sharpening a scraper

[odie]

View: https://youtu.be/dRQz-cnY2gQ

I found myself wholeheartedly agreeing with this video. My scrapers have a very high angle, similar to the video. -----odie-----

 

[robo hippy]

The first ones I ever got were with a set from Craft Supplies. Pretty sure they were all at 70 degree bevels. I have kept them that way. I don't think I have ever tried one with a more blunt angle, other than a NRS to mimic one from Sorby that had an 80 degree bevel on bottom, and 20 or so on top. Their video on that one showed them doing more of a peeling cut where they would drop the handle, rub the bevel, then raise the handle till it started cutting. Can't say that it did any better than any other variation I have used...

robo hippy

 

[John Torchick]

Interesting video. Thanks for posting. Don't have scrapers....yet. It's on the list.
Noticed the reference to Montana. Did you move or just hoping to strike it rich?

 

[Bill Boehme]

?.... Noticed the reference to Montana. Did you move or just hoping to strike it rich?

I believe that Odie has been in Missoula, Montana for at least as long as he has been on the forum. He is just being cute about his location. His avatar does sort of looks like an old prospector, but he needs a mule looking over his shoulder .... you can't be a real prospector if you don't have a mule.

 

[odie]

The first ones I ever got were with a set from Craft Supplies. Pretty sure they were all at 70 degree bevels. I have kept them that way. I don't think I have ever tried one with a more blunt angle,

Howdy Robo.......I think there are quite a few turners who don't have such a steep angle on their scrapers. All is good by me, but I did identify with the comment in the video about the steep angle supporting the bur. It may prolong the life of the bur, as well......that is worthy of a discussion, me thinks. For those of us who also raise a bur on carbide (Veritas), it also may be of some benefit, for the same reason.

Note: I did feel the tool rest was too far away from the workpiece, in the video. It'll work that way, but closer is better for control, if that option is available to you.....

-----odie-----

 

[odie]

I believe that Odie has been in Missoula, Montana for at least as long as he has been on the forum. He is just being cute about his location. His avatar does sort of looks like an old prospector, but he needs a mule looking over his shoulder .... you can't be a real prospector if you don't have a mule.

Hey now........I do have a mule, and I named her "Jeep"!

-----odie-----

 

[Lamar Wright]

I bought a scraper from Crown a few months ago and it came with a 80 degree bevel and I like it very much. Really enjoyed the video Odie.

 

[John Torchick]

After looking at his avatar, the hat resembles Gabby Hayes.
Trivia- Gabby Hayes was the first movie star to have a beard.

 

[Fred Belknap]

I tried several different angles on my scrapers. I settled on 80 degrees and most of them are NR. I use a RoboRest and use the most acute angle for the top side which is around 25 degrees. I really like the round nose scraper I got from you.
During the VietNam ere we called that kind of hat a "Go to Hell Hat".

 

[john lucas]

I measured mine this morning. It's a negative take ground like a skew except it's a round nose scraper. The angle is the same on both sides so when the burr wears of which is fairly quickly I just flip the tool over and one pass over the grinder and have a new burr. Mine is 78 degrees.

 

[odie]

I measured mine this morning. It's a negative take ground like a skew except it's a round nose scraper. The angle is the same on both sides so when the burr wears of which is fairly quickly I just flip the tool over and one pass over the grinder and have a new burr. Mine is 78 degrees.

Now, that is an interesting concept, John.......flipping the tool over and regrind. Is this your own idea, or did you learn that from someone?

I don't know for sure what the angle on my scrapers are, but it's close to 80°......now, I'll have to go check, so I'll know what the hell I'm talking about!

The wolverine platforms are set to one angle, and stay there for all my scrapers. There are two platforms, and both are modified to a half moon shape. (Oneway is missing the boat to not make some in this shape! ) One is much smaller, and I made it out of a standard size platform......this was done long before they introduced the smaller platform that is available now. It's much better for those scrapers that are short, from grinding a thousand times!

-----odie-----

I'm headed out to the shop now, to get a pic of the modified platforms, and to measure the angle on my scrapers.......stay tuned!

 

[William Rogers]

i'm a little confused on the negative rake scrapers angles. I am under the impression that the angles of negative rake scrapers should be 90 degrees or less combined. I thought I read this in a post somewhere. So a scraper with an angle of 80 degrees should only have a 10 degree top angle? If I am reading correct John's and Fred's scrapers exceed that. Is this 90 degree "rule" true or not?

 

[odie]

OK, my scraper angle is 79 degrees.

Here's photos of the modified platforms:

 

[John Torchick]

I believe Cindy Drozda has a platform similar to the one on the left- a notch cut in the platform. Looked at her video just yesterday.

 

[Dave Fritz]

i'm a little confused on the negative rake scrapers angles. I am under the impression that the angles of negative rake scrapers should be 90 degrees or less combined. I thought I read this in a post somewhere. So a scraper with an angle of 80 degrees should only have a 10 degree top angle? If I am reading correct John's and Fred's scrapers exceed that. Is this 90 degree "rule" true or not?

