More on Boxes.....

[robo hippy]

I went up to Salem, OR last night to catch Jimmie Allen of Boxmaster Tools. He has been friends with Eric Loffstrom for some time, and will be taking over officially for Dave Schweitzer at D Way Tools after the first of next year. Interesting demo, and now I have some more experimenting to do.... Both he and Eric sharpen their NRS's up side down, about a 70/25 degree angles, on a 60 grit CBN wheel. That is kind of contrary to most of what I do. You can't argue with the results though, ending up with a 320 or so surface in sugar maple. The 70 degree bevel on the bottom is more blunt than most people use, and is standard for my roughing scrapers, but the upside down burr is another thing. I had tried them before, and it seemed that the upside down burr vanished more quickly than the right side up burr, and not sure about the coarseness of the wheel.... He uses the NRS as his primary hollowing tool on boxes.....

Hmmmmm, another domino cascade for my brain....

robo hippy

 

[Charlie Knighton]

having trouble figuring this out today....morning brain fuzz.....any pics......320 grade finish would be SLIGHT improvement.....

 

[Jeff Jackson]

I've been sharpening mine upside down for some time now too since I seen him and others from our club do it for some time now. I've also recently been raising the burr by hand like Eric does. The steel Jimmie uses really works great for that. Also for super dense woods like African Blackwood it works best to hone the burr off, 600 grit can actually rough up the surface of the wood!

 

[Dave Fritz]

That's the grind Dave put on the negative rake scraper he sent me. I put the burr on the top, interesting to put it on the bottom. Anxious to see what you come up with.

 

[Tom Albrecht]

RH, you mentioned that demo in another post last week and that lead me to do some research on Jimmie and Boxmaster.
Here is his video with Eric that has loads of thoughtful info for folks that aren't members in the Salem OR club.

View: https://www.youtube.com/watch?time_continue=1&v=YsatMuK1Ei8


My question is the CBN wheel grit he uses --he told me 80, but 80 or 60, that's a whole lot different from the super fine CBN wheels that I have set up. Do you have to use a coarse grit to get that burr?

 

[Emiliano Achaval]

NIce video. Not sure why would you hollow a box with a NRS, I get good results with a 5/8 spindle gouge. I use my NRS mainly for finishing. I will try their angle...

 

[robo hippy]

Well, I have been turning some boxes lately. Love the 3 second drop off type with a 1/2 inch long tenon that Eric does.... The thing with hollowing with the NRS is that it is pretty much catch proof. Jimmie was hollowing a box without looking and commenting that he couldn't do that with a gouge. Well, I can, but that is because I use gouges a lot. I can also do it with a standard scraper for the same reason. I have done a couple using a NRS, and find it kind of slow, and they need sharpening a couple of times to get to the bottom. The main thing I am trying to figure out is if there is any advantage to the upside down burr compared to the right side up burr and the burnished burr. Thus far, the upside down burr seems more fragile than the right side up one, and both, as far as finish cuts are concerned seem to be about the same. Now, have to experiment with the finer grit wheels. My coarse wheel is 80 grit. There are some who prefer a more coarse edge with bigger saw teeth and some who prefer finer teeth.... Not sure. I have a lot of boxes to turn. Trying to organize myself for a box turning video or three.....

robo hippy

 

[Richard Hodsdon]

Watched the YouTube posted by Tom above. Facinating, What I find interesting is that they use M2 steel, which is a standard specification steel. I wonder how Boxmaster tools heat treatment differs from say Sorby. Do they treat and temper to a different hardness. According to Machinerys Handbook Hardness is purely a function of the Carbon content with the quenching and tempering being used to give the steel the toughness, Are they less variable , hardening to a higher Brinell etc. or merely just more consistent (which the major Sheffield manufacturers should have sorted out ). I need to grind one of my scrapers into a NRS and try it.

