NRS angles and details

[Bill T Tucker]

Having read many discussions on Negative Rake Scrapers...
Having watched knowledgeable demonstrators do amazing things with them...
Having tried various configurations with limited success...
The following questions are asked:

Does the included angle need to be less than 90 degrees and why/why not?

What "top angle/bottom angle" do you prefer and why?
Do all of your NRS have this same grind, if not why?

How do you raise a burr and how long does it last?

Finally, has anyone tried to raise the burr by grinding upside down with the handle up and edge down?

Thanks everyone for considering this and sharing your information and opinions. Any pics and drawings would be greatly appreciated (JKJ), as some of us are slow learners.

 

[robo hippy]

There is a whole thread on this on page 2 about Raising a burr on a NRS.

robo hippy

 

[Bill T Tucker]

Thanks Reed. Didn't read it closely enough and then promptly forgot some of it. Just read it again...lot of information there.

 

[Brian Horais]

Bill, sorry for the delayed reply. I understand that the included angle needs to be less than 90 degrees so that you can establish a good burr when sharpening. I took one of the thick single edge scrapers and created a two-sided negative rake scraper. It took a lot of grinding, but the initial work was done on my old shop grinder (lots of stops to cool down the metal). As to the angles, the top angle on my NRS is the 'steepest' angle and the bottom angle matches the grind angle for my roughing gouge. That way I already have the grinding ramp set to a very useful angle and can do touch-up grinding on the NRS frequently. My slow speed grinding setup is right behind me when I turn, so it is easy to turn around and give the NRS a touch-up. Here's an image of my NRS (one of my favorite tools).

 

[Bill T Tucker]

Thanks Brian...am still figuring out a simple repeatable system

 

[Brian Deakin]

you may find the link below informative

https://www.woodworkersemporium.com/content/NRS-Instruction-Manual.pdf