Abstract: There is disclosed a scroll-type machine specifically suited for use as a gaseous fluid compressor. The machine incorporates an improved rotation controlling mechanism which is extremely simple in construction, several embodiments of which are disclosed. This mechanism does not eliminate relative rotation between the scrolls but limits it to a relatively small predetermined amount. Several novel techniques for contouring the profiles of the scroll wrap flanks to give good flank sealing with the aforesaid rotation controlling mechanism are also disclosed, as are two embodiments of an improved scroll drive mechanism and an improved thrust bearing arrangement. A novel method of machining a scroll is also disclosed.