FILENAMES: shaper_dovetail.txt shaper_dovetail_00_tool.jpg shaper_dovetail_01_tool.jpg shaper_dovetail_02_tool.jpg shaper_dovetail_03_tool.jpg shaper_dovetail_04_tool.jpg shaper_dovetail_05_setup.jpg shaper_dovetail_06_setup.jpg shaper_dovetail_07_setup.jpg shaper_dovetail_08_setup.jpg shaper_dovetail_09_cutting.jpg shaper_dovetail_10_cutting.jpg shaper_dovetail_11_cutting.jpg shaper_dovetail_12_cutting.jpg shaper_dovetail_13_cutting.jpg shaper_dovetail_14_results.jpg DESCRIPTION: These are photos of a shaper dovetal cutting tool bit and usage. Posted by Pete Somebody . Pete provided the following description: ================================================================= FILES: shaper_dovetail_00_tool.jpg -- shaper_dovetail_04_tool.jpg: These are a couple of views of the cutter I made for the dovetail work. It's a 3/8" x 3/4" HSS tool, 4" long. Nice and rigid, which is important because of the odd angles and long tool overhang that's sometimes necessary in dovetail cutting. It does take a long time to grind the tool, though. Most relief and rake angles are about 8 degrees. Since I was cutting 60 degree dovetails, I made the point angle 55 degrees. In a couple of the pictures, notably in 04, you can see that the butt end of the tool is colored. This is just a copper coating for marking out lines on it. I have much better results grinding a tool this size if I mark it out correctly first. For most markup work I use a Dykem marker, but Dykem doesn't stand up well to the heat, handling, and repeated dunking of a tool grinding session. I've started dunking unground cutter ends in a solution of copper sulphate for a minute, which puts a copper coating on the steel. This takes the markup lines nicely and holds up pretty well. This tool worked well. I found I could make it chatter if I really wanted to, but not easily. Used sanely, it's good and rigid. shaper_dovetail_05_setup.jpg -- shaper_dovetail_08_setup.jpg: These are four views of the way I set up the machine to make the cut. The tool slide is set over at 60 degrees, carefully, using a good protractor. The tool is set to leave clearance on both faces of the dovetail being cut. The dovetail is 60 derees and the tool is 55, so there's not a lot of spare room. Note, by the way, that these angles mean that the tool only cuts on its tip, not its edges. I didn't set the vise up well: I should have set it around so that the movable jaw was perpendicular to the ram's travel. This would have ensured that the work stayed put rather than being knocked out of the vise by the tool. I didn't bother, and paid for my neglect before the project was through. 05 shows the tool in place on the shaper, ready to cut. You can see that in some cases it'll be tough to find room for everything: if you're not careful, the tool slide will stub its toe on the work. To avoid this, you may have to raise the tool slide up away from the work surface, and then extend the tool a good long distance to reach the cut. Times like that, flex and chatter could cause real problems. This is why I used such a heavy piece of HSS to make the cutter. It's a workable solution. 06 is a closeup of the same setup. If you look closely, you can see the scribe line showing where the edge and bottom of the dovetail will be when it's done. 07 and 08 show the tool in the cut and the clearances on both faces being machined. These two shots are very similar, but the former shows the tool well and the latter gives a better view of the work itself. shaper_dovetail_09_cutting.jpg -- shaper_dovetail_13_cutting.jpg The cut itself. 09 is the cutter being lined up to take the next bite out of the growing dovetail. 10 through 12 show the cut itself enlarging the dovetail. As you can see, it's a fairly hefty cut. In these pictures I'm using the hand downfeed on the toolslide to accomplish the cut, giving the wheel a little crank during the ram's return stroke. I guess I was taking about ten thousandths per stroke. (I'm not sure about that: I wasn't really paying attention.) 13 shows the bottom of the dovetail being cleaned up, using a horizontal cut and the power feed. shaper_dovetail_14_results.jpg I've left this one in color. I usually upload grayscale images to save space on the server, and color doesn't usually add anything anyway. In this case, though, the color is necessary so you can see what's going on. The yellow thing is a glass rod borrowed from my wife's worktable. I just held its end up to the freshly cut dovetail to see whether the cast iron would show its reflection. As you can see, it does so pretty well. The finish inside the dovetail is nice and smooth.