Sharpening End Mills On The Lathe

**The Hobby Machinist NZ** · Feb 9, 2023, 01:03 PM

In this video I show how I sharpened my dull end mills on my lathe. I setup the end mill in the correct position and use a makeshift tool post grinder to grind the flutes.

**hemmjo** · Feb 10, 2023, 04:50 AM

Very nice. I know people say you are not supposed to do grinding on a lathe, but if you are careful and clean up when finished, it opens so many possibilities.

I have been wanting to get a CBN to use for sharpening on the lathe. As I understand the do not release grit that can damage the lathe. Has anyone done that? I don't know enough about CBN wheels yet to know that to purchase. They are pricey.

**DIYer** · Feb 11, 2023, 03:35 AM

Thanks The Hobby Machinist NZ! We've added your End Mill Sharpening Method to our Sharpening category,
as well as to your builder page: The Hobby Machinist NZ's Homemade Tools. Your receipt:

End Mill Sharpening Method by The Hobby Machinist NZ

tags: sharpening

**tonyfoale** · Sep 1, 2023, 02:22 AM

Originally Posted by hemmjo

Very nice. I know people say you are not supposed to do grinding on a lathe, but if you are careful and clean up when finished, it opens so many possibilities.

I have been wanting to get a CBN to use for sharpening on the lathe. As I understand the do not release grit that can damage the lathe. Has anyone done that? I don't know enough about CBN wheels yet to know that to purchase. They are pricey.

I use CBN and diamond wheels. Neither wear very much at all. I have probably sharpened hundreds of milling cutters, drill bits, engine valves and tappets etc, and the only visually obvious wear is a slight rounding of the edges.
Most people have the wrong idea about grinding debris. Most of it is the steel that you have ground away, only a tiny proportion is grinding wheel grit. If it were mostly wheel grit then the wheel would be wearing way too fast. Of course the opposite applies when dressing a standard type wheel, then it is all wheel grit.

When grinding on a lathe or milling machine I cover where applicable and directly under the wheel I put some flat magnets and cover them with a wet towel. That catches everything. Another implementation of the magnet idea is shown here DIY surface grinder if you scroll down the initial post.

Sharpening End Mills On The Lathe-dsc_0644.jpg

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Click for full size.
Magnets attached to the aluminium wheel cover with tape. When the tape is removed the deris just drops out.

**DIYer** · Sep 7, 2023, 04:53 AM

Thanks tonyfoale! We've added your Grinding Wheel Debris Cover to our Grinding category,
as well as to your builder page: tonyfoale's Homemade Tools. Your receipt:

Grinding Wheel Debris Cover by tonyfoale

tags: grinder, magnet