This is something I cooked up after getting interested in negative rake scrapers, mainly for cleaning up tearout or tool marks on the inside of bowls. DSC_0674_2.jpgDSC_0677_2.jpgDSC_0679_2.jpg The bowl in the pic is a roughout that I mounted up as a prop just to show the shearing cut (mentioned below), so don't look for a smooth surface, there isn't one. At times I have used a curved skew as a scraper, but always had to worry about the point at the end the curve, and would often have to come uncomfortably close to that point when negotiating the curve of the bowl. I basically just eliminated any points, and have a varied curve, any part of which can be used for scraping, depending on what is needed. The nose can be used to take the tiniest cuts near the rim, where greater contact would cause chatter, or the more gradual portions can smooth out ridges if there is enough thickness to support the longer edge contact. It can be used at a variety of angles, without risk of a catch, as long as it is flat on the tool rest, and due to the negative rake, there is no need to hold it in a downward orientation, nor angled so that the edge is contacting the tool rest, as in a shear scrape with a normal scraper. One can obtain more of a shearing cut by orienting as in the photo, which I'm guessing is at a good 35* to 40* angle to the bed of the lathe. This would be disastrous with a regular scraper, but I haven't been able to actually cause a catch so far with this tool flat on the rest. By dressing both sides each time you sharpen, you merely have to flip the tool over to gain a fresh edge, so there is less time running back and forth to the grinder. You just have to remember which side of the tool to sharpen to get the burr on the desired side, left or right, depending on whether you are using it on the inside or outside of a bowl. It also works well with spindles. After making this from a parting tool that came with my first turning tool set (from Harbor Freight), I saw something roughly similar that Cindy Drozda sells, but hers is more of a round nose scraper that still has points on either side of the curve. I've never seen anything exactly like this, where there are no points at all to worry about - not to say that someone else hasn't done the same thing, just that I haven't seen one. I'm sure that I could patent this and make millions of dollars selling them on TV infomercials, but out of the goodness of my heart, I'll just put it up here for free, and let y'all make your own. This one is 5/8" wide. I have found it very useful indeed. Dan
Reply With Quote
