Quote Originally Posted by Muzzer View Post
In my experience, chip welding (recutting) is the risk with deep slots in loominum. Pretty much all of the cutters I've broken over the last 2 years have been due to this. The best solution in my situation seems to be to ensure a constant supply of flood coolant, which both cools the chips down and clears the from the danger zone. I don't know if that would work for you, depends how much coolant you get get in there. Must admit, I do get a bit carried away with the feeds and speeds which probably doesn't help.

Using a smaller cutter and an adaptive path might at least reduce the chip size a bit and leave more room for chips and coolant to evacuate. If you are doing a 25mm deep slot with a 4-5mm cutter, you will be doing it in several (4-5?) stepdowns.

Dunno what others think?
To be honest, I haven't had any chip welding while using flood coolant. Even if the cutter is running through a pile of chips it sounds grainy and generally to be avoided but it hasn't actually damaged the bit so far. The flood coolant is not as good at removing the chips in a deep slot though, when compared to an air pressure feed. Unless the coolant is pumped into the slot at high pressure, which makes a massive mess of the enclosure, the chips kind of sink in a pool at the bottom of the pocket / slot.
As for the step downs, I'm pretty new to this and am being very conservative on cutting depth. I won't go more than 1mm cut depth for a slot. As I'm not cutting for cash, I don't mind high cycle times and although my machine is capable of cutting deep pockets in Al, I don't want to risk any more carbide cutters.