Holes with interrupted cuts / offset holes, how to cut?

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Bentworker
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Re: Holes with interrupted cuts / offset holes, how to cut?

Post by Bentworker » Mon Jan 14, 2019 6:47 pm

I like the annular cutter idea, if I come across any for a good price I'll have to get some.
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BadDog
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Re: Holes with interrupted cuts / offset holes, how to cut?

Post by BadDog » Mon Jan 14, 2019 8:27 pm

Those get quite expensive for typical home shop use. But they are wonderful when combined with a mag drill for structural steel work (trailer/truck/car frames, etc). For use on fixed machinery like a mill, unless you do a lot, or have a very specific need, end mills (and/or boring heads) are far more economical and flexible.
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rudd
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Re: Holes with interrupted cuts / offset holes, how to cut?

Post by rudd » Mon Jan 14, 2019 9:08 pm

OK, I get the torque transfer in straight line accel/decel situations, I'd think the hub would be under a good bit of stress on hard cornering. I don't believe I'd take that job in my shop.

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Bentworker
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Re: Holes with interrupted cuts / offset holes, how to cut?

Post by Bentworker » Mon Jan 14, 2019 9:46 pm

Yeah, those annular cutters are not cheap, especially the 2” depth of cut ones! I had access to several 1” depth of cut ones, but not anymore since I switched up employers.
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GlennW
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Re: Holes with interrupted cuts / offset holes, how to cut?

Post by GlennW » Mon Jan 14, 2019 10:03 pm

Don't neglect to consider the sharp corner that an annular cutter would leave at the base of the bore if used in the context of this thread.

A boring bar can be ground to leave a suitable radius to help eliminate stress risers.
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johnfreese
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Re: Holes with interrupted cuts / offset holes, how to cut?

Post by johnfreese » Tue Jan 15, 2019 8:11 am

I would drill the holes undersize and follow with an end mill to guarantee the finished hole did not drift. For the counterbore I probably don't have the correct size endmill so I would check my stock of counterbores. If none of them were the right size I would use a boring head.

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