Negative Rake scraper: woodturning

Sam Angelo gives his thoughts on using and sharpening the Negative Rake Scraper. He talks about angles and the burr.

[@MikeWaldt]

Great video Sam, and thanks for the shout out, I really appreciate it. The whole point of our videos, in my opinion, is to encourage people to think and contribute. Not all things will be agreed upon, but all things should be tried, to see if it suits you, if not, nothing lost :). You have certainly given me lots of food for thought, and I love my food let me tell you! Thanks again for sharing your vast experience. Take care Mike

[@Trees2Pens]

Thank you for the info. Mike is an extraordinary turner.

[@WYOMINGWOODTURNER]

Yes he is and a lot of fun to watch. Sam

[@AsWoodTurns]

Nice complement to Mike's video. Thank you Alan

[@WYOMINGWOODTURNER]

Thanks Alan

[@TheTinyTrailerWorkshop]

Hello Sam: I think you nailed it with it being your tool... sharpen it the way that works for you. I have watched Mike's videos and actually reground a scraper to try it... I can see where there would be times it would be the best tool around... but then there are still lots of times for a regular scraper! I think that you are both right... it's another tool in the arsenal! Thanks for sharing your thoughts... Larry

[@MikeWaldt]

Totally agree Larry, there are specific times when a certain tool will do the job, the NRS has its place, and is a useful addition to the family, but an addition is all it is, not the wonder tool that can do everything, apart from the Skew when in your hands ;) Take care Mike

[@petecy9592]

very nice video sam

[@cillyede]

I learned a lot! Thanks.

[@WYOMINGWOODTURNER]

Thanks Sam

[@HarryWatts65]

Hi sam: Great video Cheers Harry

[@kevinrees3811]

what cuts best a burr or razor edge?

[@CipsWoodChips]

Thanks for sharing. I have long used a slightly curved skew. I think I got it from watching Alan Lacer. I often scrape with it. Is there a difference between a curved skew and a negative rake scraper?

[@WYOMINGWOODTURNER]

I learned the skew from Richard Raffan videos 25 years ago. If Richard said jump off a cliff, I would have asked which one. No I think a skew is just the same as a negative rake.....It cuts very clean as a scraper. In my opinion, because the angle is usually more acute than the angle on most NRS. I think the jury is out on lots of these issues. All fun to talk about. Sam

[@georgeoliver9125]

Nice video as always. Do you think you prefer the NRS over the standard? I would be hard pressed to give up the standard, Well I guess I will have to buy another tool. (lol)

[@WYOMINGWOODTURNER]

George I believe the traditional scraper will leave a cleaner surface. The NRS is safer. It must have a burr on it. A point I failed to drive home. There are places inside a bowl or whatever... that is difficult to reach safely with a traditional scraper. So a NRS can be used. All interesting. Sam

[@RevMoose2]

Sam, Some people grinding NRSs now are grinding the top and bottom bevels the same length as well as the same angle. Just wondered if you have tried this and the advantages for how you grind versus this. Just watched

[@WYOMINGWOODTURNER]

Dan, I am not sure. I'm not really smart enough to know if it makes a difference. But I would site Cindy Drozda's tools and how she sharpens her NRS's. She has the top bevel and cutting edge very close to the top of the tool. For me, if it works I won't worry about it. It is about the burr in the long run. Sam

[@blargkliggle1121]

@@WYOMINGWOODTURNER it's not an issue of intelligence, you merely lack the training/education in engineering to be able to make a guarantee. Before I changed to a radiology degree I took several engineering courses, so I have a little insight. The first benefit of grinding the angles is that you decrease the likely hood of a catch, but you know that. Another benefit of the geometry of a double bevel is that it can better absorb impact/shock with out bending or breaking. Notice on the cross section that the negative rake scraper has more material at the cutting edge, this makes it stronger and even allows it to dissipate heat from the edge faster. Another interesting advantage is that you increase the safe cutting angle allowing for aggressive cuts that would send a regular scrapper across your shop. The last major benefit is that you can pull it up to the work if you went in low. With a traditional or sharp angled scrapper need to approach the work at the proper angle or hope the wall takes more damage than the tool. With the angle on the "top" of the blade you can ease into a cut without having it catch. Dan, in regards to your question, it doesn't offer much notable difference as long as the angle is the same. Though if you're interested in having a steeper total angle I would suggest a 1/3 top 2/3 bottom angle like in the video. Stick with a total angle between 50° and 80° and keep the top angle at 30°. I warn you both that I have only a little knowledge of the subject and you know what they say about a little knowledge...

[@WYOMINGWOODTURNER]

@@blargkliggle1121 I had to read this twice....And no I do not have an engineering degree and my math background is pitiful. And I hope I said this in the video. --> A traditional scraper tends to be "self-feeding" while a negative rake scraper reduces the self-feeding aspect. I am not sure if angles are all that important-but having a burr on a negative rake scraper IS. Sam

[@blargkliggle1121]

@@WYOMINGWOODTURNER don't remind me of the math, I thought my brain would melt trying to get through trig. That's one of the reasons I switched to radiology, algebra is about the limit of my ability. The short of it is that it provides better control and less catching, the other benefits aren't that great unless your machining parts on a milling machine for hours at a time. And as you said, the burr is what makes the tool useful.

[@LordQuath]

One of the things I have learned between this video and also from Mike's beginners guide is... when using the scrapers your not suppose to rub the bevel like you would with a gouge. In his "Foundation Course on Woodturning", Keith Rowley points out in law #6 that you should have an angle of less than 90deg between the tool and the work when using the traditional scraper(handle higher than cutting edge). So, when you grind a negative rake on your traditional scraper and engage the work straight on you would no longer need to raise the handle, as the negative rake would guarantee the angle to be less than 90deg.

[@WYOMINGWOODTURNER]

Anthony I think I am with you on what you said in your comment. I like the explanation of the angle with the traditional scraper. I think what Mike was doing in his video was changing the position of the handle (raise or lower?) to find the burr so it would cut. I believe it is hard to get a catch with the NRS. I really like the tool. Sam

[@LordQuath]

I am starting to see the advantages of NRS also. I just don't have enough extra scrapers to play around with.

[@bobdumlao34]

Mike Waldo