William, I had the same question of Dave from D-Way when I got a negative rake scraper from him. It was ground 70 degrees on the bottom and 25 on the top. He basically said it works for him. I've found I like it because my scrapers are all ground 70 so I don't have to use much of my feeble brain to remember to change the platform. I rarely sharpen the top, rather either hone the bottom or occasionally grind it to raise the burr.

 

[RichColvin]

flipping the tool over and regrind. Is this your own idea, or did you learn that from someone?

Odie,

We had Tom Wirsing (past president of the AAW) speak at our club. He does the flip approach, but he grinds his negative rake scrapers at 22.5 deg each side (45 deg included angle). Works well for me.

Kind regards,
Rich

 

[Clifton C]

Assisted Curt Theobald ( curttheobald.com ) at Arrowmont in 2014, where I learned the flip technique. Mine ended up being 23 degree per side. Not sure a degree or two makes much of a difference. I use the grinder burr but find there are times when I like to hone, and raise a burnished burr. On end grain boxes, the wispy shavings and finish off the tool make me smile. Not a roughing or hogging tool, I still like my 70 degree scrapers, but N/R scrapers have a place in my arsenal.

 

[Randy Heinemann]

So, is there any concensus as to whether making the scraper’s ground angle blunter than 70 degrees is useful to or it doesn’t matter.

 

[hockenbery]

Tom Wirsing (past president of the AAW) speak at our club.

Tom is an all around great guy. Gives everyone another reason to head for Raleigh next summer to see his demos at the AAW Symposium.
Two on platters
Two on tool steels and grinders with an emphasis on the newer technologies

 

[odie]

So, is there any concensus as to whether making the scraper’s ground angle blunter than 70 degrees is useful to or it doesn’t matter.

As with many/most things woodturning, you probably won't get universal consensus. Techniques, procedures, technical data.....among other things, are all subject to how any individual turner develops, and gets results.

I have evolved to the 80+/- bevel, because I've decided that's what gives me the best results.....

-----odie-----

 

[Glenn Lefley]

Howdy Robo.......I think there are quite a few turners who don't have such a steep angle on their scrapers. All is good by me, but I did identify with the comment in the video about the steep angle supporting the bur. It may prolong the life of the bur, as well......that is worthy of a discussion, me thinks. For those of us who also raise a bur on carbide (Veritas), it also may be of some benefit, for the same reason.

Note: I did feel the tool rest was too far away from the workpiece, in the video. It'll work that way, but closer is better for control, if that option is available to you.....

-----odie-----

I had a well known woodturner teach me to sharpen my scrapers up side down. Creates better burr and the step angle supports that burr.

 

[Mike Johnson]

I tried sharpening my lathe tools upside down but I kept falling over and it made me dizzy trying to stand back up.

 

[Randy Heinemann]

As with many/most things woodturning, you probably won't get universal consensus. Techniques, procedures, technical data.....among other things, are all subject to how any individual turner develops, and gets results.

I have evolved to the 80+/- bevel, because I've decided that's what gives me the best results.....

-----odie-----

Just wondering if better results and less possibility of the tool being grabbed by a blunter angle than 70 or if it’s more related to technique and position of the tool at the time me.

 

[robo hippy]

First, NRS's... There are two different kinds. The first were skew chisels, and this type have the same grind on each side, from 22 1/2 to Glenn Lucas's 33 1/2 degrees. Convenience of this type is you flip it to refresh the burr. This type works best if it is kind of round nose or ) nosed rather than more of a 1/4 round. I can burnish a very light burr on them, but you can hear the edge fracturing, kind of like krinkling celophane, as I burnish the burr. It still cuts though.

The other type is the lower bevel being in the 45 to 80 degree range, and the top being in the 20 to 30 degree range. Most are fine with a grinder burr, but a lightly burnished burr seems to cut better and lasts longer. Best lower angle for a burnished burr is about 45 to 60. For me, the best use of the NRS is in end grain like on boxes, or for sweeping across the bottom of a bowl. I seem to get a cleaner cut up the sides of a bowl with a shear scrape. Burnished burr on a 70 or so degree scraper seems to cut better, most of the time, when compared to a grinder burr. The fineness of the wheel doesn't seem to make much difference. On side grain, it seems that no matter how light of a cut I am taking, since it is still a scraper, I get a rougher surface when using it up the side of a bowl.

Not sure about the steeper bevel supporting the burr better. Though I haven't tried it, at least not yet, I do know that more acute angled scrapers, under 60 degrees, tend to be more grabby. For sure, the burr from CBN wheels is far superior to the one from the more standard grinding wheels.

Jimmy Clewes was a fan of the upside down scraper sharpening. He said it gave a sharper burr. I only played with it a few times. I can't say that it was any sharper, but it didn't last nearly as long as the right side up burrs or the CBN wheel burrs. He did not have CBN wheels at the time but 'was going to get some'. I haven't had a chance to see if he experimented more with the right side up/ right side down since then.

