|Tip: Eliminating Dimples|
I think most of us novice turners have problems with dimples at the center of the inside bottom of boxes and other turnings. Here is a simple tool and process that will help to eliminate dimples.
The drawing illustrates the dynamic of a rotating piece as well as the cutting tool in relation to a dimple on the inside of a bowl. Most cutting tools, such as scrapers, only cut top down. As soon as the tool crosses the center point, the cutting edge of the tool is no longer engaged, making it difficult to get a clean cut at the center.
The solution is to make a tool that can cut the wood in both directions, from the top down and from the bottom up. The tool is simply moved to the left and right of the center point of the box or bowl, eliminating a dimple.
Grind the cutting edge of a skew chisel to a round profile like a round-nose scraper. I reground a 1"- (2.5 cm-) wide skew and put a 2" (5 cm) radius on the cutting edge.
In order to keep the cutting edge in the center, I made a toolrest that supports the skew/scraper. The toolrest is made from wood (although it would be better in steel). This way, the tool is always exactly on the centerline of the workpiece.
I use this tool only for finishing, not for roughing out the interior of a box. Take very light cuts, and you will be surprised how easy it is to eliminate the dimple.
~Werner Witek, Appleton, WI