Milling problems with aluminum


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!


The feeds and speeds strategies change depending on which Pocket NC you were using. Let us know if you were using the Pocket NC V2-10 or V2-50. Also provide your spindle speed, feed per tooth, depth of cut, and side load (optimal load in some instances). If you like, you can share your Fusion 360 file and we can look at your settings. Send your information to and provide your machine’s serial number, click here to determine your machine’s serial number. Thank you.

Thank you for the help! I emailed that address you provided with all the information requested. One additional thing of note: I’m running into these problems when I’m performing my “[T3] Outline” toolpath (the very first one). I have not attempted any of the other planned toolpaths.