This just came out and I thought I'd share it with you guys. I've written lot of articles for Home Shop Machinist magazine over the years and this is a four part how- to-build-it series starting this month. The tool is an aid toward aligning machine tool ways when you scrape them, its my design but is patterned after a commercial one unavailable now for decades (It think mine has a number of improvements) . Fairly esoteric, but it generates a good bit of interest as scraping is a very cool thing in that with fairly simple hand tools you can take best of breed machine tools and restore the bearing surfaces to their original accuracy or better. Tenths of thou territory (microns for you guys across the pond ). Probably not many here into machining, but its my main hobby and what got me interested in clocks and watches. Cheers