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====== Digital Rose Engine ====== This is a work in progress. I completed the first iteration a couple of years ago, finished some pieces, and then moved on to other things. For a while... A little history. This photo shows guilloche enamelwork. It is a technique that probably originated with woodturners and was then famously incorporated into precious metal work by the Russian jeweler Faberge who added clear vitreous enamel coatings and used the technique in many of his famous eggs that were presented to the Russian royal family. {{::firstpattern.jpg?100|}} The same kind of patterning is often seen inside the more upscale (mechanical) watches and clocks. Through the early to mid 1900s the engraving was usually done with a variation of a "turning engine" that came to be known as the rose engine. One is pictured here. The acorn-looking white thing to the right is the piece being worked on. The machine is essentially a slow-turning lathe where the brass camwheels in the middle area push the chuck that holds the workpiece off center in a repetitive and reproducible manner. And then there is a ton of stuff for indexing and depth control and who knows what else. There are refurbished machines sometimes available for large pricetags and I believe a company making a modern version of the equipment. But where's the fun in that? My friend Bill (who taught me silversmithing and get's himself and me into all manner of trouble) decided he wanted to build his own. From scratch. And after he got a basic prototype working he brought it in to the old studio to demo it. The cam wheels push a rocker box back and forth, and as you can see from the pictured engine, every time you want a different pattern you have to create a new camwheel (Bill's first camwheel was hand-cut from lucite and was a project in and of itself). And it seemed like an obvious thing to propose using an arduino and a motor to push the rockerbox back and forth with a lot more flexibility. (Bill has since discovered that the technology has been somewhat preserved by the Society for Ornamental Woodturners and plans for various cam designs are available, but before we know that a digital test system to figure out how to eventually design the cams made sense). And of course that led to asking why not put all 3 motions (radial, Z, and rotation) under computer control? Bill said "you should give it a go" and I was dumb enough to say "sure, why not?" I was fortunate enough to have the guts of a sherline 3 axis platform that eliminated the need to figure out a lot of the mechanical side of it. And I had a rotary table that came with my Taig mill. After a few false starts I had a version running with a spring-loaded pen holder and some very crude code that drew this first image in Sept 2013. Teaser photo: {{:guillochependant1.jpg?100|}}
