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Nov 4

Chattering mark in Bore - HMC



Hello Mike

Pl refer to photo showing 4 step reamer. We have a HMC for doing 6 injector bores in cylinder head (which is a casting component) thro 4 step reamer of diameters 8.5,17.23,21.26 and 26.076 mm respectively. There is an observation that after changing tool, we find chattering randomly in any of the 6 bores for dia. 26.076 mm for about 2 to 3 components and then gets ok on its own. Bore depth is approximately 100mm

Can you please advice for this random behavior as well as for chattering?



Not sure I can help much here. As with some of your other issues, this is more of a tooling issue than a CNC issue.

My comment is that if this is happening with a newly sharpened cutter and it eventually works its way out on its own (chatter dissipating after a few components), it is possible that the cutter is "too sharp" at the beginning. There may also be tiny (almost microscopic) burrs on the cutting edges left by the cutter sharpening grinding operation. I know it sounds odd, but one remedy would be to lightly hone the cutting edges of the new cutter with a polishing stone (very fine grain) to take away some of the sharpness - and also remove any "burrs".


Again, I'm no tooling expert - but I have seen this work.

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  • Topics here can include questions about programming, setup and operation - as well as any other machine usage topic.
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