Saturday, March 20, 2010

learn from my mistakes

I am absent-minded. Always have been, since I was a child. Some of it seems to be connected to the ADHD, and some of it is sleep- and hydration-dependent. I get a lot worse when I'm sleep-deprived or dehydrated. But I digress. Again.

A few weeks back, I needed to machine a part. The stock was centerless-ground hardened shafting, made of some high grade steel and probably as hard as a Nickolsen file. I cut off the bit I needed with an abrasive cut-off wheel mounted in my angle grinder.

I intended to detemper it with Ze Torch before machining it, since I don't have carbide cutters, nor cooling, nor all day.

Then I set it and the part it would go into aside for the night, as I was getting tired.

In the morning, I secured the part in the mill and attempted to machine it.

Carbide could have done it, although I'm sure I was running the wrong speed-n-feed for a carbide tool even if I owned one.

But my cobalt steel end mill wasn't having any of that nonsense, and now I need a new cutter:

dull end mill.jpg

Perhaps I'll buy a carbide end mill to replace it, unless I get sticker shock.


Bill Lemieux said...

$32 for sub-micron premium micrograin carbide (TiNC coated) vs. $12 for bare cobalt. Ouch. Tough call...

Bill Lemieux said...

It turned out I had a replacement for this size in among the end mills an old friend sent me some months ago. And of course, I can still use the SIDE of that cutter...