I’ve heard about negative rake...

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Ray-CA

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Nov 14, 2020
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..tools and understand why they’re used but have a question. Could I flip a standard rake (positive rake?) cutter upside down and do the same thing?

Just asking...

Ray
 
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monophoto

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Basically, yes, but - - -

The thing about scrapers is that it is the burr that does most of the cutting. The burr on a standard scraper points upward, so if you flip the scraper upside down, the burr will point in the wrong direction.

So what you would have to do is modify the way you sharpen your scraper so that the burr is on the opposite side.

But having said that, if you are going to modify how you sharpen your scraper to put the burr on the opposite side, it would be a relatively simple step to also regrind the scraper to the negative rake configuration. All that is required is that you grind a slight bevel on the top side of the scraper. Obviously, the thicker the tool, the more easily it can be converted from conventional to negative rake because grinding a bevel on the top reduces the size of the bevel that can remain on the bottom.

There is nothing sacred about the grind on a scraper when it leave the factory, and professional turners frequently modify the grind to meet the requirements of the job at hand.
 

RunnerVince

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There is nothing sacred about the grind on a scraper when it leave the factory, and professional turners frequently modify the grind to meet the requirements of the job at hand.
This was one of the most empowering lessons to learn with woodturning. When I first started, I was so concerned with keeping everything the same as it came. Now, if I don't like a tool, I just modify it. I have a set of cheap tools I got with my first lathe, and I keep regrinding them whenever I need a "new" tool--especially for "one-time" uses.

There's a blacksmith on YouTube named Alec Steele, and one of the things he used to say quite frequently is "need a tool, make a tool." Words to live by.
 

monophoto

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have a set of cheap tools I got with my first lathe, and I keep regrinding them whenever I need a "new" tool--especially for "one-time" uses.
I made some special purpose scrapers by regrinding Harbor Freight bench chisels, The only cheaper approach would be to regrind old chisels bought at garage sales.
 

howsitwork

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Jul 9, 2016
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Nothing wrong with grinding the shape to suit what you need, either scraper or cutting edge tool.

I have made a number of round skews from HSS bar and they are
a delight to use.

Likewise David Springett in his “woodturning wizardry “ book explains a number of tools to make some of the projects . If you ever come across a copy it’s a brilliant and inspirational read.
 
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