I am pointing out a somewhat uncommon end mill that I find useful in pattern making. It is tapered about 2.4 degrees on a side for an included angle of 4.8 degrees. (I know the write-up online says 2.8 per side but that has to be a typo if the overall angle is 4.8) Anyway I find it very handy for use in my milling machine for profiling pattern parts. I used it this morning to profile a pattern for the runner in my 30" square mold. I like the idea that it establishes the draft angle accurately and works into corners easily where using a tilted bandsay can be cumbersome to say the least. It is solid carbide so it should stay sharp a very long time. It appears to be well made and is quite sharp. At 17 bucks I think it is quite reasonably priced. https://www.amazon.com/dp/B07B93TVQ1/ref=dp_cerb_2 Tapered Ball Nose carbide EndMill / Cone Cutters with 1/4 Inch Shank 2 Flutes, H-Si Coated Ball Raidus: 1.5mm, Flute Length: 1-1/4Inch, Overall Length: 3Inch, Single Side Angel: 2.8Deg The Tapered Carbide Carving bits suit For CNC,Engraving Carving 3D machine. For HRC 55 Carving and machining hard wood, solid wood, partical board, plywood, stainless steel,titanium alloy etc High quality tungsten carbide and coat. Long service life and less wear. Denis
I am using it to cut wood, so I run it as fast as my mill will turn which is 2750. If I were cutting aluminum I would run it around 1000 or so. It could also be run in a router for wood and then would likely turn 10000 RPM or more. If I were using it in my router, the router would likely be in a router table. Whatever tool is used to spin the cutter, using a stream of compressed air to blow chips out of the tool path helps cutting life and efficiency. Same effect can be obtained with a vacuum and is my preferred option. Denis
I use a 6mm 2-flute carbide with straight flutes. It has a 10 degree included angle and runs about 16000 rpm in my CNC's Dewalt 611 trim router. I do all of my pattern profiles with it. I also have a few spirals similar to yours but haven't tried them yet. Pete
This is probably my favorite endmill for my CNC router: www.amazon.com/JERRAY-Carving-Tapered-tungsten-Carbide/dp/B015C61XX4 4.82° included angle with a 0.5mm tip and 1.25" cutter length. Drafts things perfectly with a nice small radius at the bottom for a sharp look. It has held up very well for many projects. The tip being super fine makes some jobs long but it produces a lot of detail on 3d carvings, and is exceedingly useful for making small plaques - it can really get inside of some small letters. Admittedly not small enough for a lot of the things I'd like to do but that's one of the limitations of subtractive machining. Edit: The pattern for this project was finished using this endmill: http://forums.thehomefoundry.org/index.php?threads/everdur-casting-project.718/
Thanks for linking the thread Rocketman. It was a great read. I know sometimes you can't get away with it but I've found that you can often make the interior cavities in letters and sometimes the pinch points between letters a little shallower (or sometimes a lot shallower, relatively speaking) on the pattern in order to get a clean pull with little obvious effect on the casting. The dates on your casting look like a real challenge. Pete