These datum or reference will become the only surfaces that we will be allowed to measure off in the later staged so they are important to get them correct and true.

Again once we are happy with the previous step we can turn our attention to the underside of the gun. This again must be squared off so that it is parallel to the top surface. We can do this either by marking both sides with marking gauges and planing down to the marks with a bench plane, or we we can use the thickness planer to quickly create the surface. This is of course the route we took as can be seen in the photograph below.