Learning about Feeds and Speeds
When I first started using my CNC router I primarily worked with wood and plastics. I didn’t calculate the cutting parameters but just guessed and eyeballed the whole process. When a cut didn’t worked I manually adjusted the feed and RPM in mach3 until it seemed right. This approach worked pretty well for the first couple of months but when I tried to mill aluminium I quickly learned that metals are not as forgiving as softwoods and plastics. Tool after tool broke and I was forced to spend some time learning how to calculate the cutting parameters.
The couple hours spend on learning how to calculate feeds and speeds turned out to be a good investment. Breaking a tool due to wrong feeds and speeds almost doesn’t happen anymore. But the chance of breaking tools when I’m working with new materials, CAM settings or work holding are still very high.
New Tools
My tool collection starts to grow and I am experiencing some hesitation to use my more expensive tools. Braking an almost $40 dollar tool by a stupid mistake will certainly upset me.
As already mentioned, most of the tools break when I’m testing new materials CAM settings and work holding. Besides that, it sometimes happens that I break a tool with an operation I’ve already done dozen of times. This is usually caused by a typo or a wrong checked box in a fusion 360.
To minimize these mistakes in infusion 360 I started using templates. By using a template all cutting parameters are saved and when you start a new project you can generate your toolpaths out of these templates. It saves a lot of time and the chance of making a mistake is very small.
Low budget tool Library
When I’m testing new materials, CAM settings and work holding I stick to using only low budget tools. Tools that are good enough to use on 6060 aluminium but cheap enough that I don’t care to much when they break. I’ve tested many end mills last weeks and I’ve selected six tools that where good enough for my ‘low budget’ tool library.
Tool 1: 1/8 inch double flute end mill
Tool 1 Roughing Parameters
- Conventional milling / Fusion 360 2D adaptive strategy
- 21.800 rpm
- 1000 mm/min
- 0.0009 inch/tooth
- 0.2 mm stepover
- 3 mm stepdown ( You can try higher, I got it up to 6 mm but I won’t recommend it due to the loud noise and deep axial chatter marks)
Tool 1 Axial Finish Parameters
- Conventional milling
- 8.700 rpm
- 400 mm/min
- 0.0009 inch/tooth
- 3 mm stepover
- 0.15 mm stepdown
Tool 1 Radial Finish Parameters
- Conventional milling
- 8.700 rpm
- 400 mm/min
- 0.0009 inch/tooth
- 0.15 mm stepover
- 1 mm stepdown
Tool 2: 4 mm triple flute end mill
Tool 2 Roughing Parameters
- Conventional milling / Fusion 360 2D adaptive strategy
- 13.100 rpm
- 1000 mm/min
- 0.0010 inch/tooth
- 0.3 mm stepover
- 6 mm stepdown
Tool 2 Axial Finish Parameters
- Conventional milling / Fusion 360 2D adaptive strategy
- 5.200 rpm
- 400 mm/min
- 0.001 inch/tooth
- 3 mm stepover
- 0.15 mm stepdown
Tool 2 Radial Finish Parameters
- Conventional milling
- 5.300 rpm
- 400 mm/min
- 0.001 inch/tooth
- 0.15 mm stepover
- 1 mm stepdown
Tool 3: 5 mm triple flute end mill
Tool 3 Roughing Parameters
- Conventional milling / Fusion 360 2D adaptive strategy
- 14.500 rpm
- 1000 mm/min
- 0.0009 inch/tooth
- 0.2 mm stepover
- 6 mm stepdown
Tool 3 Axial Finish Parameters
- Conventional milling /
- 5.800 rpm
- 400 mm/min
- 0.0009 inch/tooth
- 3.5 mm stepover
- .15 mm stepdown
Tool 3 Radial Finish Parameters
- Conventional milling
- 5.800 rpm
- 400 mm/min
- 0.0009 inch/tooth
- 0.15 mm stepover
- 1 mm stepdown
Tool 4: 4 mm double flute end mill
Tool 4 Roughing Parameters
- Conventional milling / Fusion 360 2D adaptive strategy
- 15.800 rpm
- 800 mm/min
- 0.001 inch/tooth
- 0.2 mm stepover
- 3 mm stepdown
Tool 4 Axial Finish Parameters
- Conventional milling
- 7.900 rpm
- 400 mm/min
- 0.001 inch/tooth
- 3.5 mm stepover
- 0.1 mm stepdown
Tool 4 Radial Finish Parameters
- Conventional milling
- 7.900 rpm
- 400 mm/min
- 0.002 inch/tooth
- 0.15 mm stepover
- 1 mm stepdown
Tool 5: 4 mm double flute end mill
Tool 5 Roughing Parameters
- Conventional milling / Fusion 360 2D adaptive strategy
- 15.800 rpm
- 800 mm/min
- 0.001 inch/tooth
- 0.2 mm stepover
- 3 mm stepdown
Tool 5 Axial Finish Parameters
- Conventional milling
- 7.900 rpm
- 400 mm/min
- 0.001 inch/tooth
- 3.5 mm stepover
- 0.1 mm stepdown
Tool 5 Radial Finish Parameters
- Conventional milling
- 7.900 rpm
- 400 mm/min
- 0.002 inch/tooth
- 0.15 mm stepover
- 1 mm stepdown
Tool 6: 6 mm chamfer tool
Tool 6: 1 mm chamfer
- Conventional milling
- 13.500 rpm
- 400 mm/min
- one pass
Tool 6: 2 mm chamfer
- Conventional milling
- 13.500 rpm
- 400 mm/min
- 4 passes 1 – 1,5 – 1,9 – 2 mm
Fusion 360 files
With the links below you can download the fusion 360 files from this project. Important: The spindle RPM in the files are not correct. Make sure to change them before you generate any g-code.
Fusion 360 Tool Library
Low budget tools 01: Click to download via Dropbox
