# Help grinding end mills



## churchjw (May 21, 2012)

OK so I just started grinding my own end mill on my surface grinder using a simple fixture.  Two and four flute end mill are going great and then I hit a wall.  What is the trick to six flute cutters? 





Here is my botched first attempt.  This cutter is rough to start with so no great loss but I would like to do this with nicer cutters at some point.  If I set it the same way as I do for a 4 flute the wheel will hit the other teeth.  Or it looks like it would.  I cut the center out with my bench grinder.  There has to be a better way.  Any help with set up or general end mill grinding tips would be greatly appreciated.  

Jeff


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## 4GSR (May 21, 2012)

Get you a six flute end mill with a good end to look at.:thinking:  I bet you already thought of that....


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## Hawkeye (May 21, 2012)

The thing that lets a 'real' tool grinder do the 6-flute cutters is a cup wheel that can get in close without hitting the next tip. In that case, the tool is oriented horizontally to approach the rim of the cup wheel. A surface grinder is presenting the bottom edge of the traditional wheel to the cutter facing upward. The edge of the cup wheel is less than 90[SUP]o[/SUP] to the 'front' plane.


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## Rockytime (May 21, 2012)

I don't sharpen my end mills. They stay sharp quite a while as I cut very little steel and then usually 12L14. I will buy new drill bits. That is not cost effective. Since I do not have the equipment, time or patience I would like to find someone who does this professionally. I just wonder about the cost. does anyone on the list send out their end mills?


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## churchjw (May 22, 2012)

Thanks guys.  Not the answer I was hoping for but very helpful.  Yes, that is the fixture I am using and it says it can be used on 6, 8, and 12 flute bits but its apparently wrong :biggrin:.  Oh well still worth it to sharpen the 2 and 4 flute ones. I have a buddy with a cup sharpener so I will by him a new wheel so I can learn that process.  As far as cost.  This was mostly to learn how to do it because it was interesting and fun.  Not sure it would be cost effective in a production shop but for the hobbyist it works.  Also chipped and dull HSS cutter are cheap or often free so for a little time I get free cutters.  A buddy gave me the ones I was playing with (about 20 or so from .500 to 2.000") The 2 and 4 flutes will be usable and maybe the 6 flutes at some point.  But mainly it was fun.:biggrin:

Jeff


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## churchjw (May 22, 2012)

Bill Gruby said:


> Yes it will grind 6-8-12 flute endmills but you need to go to smaller width wheels to gri9nd them. That is why I said better for 2 and 4 flute endmills. It takes a lot of practice to grind multiple lipped tooling. You will get itI am sure. Keep at it Bro.
> 
> "Billy G" :thumbzup:



I just got a .250" thick  wheel should I try with it instead of the .500"?

Jeff


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