Carbide ballnose sharpening

[Dave_stoke]

Hi guys,
I have two of these 2mm can they be sharpened?

One I know is dull and doesn't cut, the other just turned red even with flood and air cutting ss. But still cuts it just went noisy.

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[spluppit]

Yes of course they can be sharpened. It's very unlikely to be cost effective though. You can get 2mm ball nose in various forms from somewhere like apt for a fiver or less and the quality is perfectly usable.

I'm a little surprised you managed to make a carbide end mill glow red without it breaking especially one that small. Are you using a router style machine and with a high rpm spindle? The chances are that cutter will be totally foobared.

[Dave_stoke]

Yes of course they can be sharpened. It's very unlikely to be cost effective though. You can get 2mm ball nose in various forms from somewhere like apt for a fiver or less and the quality is perfectly usable.

I'm a little surprised you managed to make a carbide end mill glow red without it breaking especially one that small. Are you using a router style machine and with a high rpm spindle? The chances are that cutter will be totally foobared.Yes it's a 3040T but used the feed and speed calculator that gave a speed of 7320rpm and 117 feed rate for stainless.

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[Dave_stoke]

When bits break I make face ills out of them. I polish the cutting edge so the finish is sharp too.

But round ball tips I would have to make a jig for https://uploads.tapatalk-cdn.com/20181110/574f39be9010ba377e8d9af3de666149.jpghttps://uploads.tapatalk-cdn.com/20181110/b64bf1efb986ec69671e5434624195c1.jpg

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[hanermo2]

Em..
117 feed in what ?
Metres per minute ?

Feed/rev ?
Furlongs/lightyear ?

What stainless and cutting with edge or center ?

7320 rpm sounds right, or slow.
Feed sounds impossible.


Yes it's a 3040T but used the feed and speed calculator that gave a speed of 7320rpm and 117 feed rate for stainless.

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[Dave_stoke]

Em..
117 feed in what ?
Metres per minute ?

Feed/rev ?
Furlongs/lightyear ?

What stainless and cutting with edge or center ?

7320 rpm sounds right, or slow.
Feed sounds impossible.Lol mm/min

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[Dave_stoke]

Em..
117 feed in what ?
Metres per minute ?

Feed/rev ?
Furlongs/lightyear ?

What stainless and cutting with edge or center ?

7320 rpm sounds right, or slow.
Feed sounds impossible.Going off this 25050

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[spluppit]

It's obvious is mm Min. How can it be 117 meters a min? The fastest rapids out there are in the region of 60 mtrs a min. Even if it was inches it would be nearly 3 mtrs a min, Its obvious its not that speed for a 2 mm ball mill in stainless


For a start you have to remember speed and feeds calculators are a guide, often a very general guide you have to throw away. These speeds and feed will be optimum for optimum cutting conditions on a proper machine.

The problem he has is the machine. It's a very weak machine not deigned for cutting metals. You will be getting tons of deflection, if you deflect you do not cut, if you deflect you rub, if you rub you generate tons of heat compounded the fact you are working in stainless. A bad combination that will always be problematic.

Carbide needs to be worked and made to cut. If you don't have a machine with the rigidity to do this you will always be fighting a battle.

[Dave_stoke]

It's obvious is mm Min. How can it be 117 meters a min? The fastest rapids out there are in the region of 60 mtrs a min. Even if it was inches it would be nearly 3 mtrs a min, Its obvious its not that speed for a 2 mm ball mill in stainless


For a start you have to remember speed and feeds calculators are a guide, often a very general guide you have to throw away. These speeds and feed will be optimum for optimum cutting conditions on a proper machine.

The problem he has is the machine. It's a very weak machine not deigned for cutting metals. You will be getting tons of deflection, if you deflect you do not cut, if you deflect you rub, if you rub you generate tons of heat compounded the fact you are working in stainless. A bad combination that will always be problematic.

Carbide needs to be worked and made to cut. If you don't have a machine with the rigidity to do this you will always be fighting a battle.Yes I was pushing it to be fair. I can see the head twist on a downward cut. It's fine on brass and ally, with brass being brittle and ally being soft and gummy.

But now I get why it was twisting.

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