interesting negative rake tools *LINK*

Re: interesting negative rake tools

Don Orr

Very interesting! I like the size of the system-lots of mass. Wonder if they will be available in the USA ? If I had metal working machines they would not be difficult to make.

Thanks John.

Re: interesting negative rake tools

Reed Gray

It might be my hearing, and his accent, but I didn't catch what type of metal he uses for the cutters. Not sure if the upside down orientation of his compared to the more standard variations would make any difference or not. Looks like a nice cam lock for his handles..

robo hippy

Re: interesting negative rake tools

john lucas

I rewound it and listened to it 3 times and still didn't get the steel type. May have to write him and inquire. My thoughts would be to buy a Thompson Scraper and cut it into short lengths that could be ground and cut to shape.

M42 steel *LINK*

john lucas

Here is his website with more info.


https://hopewoodturning.co.uk/tools-handles/negative-rake-scrapers/

upside down bevels

John K Jordan

>>>Not sure if the upside down orientation of his compared to the more standard variations would make any difference or not.

I tried some "upside down". I think the biggest difference in the upside down grind would be the cutting edge would be closer to the tool rest. It should work the same.

Re: interesting negative rake tools

GaryG in MD

Nice tool.

I'm a fan of NRS and don't use mine as often as I should. Need to be more aware of that.

The one thing he glossed over is the sharpening of the round one on an electric drill (if I heard correctly). He didn't show that, and it might give me some concern for how that is done in a simple and well-controlled manner.

Re: interesting negative rake tools

William Duffield

What he said was "HSS, cryo cooled."

Re: interesting negative rake tools *LINK*

Mike Stafford

Very interesting tools. The squarish tool does not appear to have hundreds of sharpenings in it before the bevel will end up partially under the tool shaft where it fastens. Nevertheless I do like the concept of a replaceable tip and I know the mass of the tool is beneficial.

Recently I had the opportunity to try out these negative rake scrapers being sold by Boxmaster Tools which is now a part of D-Way Tools. They are wonderful. I am constantly finding new uses for these tools and the long and strong version has similar mass to the tool in the video to which John linked.

Boxmaster Tools

Re: interesting negative rake tools

George Balock

I’m like John K. Jordan in that all of my scrapers, with the exception of hollowing tools, are ground with a negative rake. Is there a big advantage to using M42 over HSS in this application? I would think that you would get a larger, but softer burr on HSS. His tools do seem to cut well on the wood he is demoing on. And I’d want a round shank on the round tool for shear scraping side grain.

Re: interesting negative rake tools

John K Jordan

>>>...Is there a big advantage to using M42 over HSS in this application? ...

What type of HSS, M2? I thought M42 is HSS. (with the addition of cobalt)

JKJ

Re: interesting negative rake tools

George Balock

John K Jordan, to be honest, I don’t know what type of steel they are, but probably M2.

Re: interesting negative rake tools

Ralph Lindberg

Background... I am friends with both Dave (founder of D-way) and Jimmie (founder of Boxmaster)

When Jimmie was developing Boxmaster NRS he worked closely with Dave for the process and metal. So he certainly could have gone with M42, but they decided for this application that M2 worked better.

Now Boxmaster tools are not heat-treated the same way as most M2, they (Jimmie and Dave) developed a process based on Dave's heat-treat for M42.

The result is Boxmaster test out harder (Rockwell) and more wear resistant the other M2 tools. The heat treat plant they use also produces a more consistent heat-treat (considering who they heat-treat for... the aero-space industry) then most plan "tool" shops.

Re: interesting negative rake tools

John K Jordan

>>>Now Boxmaster tools are not heat-treated the same way as most M2, they (Jimmie and Dave) developed a process based on Dave's heat-treat for M42.

The result is Boxmaster test out harder (Rockwell) and more wear resistant the other M2 tools.

So what is the Rockwell number?

Re: interesting negative rake tools

Ralph Lindberg

64 +/- 1

Re: interesting negative rake tools

Dennis in Southern Oregon

I notice that he used flat scraping only--no shear scraping. I wonder why he did not use a round shaft so that he would have that option.

Re: interesting negative rake tools

Philip Duffy

WoW! Since Rockwell hardness is a log function ( I am told) that puts the steel out of the roof. I have to ask; Is this steel difficult to sharpen, or can one do it by diamond wheels only? P.

HSS Rockwell hardness

John K Jordan

Thompson says his 10v tools are hardened to 62-64 Rockwell. I don't have a Rockwell hardness tester so I can't confirm. (I wish I did.)

From the Wiki article:

Combining molybdenum, tungsten and chromium steel creates several alloys commonly called "HSS", measuring 63-65 Rockwell "C" hardness.

The addition of cobalt increases heat resistance, and can give a Rockwell hardness up to 67 Min..