# Negative Rake Turning Tools - Question...



## SteveG

I see a variety of negative rake turning tools and carbide inserts being suggested and sold for certain turning applications, such as some of the more brittle plastics. I do not have any of these tools, but do have a question. Perhaps those with experience with these tools can address my burning curiosity. Could the turner achieve the same effect by using a standard scraper tool, and simply raise the handle a bit to achieve the same negative rake angle. It seems so simple, so I question the value of buying dedicated negative rake tools and/or inserts.


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## randyrls

Steve;  I just use a standard carbide, but present the tool below center.  The further below center the more aggressive the tool, but the greater the stress on the blank.  Take a look at these two carbide tools. The lower bit will cut endless ribbons from the hardest, chippiest, acrylic if presented below center line.


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## WriteON

I have a negative rake  chisel. It’s dull and have no idea how to properly sharpen it. Have used it since Feb and have yet to realize the benefit.


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## Ted iin Michigan

I'm thinking the answer to your question is "no". Not completely sure why but the included angle has something to do with it. I had a standard one that I reground and am getting superior results with it now. I tried a lot of different stuff with it before and had only limited success. Best results were to keep it perfectly parallel to the floor but any deviation resulted in a catch. No issues with that now. Resharpening often and keeping a nice burr on the top edge is important.


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## jttheclockman

I have yet to meet a material I can not turn with either a standard carbide cutter or HSS cutters. I think those just need practice if you can.


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## WriteON

jttheclockman said:


> I have yet to meet a material I can not turn with either a standard carbide cutter or HSS cutters.


Aside from sharp tools being everything its the archer not the arrow


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## philipff

SteveG said:


> I see a variety of negative rake turning tools and carbide inserts being suggested and sold for certain turning applications, such as some of the more brittle plastics. I do not have any of these tools, but do have a question. Perhaps those with experience with these tools can address my burning curiosity. Could the turner achieve the same effect by using a standard scraper tool, and simply raise the handle a bit to achieve the same negative rake angle. It seems so simple, so I question the value of buying dedicated negative rake tools and/or inserts.


Yesterday I turned 4 acrylics with standard tools; ruff gouge and skew, then sand paper to 600, then the 10 steps of fine until 1200 was reached, followed by plastic polish.  Brilliant results.  Carbide is not required for anything.  P.


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## monophoto

Steve 

Call me cynical, but - - -

Tool manufactures know that wood turners (or for that matter, anyone engaged in any kind of craft activity that uses tools) tend to be tool junkies who find it very hard to resist shiney new gadgets.    I'm just as bad about that as any other turner.  Very few new tools can do anything different from what conventional/traditional tools have been used for.  Instead, those amazing new tools that appear in pretty pictures in advertisements are, at best, slight improvement that might be a bit more convenient or save a little time, or at worst, gambits to get you to buy a shiny new tool so that the manufacturer/seller can make money.

When I first started turning, I understood that the right way to use a scraping tool is to have it approach the piece slightly below center, and with the tool handle raised slightly above center.  That is, the scraping is the process of dragging an edge against the turning piece.  And the material from which the tool is made is irrelevant - carbide tools are also scrapers.  By contrast, cutting tools like gouges and chisels, are best used by approaching the turning piece above center with the handle held in a lower position - so that the edge of the tool slices into the turning material.

And remember that there was a time when all turning tools were scrapers - gouges and chisels as we know them today are  relatively new developments.

Along came 'negative rake' tools.  The only real difference is that they are designed to have the front edge of the tool slightly lower than the trailing edge, so that if the tool is held in a perfectly horizontal position relative to the turning material, the cutting edge is pointed slightly downward so that it can scrape - it is being dragged against the surface of the spinning piece.  I've seen the argument that 'negative rake' tools are better because the included angle is 'better'- I'm sorry - that's BS.    You can have any angle you want on HSS tools - it's all in how you choose to sharpen the tool.


