ramaroodle
Member
How do you sharpen a negative rake carbide tool?
I don't have any carbide much less a negative rake, however if I was going to sharpen the round ones here is what I would do. I would get a rod and drill and tap a hole in the end to match the screw for the insert. Then with the insert screwed to the end of the rod spin it in the lathe, drill press or even a hand drill. Touch a diamond hone on the right angle to it and it would hopefully sharpen it.
One of the big selling points of using carbide is to have a tool that doesn't need to be sharpened. Doesn't sharpening the insert kind of defeat the reason for them in the first place?
But wouldn't the same effect be created by tapering the top of the bar on which a flat-top cutter is mounted? And because it has a flat top, it can be sharpened with a diamond hone.
Now THATS what I'm talkin bout! A man after my own heart. What a great idea! Certainly worth a try.As monophoto stated above, the same effect can be created by tapering the top of the bar on which the cutter is mounted. This is a tool that I made which mounts the cutter at 20-degrees so the scraper is presented with a negative rake angle. So far it is working very well.
Regards, Dave (egnald)
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I've had the same inserts for two years plus the ones I bought thinking the other ones couldn't be sharpened. I have a slow speed grinder and gouges that I haven't touched in 2 years. Maybe someday I'll turn a bowl or two. I use a round and 2"radius carbide tool and a 3/4" Benjamins Best skew and sharpen them all with a card-sized hone. I'll put the skew on my Work Sharp once or twice a year. I've made over 100 pens and they are always sharp as can be after a minute or 2 on the hone. PLUS you rotate the inserts 90 degrees so it's like having 4 sharp blades so I get 20-30 pens between sharpenings. But I digress.Where I was going with that is many people get carbide tools so they don't have to get a grinder (cost or space) and learn to use it. They just have to turn the insert when it gets dull until there are no sharp edges the put in a new one. Somewhere in the process they realize the cost of inserts adds up and the search for ways to sharpen them comes to the conversation.
Where I was going with that is many people get carbide tools so they don't have to get a grinder (cost or space) and learn to use it. They just have to turn the insert when it gets dull until there are no sharp edges the put in a new one. Somewhere in the process they realize the cost of inserts adds up and the search for ways to sharpen them comes to the conversation.