Posted by BillS on May 03, 2014 at 17:24:36:
In Reply to: Re: fellows 20-4 stroke n feed formula posted by abnormal shaper cutter wear? on May 03, 2014 at 09:10:40:
I'm not familiar with fellows 20-4, but perhaps you could give some detail:
(1)is this the first gear that you have setup on the machine?
(2)Has it been successfully set up and cut other gears?
(3)Is the fixture/gear rigid? Gear blank cannot be allowed to rotate in fixture, even slightly. Sometimes, when cutter is dull or improperly sharpened, chip formation can cause excessive tangential forces.
(4)Does stroke extend well below and above blank?
(5)Does machine allow switching between up and down cutting? Is it forming a chip?
(6)Are tooth flanks rough, or is tooth profile distorted?
(7)Does machine make unusual sounds, hammering, or loud sounds of any kind. It should be fairly quiet.
(8)Is it cutting under oil bath?
(9)Is the chip thickness proper? Should not be taking a thin chip - usually hard materials are best machined with reasonably thick chip. A really small feed rate can cause a cutter to dull quickly, and that may be part of the problem. Someone else will have to give you a feed rate for that material based on their experience.
I thought I would ask these questions, since others will want to know more about your setup, results, etc.
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