End mill centre clearance

[John RuddParticipant @johnrudd16576]

So while I await the arrival of my Worden kit (due tomorrow…👍 ) I'll ask another question…..

What do folk use for adding the clearance on end mills that are not centre cutting…or even those that are…

I see some of my cutters are gashed and others have a ground depression….

The ground depression isnt easy to achieve from what I've tried ( carbide burr, tapered grinding point…) I guess gashing with a thin blade of some sort is the order of the day…?

So how do you achieve your clearances?

Edited By John Rudd on 14/10/2020 10:30:48

[John RuddParticipant @johnrudd16576]

[John HaineParticipant @johnhaine32865]

Unless your cutter is badly worn/resharpened it shouldn't need more off, but if it does then gashing is the only thing you can easily do, using a thin cutting disc. IIRC Chaddock describes it in the Quorn book.

[Tony Pratt 1Participant @tonypratt1]

Thin saucer shaped wheels.

Tony

[Thor 🇳🇴Participant @thor]

Hi John,

On the centre cutting endmills I use a thin cutting disc in my Dremel before grinding the cutting edge.

Thor

[John RuddParticipant @johnrudd16576]

Thanks for the replies everyone,

So are we gashing the clearance free hand or using some jig/toolholder while doing this?

I'm thinking that anything sized under say 8mm is going to be a challenge?

[Thor 🇳🇴Participant @thor]

I'm doing the gashing free hand, and yes, my old eyes struggles with the small cutters so a jig is on my to do list.

Thor

[Chris Evans 6Participant @chrisevans6]

I mount up a thin elastic cut off wheel and gash freehand. I do a batch then set up the Cuttermaster cutter grinder for side or end work as required.

[Clive Brown 1Participant @clivebrown1]

I don't recall the Prof. describing gashing in the original ME series, but he did emphasise the delicacy of setting up to sharpen slot drills which had an over-centre cutting lip. In those days, all end mills seemed to come with central hollow, whereas now they all seem to be centre cutting.

Another point he made re end mills was to sharpen with the end teeth set in 1 deg. inwards towards the centre.

This is to allow for tooth wear being greatest on the outer diameter and avoid cutting on the heel of the tooth.

[Howard LewisParticipant @howardlewis46836]

Afraid that I gashed the few that have been sharpened with a thin disc in an angle grinder. Not very precise, but did what was required at the time!

Howard

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