machine flutes
- Thread starter freddygotarf
- Start date
Make up a short test piece, from some scrap steel rod, and try a couple different sizes and depths, to see what you like.
Different diameters of barrel are going to look quite different with the same size and depth of cut on them.
Got a selection of ball end mills on hand, or planning on buying them as required?
Not many went wrong copying success. Got access to a couple barrels you can measure? Width and depth are pretty easy, and if you don't have a set of radius gauges, a set of drill bits will do in a pinch.
Cheers
Trev
Different diameters of barrel are going to look quite different with the same size and depth of cut on them.
Got a selection of ball end mills on hand, or planning on buying them as required?
Not many went wrong copying success. Got access to a couple barrels you can measure? Width and depth are pretty easy, and if you don't have a set of radius gauges, a set of drill bits will do in a pinch.
Cheers
Trev
If you can get some 12L14, or 1137, or 4140 to try this out on, you'd be a long ways ahead.
12L14 is a leaded, free machining mild steel. It cuts very nearly like brass, and is easy on tooling. It does about everything well except weld. Can still be brazed and silver soldered, though.
1137 is pretty commonly used for rimfire and black powder barrels. 4140 or similar, is common for centerfire barrels.
All are fairly well available, whether from a stockist locally, or by mail order in short chunks.
I'd think that you are pushing the upper end of sizes for anything but very shallow depth flutes with the 5/16, or 3/8 diameter cutters.
Cheers
Trev
12L14 is a leaded, free machining mild steel. It cuts very nearly like brass, and is easy on tooling. It does about everything well except weld. Can still be brazed and silver soldered, though.
1137 is pretty commonly used for rimfire and black powder barrels. 4140 or similar, is common for centerfire barrels.
All are fairly well available, whether from a stockist locally, or by mail order in short chunks.
I'd think that you are pushing the upper end of sizes for anything but very shallow depth flutes with the 5/16, or 3/8 diameter cutters.
Cheers
Trev
Ball mills cut pretty hard and impart a lot of stress into the barrel. You are much better off to use a chain sprocket cutter. ¼ inch radius teeth is about the right size for medium to heavy barrels..200 inch radius for lighter barrels. Get one about 2.5 to 3 inch in diameter. You can make your own shaft for it. Smaller woodruff key cutters can be used too but the cut is not nearly as smooth. Run em at 90 to 150 rpm with a good flood of water. Feeds depend on the steel and the depth of cut. Gear or sprocket cutters are not cheep but they give better results than ball mills and will outlive ball mills 10 to 1.
