Some of you might recall I was having trouble drilling out 18 gauge sheet metal a while ago. I’ve gotten better at it but still have a lot of trouble. I bought zero rake drill bits pacifically designed for thin sheet metal and a precision collet. That takes care of most of what I do but copper and stainless steel still elude me.
I’ve tried boring it with a under sized endmill, both 2 and 4 flute but heat builds up very fast, as in I can’t touch the part for a minute afterwards without burning myself, or my work holding fails.
Normal drills will stall the nomad and I can’t seem to find speeds and feeds that work for copper at all. It sort of work hardens on me.
I realize drilling is not a great idea on this system but I’d appreciate options.
When using an undersized endmill close to the size of your hole you might need to adjust your speeds and feeds to something suitable. Heat buildup is common when you are taking too small of a chip.
“Basically the feed rate is calculated at the centreline of the tool which when traveling straight is the same as the travel speed. When on the inside or for that matter outside of a circle the centreline of the tool is traveling a very different distance to the cutting face. If the tool is close to the bore size the situation becomes very very noticeable.”