A Handwheel Dial for the Mini-Lathe

摘要

The extension or input shaft is turned from ENIA Pb. A piece is gripped in the 3-jaw chuck with sufficient protruding to make the complete shaft and the end is faced and centre drilled then supported with a running centre if you have one or a standard centre with suitable lubrication. Take a skim over the outside diameter of the bar reducing it for the entire length of the shaft to the outside diameter of the gear; the sizes being 19.68mm for an imperial dial and 21 mm for a metric dial. Next reduce the diameter to 17.2mm for 40.9mm being sure to form the undercut in the corner and reduce the diameter further to 14mm by 25mm long with another much smaller undercut. The shaft is then still further reduced to be 0.2mm oversize on the 8 or 9mm diameter by 23mm long and an undercut in this corner is optional but I find the provision of an undercut makes life easier when sizing this portion of the shaft.