Endmill failure or wrong feeds and speeds?

[CNCOlly]

Some sound advice there Lee thanks for taking the time to make this response. Prior to starting the cut shown in the video I made a similar piece with all the same settings, F&S, DOC etc and wood from the same batch. The first run appeared to go absolutely fine with a good finish. So I did a new design and decided to record the cutting. The instant the cutter started it sounded wrong and I almost hit the reset button but for some reason left it going. The endmill appeared to resonate at a different tone.

So for the following, I used the guide on the Renne tools website https://www.rennietool.co.uk/blogs/n...eeds-and-feeds.

What made me approximate the depth of the cut was using the rule of thumb of half the cutter diameter. Which doesn't make sense to me the bigger a cutter gets. Then to come up with the feed rate I calculated what the minimum feed rate is based on their table playing it safe with the lowest values.

1/2 inch endmill in Hardwood = Chip Load 0.483 * 18000 RPM * 2 gives a feed rate of 17388mm/min 6mm DOC.

So the thinking was that a 4000mm / min would be no problem for even a poor-quality bit. I'll get a better quality solid carbide bit on order, as you say it's a waste of time with the cheap bits like I used. I'm just a bit nervous about coming up with the starting feeds, speeds and DOC. I'm wondering how you would approach F&S and DOC for a 1/2 " bit. Have I gone about it the right way but just used the wrong endmill?

I since finished off the project I was making using a 6mm solid carbide endmill and managed to recover the bit of wood thankfully.