Instead of incorporating sine plates on a vertical-spindle rotary surface grinder, I use cold-rolled steel blocks to set up large die segments needing to be ground on angles. These blocks, with tapped holes for 1/2 or
5/8-in. bolts, mount to the segment via its existing holes. I then mark one surface to be kept square with the tapped holes, turn the segment upside down on the grinder's magnet, and grind the blocks. This positions the segment's cutting surface parallel with the blocks. After turning the segment over, I grind it.
Having a selection of such reusable blocks makes the grinding operation fast and provides an excellent regrind, even on round or odd-shaped segments. It also eliminates having to align angles.
Idea airs-out turning
My idea evolved from turning stator housings for automobile alternators. Stators consist of several stacked plates riveted and glued together with copper-wire windings around them. After winding, stator O.D.s are turned using carbide inserts. The problem was generated heat shortened tool life, but emulsion-type coolant couldn't be used because of cleaning issues. So I tried compressed air.
After fitting suitable guards and mounting air-hose pipes, I directed the compressed-air stream to cool the cutter and divert chips away from the stator while turning. This eliminated overheating and increased tool life by 3 .
Pick the winning Practical Idea!
Select the best Practical Idea in this issue by circling the associated number on the reader service card. Winners receive an award of $100. An honorarium is paid for each item published in this column. Submitted ideas are subject to editing, and sketches will be drawn to conform to AM's style and format. Submission of clear, close-up photos is encouraged.
Send material to Practical Ideas, AMERICANMACHINIST, Penton Media Inc., 1300 E. 9th St., Cleveland, OH 44114-1503. Please include your name, address, zip code, and Social Security number.
Winner for April 2005: John Greene & Steve Earle,"Lathe work on a mill," p. 74.