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Rough day with a Citizen M20 near Akron - tool offset or program error?
I was running a batch of 304 stainless bushings on a Citizen M20 lathe last Tuesday near Akron. The tool offset looked fine on the first ten parts but then the finish pass on the ID went wild and I ended up scrapping fifteen pieces. Now I'm torn between thinking it was a worn insert or maybe a glitch in the program from a tool change cycle. Does anyone else deal with these sudden quality drops on Swiss machines or am I missing something obvious here?
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vera_palmer1mo ago
Woah, wait. FIFTEEN pieces? That's brutal. I'd be pulling my hair out over that kind of scrap. Never had a run that bad on my M20, but I've had a few close calls with worn inserts on 304. Actually had one where the insert chipped mid-cycle and the ID finish went from mirror to garbage in two parts.
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bennett.mason1mo ago
Dude, "mirror to garbage in two parts" - I felt that one. @vera_palmer you hit the nail on the head. I had something similar happen on a run of 316L flanges last spring. Thought I had everything dialed in, inserts were fresh, coolant was on point. Then half way through the batch, the finish started going fuzzy on me. By the time I caught it, I had four parts that were basically scrap. It's like the material just decided to fight you for no reason. Makes you wonder if the bar stock had some weird grain structure or something. Your M20 must be a tank to only have close calls, my little lathe would have probably thrown a fit.
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ryan36927d ago
Man that's rough. I've had the same thing happen with 316L, it's like the stuff has a mind of its own sometimes. You think you've got the feed and speed perfect and then bam, it goes to crap halfway through the batch. I've had a few runs where I ended up chasing parameters for half the job before it settled down.
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