I’m still generally new to CNC machines, so forgive any naivety. I’m currently trying to mill a very small model but I’m running into an issue. For context, I’m using Fusion360 to generate my G-code and I’m using the recommended speeds and feeds for my tool (Datron, 3mm single flute, #0068630E) to operate on aluminum stock. I first tried to mill on the plastic delrin cube stock just to get a feel of the model itself, and had no problems whatsoever.
However, when I switched to the aluminum cube stock, everything goes fine until maybe an hour later when I notice that the noise from the milling operation starts sounding different. Then, in a few minutes after the noise change event, the tool breaks at the shaft. I am using the exact same tool and the exact same recommended settings for aluminum stock that I used before, so I don’t know what’s going on. The cutting flutes still seem sharp on the tool part that broke off. One thing of note is that I am using a 2D Adaptive milling operation for my toolpath, so I know the tool is “optimally” engaged with the stock material the whole time. I don’t know if this is the reason, but any clarification would be greatly appreciated! I am just confused because I’ve milled aluminum stock in much greater volumes and durations before with no issues using the facing operations, but now it seems that I cannot mill my 2D adaptive operation for any longer than an hour or so before tool failure. Is it because I am milling in a constant adaptive toolpath for too long? Is it dullness? Overheating? Again, thank you for any help!