What is a Multi Spindle?
Although you are probably familiar with the principal of the multi-spindle automatic lathe, a few words of explanation may be helpful for those who do not know the machine.
Multi-spindle automatic lathes—or "autos" as they are universally known—provide the means of producing turned metal components in medium to large quantities compared with single-spindle machines. Their function is similar, but there are differences.
On a single-spindle machine, the various tools required for the sequence of operations are fed to the work consecutively. On a multi-spindle auto, the various cutting operations are divided between the number of spindles available, and all cutting operations are effected concurrently. Each spindle position (six on a six-spindle machine, for example) is tooled to produce consecutive stages in the production of a component in a continuous cycle so that at each indexing of the machine a completed component is produced.
Some classes of work are more suitable for multi-spindle production than others, and in such cases even faster times can be achieved, but the reverse condition can also apply. A workpiece may possess certain features which slightly reduce the comparative production rate, so no hard-and-fast rule can be quoted without an understanding of all the conditions involved.
Multi-spindle autos have been built by Wickman with four, five, six or eight spindles. Bar autos produce components from round, hexagon or square bar stock and chucking autos machine components from castings, blanks or pre-turned parts, which can be fed into the machine manually or by automatic feeding equipment.
A feature of all Wickman multi-spindle machines is the "no cam change" mechanism, patented by the machine designer Reg Dixon in 1934, by which all the cross slide, independent slide and turret strokes can be changed in a matter of moments without the need to design, manufacture and store special cams. There is, in effect, an infinite number of cams built into the machine as standard. The economics of multi-spindle automatic operation were transformed by this feature, which gave the Wickman machine tremendous advantage over competitors. The multi-spindle auto was no longer for large-batch production only. Overnight, medium and small batches could be economically produced on the Wickman.
Production engineers soon became aware of the advantages (i.e. reduced cycle times), which could be achieved by the use of free-machining leaded types of steel, and where applicable, carbide tooling.