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## jttheclockman

Just like with turning tools in general, you can get the same results with basically one tool except that some tools make the job easier and at times safer. I mentioned the use of carbide tools and cutters. I believe that was a step in the right direction of being a tool that is beneficial. Can we get away with not using them??  Sure we can but with certain materials such as turning metals and that is where I use them they save so many trips to the grinder or the honing stones. The use of carbide on blades such as tablesaw and bandsaw and planer blades was a huge stride in the industry. But getting cute with different angles such as negative rake tools is just as someone mentioned someone trying to build a better mousetrap that is not needed to be built in this area. But as also mentioned people who work with tools become tool junkies and love new innovations and I have been a victim over the many years I have been working with all kinds of tools and probably will continue even though I am getting up in the age dept. It was the main reason I stopped all woodworking magazines and all magazines in general    because they are full of ads that are eye candy to junkies like me. The meat and potatoes can be summed up in a couple pages and they would not sell well. If people would just learn the proper use of the tools they do have and stick to basics they can accomplish much more than they think and not need all those specialty tools. But if you have the cash and need to feed the fix have at it. That is the customer base they target.


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## bmachin

Stuart Batty wrote an interesting article in the Spring 2006 issue of American Woodturner on negative rake scrapers, where they perform very well in everyday turning and where they are the only tool that will get the job done.  If you are a member of AAW the article is worth a look.

As far as sharpening is concerned (Full disclosure: I don't own one yet, but have done a lot of reading and say them used at the AAW symposium in Raleigh): 
1. You have to maintain a burr which means resharpening very frequently.
2. If you have a chisel style tool (i.e. it looks like a skew chisel) sharpen both sides just like you were sharpening a skew and use it with the side you ground first up.
3. If you have the more traditional scraper type tool just grind the bottom bevel, although you may need to hone off the what remains of the old burr. Must be videos on this out there.
4. Type of steel in the tool makes a big difference. Stuart says the burr on M2 will last 10-15 seconds while V10 (A11) will last several times longer).

Here is a Stuart Batty video comparing the use of a standard scraper to a negative rake scraper in the bottom of a  honey locust box:






Hoping to shed some light,

Bill


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## SteveG

Thank you to all who responded (or will respond). Opinions seem to be all over the place, and I find that valuable. I do not intend to acquire any neg-rake tools any time soon, as I have had fine success using what I already have. Thanks for the Batty video bmachin. That was informative, and offered a look at the differences between how the standard and negative rake tools are employed, and some of the functional differences. I am enjoying the discussion.


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## leehljp

What is the difference between using a scraper that is angled downward about 5° from the tool rest (handle end up) VS a 5° negative rake insert? There than the difference between one being carbide and the other being HSS, both will be attacking the wood . . or cutting the wood with the blade at a negative angle in comparison to level.

That said, I use the negative attack angle with my HSS scraper on occasion in smoothing the blank so that sanding is not needed.


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## bmachin

Hank,
I don’t know what the rake angle on a carbide NRS is, but most hss versions are ground with a top rake of 20-30 degrees and bottom rakes of anywhere from 50 to 70 degrees. Here is along thread from the AAW Forum discussing this. 






						Negative rake scrapers?
					

I am having difficulty figuring out the advantage of negative rake scrapers in the general sense. I've read Cindy D's paean to them, and those of others, and it seems the actual "cutting edge" (angle of the bevel to the top surface) is the same as that of a standard scraper. The angle of attack...




					www.aawforum.org
				




Bill


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## leehljp

bmachin said:


> Hank,
> I don’t know what the rake angle on a carbide NRS is, but most hss versions are ground with a top rake of 20-30 degrees and bottom rakes of anywhere from 50 to 70 degrees. Here is along thread from the AAW Forum discussing this.
> 
> 
> 
> 
> 
> 
> Negative rake scrapers?
> 
> 
> I am having difficulty figuring out the advantage of negative rake scrapers in the general sense. I've read Cindy D's paean to them, and those of others, and it seems the actual "cutting edge" (angle of the bevel to the top surface) is the same as that of a standard scraper. The angle of attack...
> 
> 
> 
> 
> www.aawforum.org
> 
> 
> 
> 
> 
> Bill


Thanks Bill. I actually make (grind) my own scrapers to an angle (viewed from the top) so that I do not have to hold the scraper 90° to the turning blank. I have two that are angled away from 90°. Viewed from the top: 1.  /__/    & 2.  \__\ instead of |__| (90° squared end). That is viewed from the top. Then viewed from the side mine are somewhat like this:  ─/ . 

From what I read in that link, I probably need to make the side view somewhat like this: > . . .only more angled downward to a 70° or so.

That link helps and I will experiment with the angles. I appreciate this very much!