Oh, that ain't a mule, that's a Mazurra Elk....

robo hippy

 

[Glenn Lefley]

I tried sharpening my lathe tools upside down but I kept falling over and it made me dizzy trying to stand back up.

 

[Bill Boehme]

i'm a little confused on the negative rake scrapers angles. I am under the impression that the angles of negative rake scrapers should be 90 degrees or less combined. I thought I read this in a post somewhere. So a scraper with an angle of 80 degrees should only have a 10 degree top angle? If I am reading correct John's and Fred's scrapers exceed that. Is this 90 degree "rule" true or not?

According to Stuart Batty, the included angle should be between 60° and 80°. I think that he uses about 60°. He makes the bevels symmetrical and equal length ... a lot like a skew. The reason for flipping the NRS is to keep the bevel lengths equal. He only sharpens the top bevel which then becomes the bottom bevel.

 

[Donovan Bailey]

First,

Jimmy Clewes was a fan of the upside down scraper sharpening. He said it gave a sharper burr. I only played with it a few times. I can't say that it was any sharper, but it didn't last nearly as long as the right side up burrs or the CBN wheel burrs. He did not have CBN wheels at the time but 'was going to get some'. I haven't had a chance to see if he experimented more with the right side up/ right side down since then.

Oh, that ain't a mule, that's a Mazurra Elk....

robo hippy

Robo Hippy: I had this same discussion with Jimmy Clewes last month. Yes, he still endorses sharpening a scraper upside down because he says that it give a better burr. The other thing he endorses is to sharpen scrapers on a coarser grit bluestone wheel. He claims it produces a sawtooth-like burr which also significantly improves the cut. I tried it...and I think that he is correct. Also, I want to thank you for the Robo Hippy Platform Sharpener...a fine invention (worth double the money) that I use every single time that I turn.

 

[robo hippy]

Coarser teeth cut better and last longer/finer teeth cut better and last longer.... From Mike Mahoney and others to Tom Wirsing and others.... "Less Filling! Tastes Great!" I have used scrapers with the burr totally honed off, top and bottom, and it leaves a very nice finish on sugar maple. I can use a shear scrape with the Big Ugly, very coarse, on dry Myrtle and get the same finish as on the sugar maple, but can't get that finish with the honed off burr..... Just because. As near as I can tell, the 600 grit edge is great for fine finish cuts, but lousy for heavy roughing. 80 grit edge/burr is great for heavy roughing, but in most cases not so good for a fine finish shear scrape. Just about any scraper works fine sweeping across the bottom of the bowl, but not nearly as well going up and down the sides... Some times the wood, some times, just because....

robo hippy

 

[John Torchick]

Careful, Donovan, he might send a bill for the difference. This makes me curious about a NRS added to my tool set. I do have a 3/8 bowl gouge, 3/8 spindle gouge plus the usual tools; what would be the advantage of the NRS? Thanks.

 

[Fred Belknap]

Careful, Donovan, he might send a bill for the difference. This makes me curious about a NRS added to my tool set. I do have a 3/8 bowl gouge, 3/8 spindle gouge plus the usual tools; what would be the advantage of the NRS? Thanks.

I consider NRS as finish tools. You can do a nice cut with very little pressure. It won't catch and you can move it in any direction although I think it gets a better cut down hill. It doesn't require the skill and control that a gouge requires so it can be use in places that a gouge would be hard to use. It is a good tool for reducing the time spent sanding which is always a plus for me. If you think I like NRS , you are right.

 

[John Torchick]

I thought so! Thanks.

 

[Donovan Bailey]

Careful, Donovan, he might send a bill for the difference. This makes me curious about a NRS added to my tool set. I do have a 3/8 bowl gouge, 3/8 spindle gouge plus the usual tools; what would be the advantage of the NRS? Thanks.

Ha...and I would gladly pay it. His platform has cracked the sharpening code for many many new turners and I appreciate his innovation. In regard to your comment on a NRS, I think that the verdict is now settled in the community that a NRS deserves a place in our tool sets. The advantage is that it is a great tool to make fine adjustments to your work piece (removing tool marks, torn grain, leveling the bottom of a bowl, etc.) all without the concern of getting a catch. There a bunch of good videos on the NRS on YouTube that you should review to see how it operates and how to sharpen it. I use a NRS just about every time that I turn now.

 

[Donovan Bailey]

Brendan Stemp has a good body of video work on YouTube and one of the videos was a good instruction session on using and sharpening the NRS. I was going to post it up here as part of this discussion but it looks like all of his videos have been removed from YouTube now. Anybody know what happened to him?

 

[robo hippy]

Yes, the NRS is a very light finish cut tool. I do prefer the burnished burr to the grinder burr, in part because it seems to cut the same, and it lasts a lot longer. For sure they still cut better if you follow the grain rather than if you go against the grain. I have done a little experimenting with them on curves on spindles. It does get rid of tool marks, but clean surface cuts depend as much on the wood type as any thing else, at least at this point...

robo hippy