I got some 10mm carbide slotdrills (very cheap) which are a bit dinted and none-too-sharp, and wondered whether it might be possible to sharpen them by running them backwards in a lathe and applying a flat diamond "stone".
The rake would be almost-unchanged after sharpening, but there would be no relief/clearance over the cutting edge - though that would only be for about
1 mm, then there would be lots of clearance.
sort of like this:
. \ . \ tool cutting ->
.----____\ _____ .----------| | . | workpiece . |
Would this work? Any reason why it's a bad idea? I have no idea how they are sharpened properly - how much does it cost, and is it worthwhile? And no, I'm not going to build a Quorn just yet, I'm only a beginner :)