To accommodate medical, electronic and instrument manufacturers, The Dunham Tool Company has added 1C and 3C collet-capable spindle assemblies, as well as 1C and 3C collet actuators and chucks to its product offering. Also now included are 5C, 16C and 3J models to permit the use of a broader range of collet sizes.
Each Dunham spindle/headstock model can be used as original equipment in lathes, grinding machines and special-purpose machines, in addition to bench mounted to replace worn secondary workheads on lathes or cylindrical grinders. Accepting collets directly into the spindle without necessitating additional collet fixtures, spindle capacities now range from 1/64" (1C) to 1-3/4" (3J) for OD holding; 3/4" to 6" for step chuck OD holding; and 1/4" to 6" for ID holding with expanding collets.
Models are available with plain nose, 4-degree taper nose (which accept closing rings for Hardinge step chucks with diameters as large as 6", and American Standard spindle noses A-3, A-4 and A-5 for accurate mounting of jaw Chucks and custom fixtures. The company’s spindles are rated for speeds as high as 6,000 rpm.