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## crokett

the negative rake carbide cutters don't do anything that you can't do with a standard cutter.  I hold my standard carbide cutter slightly below the centerline when turning acrylic (I call anything that is cast acrylic.  I know there are various forms of acrylic and polyresin.) .   Wood and aluminum or brass I use HSS tools.


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## howsitwork

I can only say I have had success with plastics using a 1/2”  round bar skew chisel I ground up  myself. Best honed for a fine edge and VERY  gently presented square on ( the edge that is ) to the blank. I have aprecently git a neg rake scraper but haven’t as yet used it enough to comment on its use ( or my ineptitude / ability to get a decent finish with it ).
I too have chased the new tool wagon for many years but alway seem to come back to my HSS  30mm Henry Taylor roughing gouge , an Ashley Isles1”  curved skew chisel ( Reground to curved as I found it worked better for me ) and two smaller angled edge skew chisels used as skews or scrapers . The latter two made from Isles round bar blanks bought for the purpose.  

When i first tried plastics aside from the streamers from the edge causing a problem wrapping around  the work , provided I kept everything sharp , preferably honed , it worked.   

Whatever works for you as long as it’s safe , and preferably enjoyable to do ....


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## leehljp

howsitwork said:


> I can only say I have had success with plastics using a 1/2”  round bar skew chisel I ground up  myself. Best honed for a fine edge and VERY  gently presented square on ( the edge that is ) to the blank.
> 
> Whatever works for you as long as it’s safe , and preferably enjoyable to do ....



Agreed. I have my own scraper that is radiused like a radius square carbide insert, but presented at an angle, not 90° to the blank. Very Comfortable! I use other tools and come back to it. When one gets proficient with two or three or four tools, the experience from those lead one to "figure out" how to adjust to a new one, especially one designed from one's own wants and needs. 

I enjoy the creativity that is shown on this forum, not only with pens but with the tools.


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## howsitwork

Hank

you're speaking my language there. 

Hope you had  a good new year’s eve and the mornings as glorious there as it is here ! Sunshine, minimal cloud and birdsong accompaniment.


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## More4dan

Or you could just mount a regular cutter with a negative rake and get the same effect. It would allow you to hold the tool flat as you turn which is easier to hold consistently.




 The blank in the picture is a piece of inlace acrylester as turned with no sanding.  It does allow the use of lower cost inserts and can be resharpened. 
Danny


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## howsitwork

Nice Danny.  

might give it a go as I have lots of carbide inserts from metal turning which I could try out. Sometimes the journey is as much fun as the arrival.


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## More4dan

howsitwork said:


> Nice Danny.
> 
> might give it a go as I have lots of carbide inserts from metal turning which I could try out. Sometimes the journey is as much fun as the arrival.



I’ve found that the inserts for cutting metal have too blunt of an edge for wood and resins with the exception of those made specifically for aluminum. 


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## howsitwork

Yes the aluminium ones have a far higher rake angle ( sharper edge ) and so work better for wood. 

Thanks again

Ian


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## More4dan

howsitwork said:


> Yes the aluminium ones have a far higher rake angle ( sharper edge ) and so work better for wood.
> 
> Thanks again
> 
> Ian



Let us know what you come up with, I love to see the results. 

Danny


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## howsitwork

i don’t think my efforts will be as elegant as your solutions but .ive got a week off to play so ...

Will send photos of attempts.


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## David350

Danny, what angle did you mill into your bar stock?  Was it 30 degrees?  Thanks, David


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## More4dan

I used 20 degrees, more or less matching the negative rake angle of the carbide cutters being sold. 

Danny


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## David350

Thanks Danny!


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## peter1958

WriteON said:


> I have a negative rake  chisel. It’s dull and have no idea how to properly sharpen it. Have used it since Feb and have yet to realize the benefit.


Mr Piece has a nice video on the negative rake scrapers: (12) Negative Rake Scraper Basics - YouTube


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## SteveG

I just viewed this thread, then was surprised to discover that I was the OP back in July. Nice discussion and great info!


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## mmayo

jttheclockman said:


> I have yet to meet a material I can not turn with either a standard carbide cutter or HSS cutters. I think those just need practice if you can.


I have some experience with the three cutters you mention. To me the negative rake carbide is far easier to use with tough chippy plastic or any plastic. It is more forgiving. While I usually don’t use it, I do sometimes and I’m always pleased with the way it cuts.


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