Harold Hall

Workshop Projects


Next, place the part in the milling machine vice using the line on the end, just made, to assist in positioning it, reduce the thickness to 15mm, Photograph 9. The viewer may be puzzled by the lack of machining lines, actually, I had removed the part from the vice and found it very marginally thicker at one end to the other. As a result, I placed a file in the vice and rubbed the cutter holder on this applying more pressure at one end to correct the error. Having done that, I realised I had not taken the photograph, hence the lack of machining lines. The photograph also clearly shows the complexity of the part that has been produced relatively easily. Except for shaping the ends, all that is required is to drill the three holes for the cutters, Photograph 10, and the tapped cutter fixing hole.


Measure the thickness of the cutter holder between the flat and curved surface and from this determine the necessary thickness of the gib strip (4). Cut a slice from the piece of material prepared for this and mount it in the vice, similarly to photograph 9, and machine to the required thickness. Having done that, lightly file a small portion away from the corner that will eventually have the cut out C made. The purpose of this is to ensure that the gib strip is assembled the same way round for the remaining operations until at such time as the cut out is made.


Assemble, body, cutter holder and gib strip (correct way round), again using a grub screw in the M6 thread to ensure alignment and fit one M4 grub to secure the parts. Drill through the other tapped hole to establish the position of the first hole in the gib strip. Use the same size of drill that you used for tapping the hole. Fit and secure second grub screw removing the first and mark the position of the second hole. Remove the gib strip and drill the two 4.1mm diameter holes 3mm deep.


Place the body in the three jaw and make the shank to your preferred size, Photograph 11. With the shank now made, the head together with the cutter holder and gib strip can be machined to produce the final shape of these parts as shown in Photograph 12. This photograph clearly shows the need for the corner of the gib strip to be cut away to make it possible to fit the dial. It is hardly worth setting up the milling machine for this being more a task for the small hack saw and file.