How do I get a better finish? Use a face mill or a fly cutter?Answering this question is easy. Go with a fly cutter every time. Get a single cutting surface with a fly cutter. Use a blade larger than the work area for a finishing cut with a single pass. Every finishing pass you make decreases the finish quality. Remove all cutters from your face mill except one and convert your face mill to a fly cutter. Or, just start with the right tool in the first place.
Can you fly cut aluminum?Yes, but you must use the right cutting blade. Remember, aluminum is soft. Use a hard cutter for the best result. How do you grind the bit? Never forget the geometry of the cutter. The end of the tool always does the cutting. Grind the rake into the end of the tool. It's the bottom of the bit that determines the surface smoothness. Are feeds and speeds different? Just use your standard shop software to calculate feeds and speeds. Fly cutters usually run at lower RPMs. Only your software knows for sure. As with any other job, just rely on your software for proper feeds and speeds. Software is very important.Can you fly cut to quickly remove material? Use your face mill first to remove material quickly. It does this job better. You'll get deeper cuts and faster chip removal. Once all material is removed, then make that final fly cutting finish. Does tramming matter? Just if you care about results. This question usually comes from someone noticing a dip in the finish. The tool isn't the problem. The tool set-up is the problem. Make sure everything is trammed and up to snuff before you make the first pass.
What makes a good fly cutter?The real questions are who makes a good fly cutter, what makes it good, and where can you get it. The answers are as follows:
Big Diameter Fly Cutter is BestMinimize the number of passes by maximizing the size of the tool. Bigger cutter equals fewer passes resulting in better finish. That's the formula for a good fly cutter. The Tool Company carries large diameter sizes to handle large cutters. Repeat after me the flycutting mantra "The larger the cutter, the fewer the passes. The fewer the passes the finer the finish." Bigger is better in flycutting!
Stability and Balance
balance and stabilityJust like the kids walking those train tracks, you need stability and balance to get where you are going. Finishing cuts need maximum stability and balance. You'll get that with a Tool Company fly cutter. Their fly cutters have the larger 1/4-20 alloy set screws. So, you get better blade stability. Because they are balanced, feel free to run at whatever RPMs you need to achieve your goal.