assembly 18 see fig9 operably secured to the sub base 12 and the tailstock body 14 slidably drives the tailstock body 14 along the guideways 16 a limit switch 20 operably secured to the sub base 12 cooperates with trip dogs 22 24 and 26 that are secured to the tailstock body 14 to control the sliding movement of the tailstock body 14 relative to the sub base 12 the tailstock 6 has a quill 28 that engages the work piece 10 thereby to support the work piece at its remote end from the work holder 8 an adjustable stop block 30 operably secured to a threaded rod 32 and a hand wheel 34 provide a solid stop for the tailstock body 14 for delicate parts or for safety in case the hydraulic controls malfunction the trip dog 22 is fixedly secured to a skirt 36 that is fixedly secured to the tailstock body 14 as best shown in fig2 and 6 the trip dogs 24 and 26 are moveable along respective slots 38 and 40 clamp assemblies 42 and 44 are each associated with the respective trip dogs 24 and 26 to permit locking each of the trip dogs on any desired point along the respective slots 38 and 40 each of the clamp assemblies 42 and 44 comprises a c shaped bracket 46 and a thumb screw 48 a spacer plate 50 operably secured to the skirt 36 cooperates with each bracket 46 and thumb screw 48 such that the respective trip dogs 24 and 26.