negative rake scraper

[smiife]

Hi guys,
I have heard a lot lately about negative rake scrapers,!
So I found a square ended scraper and thought about
making it in to a n.r. scraper, this is what I have come
up with , but not too sure if the bevel is at the correct
angle or if there is a correct angle? It looks to be about right
at 60ºon the bottom and 15º on the top,
Any thoughts and/or advice would be appreciated

[pommyphil]

Yes I did one too but I ground mine like a big curved skew, same bevel on each side so I can turn it over. Works well in some applications,IMG_20160417_173932.jpgIMG_20160417_174014.jpg sorry about the flash. Phil

[Cliff Rogers]

I have one made from a Sorby 1" skew I found in a sale bin for $10, it is my favourite scraper.

[smiife]

Yes I did one too but I ground mine like a big curved skew, same bevel on each side so I can turn it over. Works well in some applications,IMG_20160417_173932.jpgIMG_20160417_174014.jpg sorry about the flash. Phil

Hi phil , so the angle should be the same on each side ?
I made It round so the corners didn, t catch, thanks for your thoughts

I have one made from a Sorby 1" skew I found in a sale bin for $10, it is my favourite scraper.

Hi cliff,
I bought this one from the market place, It is a sorby 1"
just got to make a handle and I will give It a test run

[Sawdust Maker]

what are the alleged advantages?

[Mobyturns]

what are the alleged advantages?

Like all new wood turning tools - it magically transforms you into a better turner.

Seriously though a NRS does have a place in wood turning not only for smoothing out ridges off the gouge but also in refining the surface to minimize the amount of sanding required. Once a turner understands how to use the NRS, when a burr is required & when it is not required it can significantly reduce sanding effort and over come a lot (not all) of tear out issues.

[george mavridis]

Like all new wood turning tools - it magically transforms you into a better turner.

Seriously though a NRS does have a place in wood turning not only for smoothing out ridges off the gouge but also in refining the surface to minimize the amount of sanding required. Once a turner understands how to use the NRS, when a burr is required & when it is not required it can significantly reduce sanding effort and over come a lot (not all) of tear out issues.

Wouldn't you get the same results using a normal scraper and just lifting the handle so the presentation is at a negative angle?

[Cliff Rogers]

what are the alleged advantages?

NFI, it is just my fav scraper.
It was a total accident on my part.
I didn't want to waste steel when I ground it round so it ended up with some of the skew bevel left on the end & it just worked a treat for me.

[Cliff Rogers]

Wouldn't you get the same results using a normal scraper and just lifting the handle so the presentation is at a negative angle?

Yup.

[Mobyturns]

Wouldn't you get the same results using a normal scraper and just lifting the handle so the presentation is at a negative angle?

George, not quite the same. It is more about the included angle of the cutting profile. Look up Stuart Batty's opinion on NRS geometry. We still have a lot to learn & understand why the NRS profile works. Guilio Marcolongo uses a NRS (i.e. a skew chisel) for hollowing end grain boxes.

[turnerted]

In addition to what Mobyturns said ,it is virtually impossible to get a catch . I ground mine both sides the same , but I found that I use them more one side than the other so after a while the two sides are unequal .It seems to make no difference . Just be prepared to sharpen frequently.
Ted

[Mobyturns]

Yup.

Cliff, my original thoughts were the same, however the NRS does not self feed the same way a traditional scraper does when held in trailing mode (i.e. lifting the handle.) I have used a standard skew as a NRS for years as a shear scraping tool on the outside of my small linlam bowls, and a curved skew (Lacer style profile) on the inside. Definitely do not get the same levels of harmonics on thin walled bowls out of kiln dried or very dry timbers that you would experience with a traditional scraper profile. In fact a traditional scraper in trailing mode self feeds and destroys those little bowls almost instantly. The NRS works well for me in that application.

ps I used a modified Sorby tear drop scraper (RS222) insert on the Sorby handle / shaft prior to the NRS. The NRS solved all of the issues I was having with harmonics.

[Cliff Rogers]

Only difference that I can see is that you don't need the tool rest so high to get the Neg Rake.

What ever it is, it is my fav scraper & it works for me.

[Mobyturns]

Another benefit in converting a traditional curved scraper to a NRS with equal bevels is that you only require one tool and not two - one for inboard (8007) & one for out board turning (8007LH) or turning in reverse if you feel inclined to do so. Only need to flip the tool and create the burr on the opposite side.

[Cliff Rogers]

I tend to use mine for inside & use the bottom wing of a bowl gouge rolled on its side on the outside.