three work plates and three detent positions for turntable arm 200 making it desirable for turntable arm 200 to rotate 120 degrees when indexed to achieve 120 degree rotation the stroke length of indexing piston 268 radial position of pivot block pin 270 must be considered relative to the placement of indexing cylinder bracket 266 on the folding group support arm 40 angular index rotation of 180 120 90 72 or 60 degrees could be achieved by suitably modifying component parts and providing turntable arm 200 with 2 3 4 5 or 6 work plates and by providing a suitable number of upper turntable disc locking bushings 262 and turntable locking bushings 226 as best seen in fig1 and 6 a double acting pneumatic dual piston flat cylinder is mounted as clamp cylinder 272 clamp cylinder 272 is bolted or otherwise anchored to a flat side of clamp plate pivot block 250 with clamp pistons 274 downwardly extending clamp support 276 is affixed to the lower surfaces of clamp pistons 274 clamp 278 is screwed or otherwise detachably anchored to clamp support 276 clamp 278 is a flat piece of metal or other suitably rigid material slotted in the sewing pattern in the preferred embodiment where the second workpiece.