 

[Emiliano Achaval]

Well, I have been turning some boxes lately. Love the 3 second drop off type with a 1/2 inch long tenon that Eric does.... The thing with hollowing with the NRS is that it is pretty much catch proof. Jimmie was hollowing a box without looking and commenting that he couldn't do that with a gouge. Well, I can, but that is because I use gouges a lot. I can also do it with a standard scraper for the same reason. I have done a couple using a NRS, and find it kind of slow, and they need sharpening a couple of times to get to the bottom. The main thing I am trying to figure out is if there is any advantage to the upside down burr compared to the right side up burr and the burnished burr. Thus far, the upside down burr seems more fragile than the right side up one, and both, as far as finish cuts are concerned seem to be about the same. Now, have to experiment with the finer grit wheels. My coarse wheel is 80 grit. There are some who prefer a more coarse edge with bigger saw teeth and some who prefer finer teeth.... Not sure. I have a lot of boxes to turn. Trying to organize myself for a box turning video or three.....

robo hippy

Looking forward to your findings. Please let us know what you think. Upside down or not?

 

[Jeff Jackson]

Watched the YouTube posted by Tom above. Facinating, What I find interesting is that they use M2 steel, which is a standard specification steel. I wonder how Boxmaster tools heat treatment differs from say Sorby. Do they treat and temper to a different hardness. According to Machinerys Handbook Hardness is purely a function of the Carbon content with the quenching and tempering being used to give the steel the toughness, Are they less variable , hardening to a higher Brinell etc. or merely just more consistent (which the major Sheffield manufacturers should have sorted out ). I need to grind one of my scrapers into a NRS and try it.

They go through the same heat treatment as D-way which is 63 to 64 Rockwell. It was discovered that the m2 actually produces and holds a better burr than the m42, because of the granular structure. But they are much harder than the other brands of tool.

 

[Jeff Jackson]

That's the grind Dave put on the negative rake scraper he sent me. I put the burr on the top, interesting to put it on the bottom. Anxious to see what you come up with.

The burr is still on the top but the presentation to the grinding wheel is upside down, and the tool is angled down to the wheel instead of up as we normally would. The wheel is basically pushing the burr up like it would be with a burnishing tool.

 

[Tom Albrecht]

They go through the same heat treatment as D-way which is 63 to 64 Rockwell. It was discovered that the m2 actually produces and holds a better burr than the m42, because of the granular structure. But they are much harder than the other brands of tool.

So how does all that compare to Doug Thompson's tool steel? In the demo I saw at Robust last weekend with Rudy Lopez, he sells and recommends Thompson's scrapers.

 

[Jeff Jackson]

So how does all that compare to Doug Thompson's tool steel? In the demo I saw at Robust last weekend with Rudy Lopez, he sells and recommends Thompson's scrapers.

I apologize but what I actually what I meant was other brands of m2 steel. I'm not sure what Doug's are but I know they are good to.
I'm sorry I left that out, that was written before coffee this morning. My bad...

 

[robo hippy]

As far as tool steels/metals go, I can't tell any difference in the Thompson V10 and the D Way M42. A friend who has retired from turning myrtle wood trays for the coastal shops for 30 years, about 700 per year, agreed. Larry could give a weather forecast for the next week depending on how his myrtle was cutting....

As for the M2 taking a better burr than M42, I don't know. I didn't buy one of Jimmie's tools because I have a bunch of D Way blanks. Jimmie did way that with their method of heat treating, his M2 gets as hard as the M42. The exact method for heat treating is their secret.

I always figured that bevel up was similar to honing a burr, and I guess the same could be said for bevel down, or maybe we should go sideways... That would be trick grinding. I have a lot more experimenting to do with the burr grinding. Thus far, I have been testing it on the 80 grit wheel. Still need to try 320 and 600, or maybe just skip to the 600. With the standard 70 degree bevel scrapers, I couldn't tell any difference in the burr between 80 and 180 grit. I do find the NRS to be a slow tool for hollowing boxes. When I am using a hollowing tip (Kelton 5/8 shaft, very slight hook and tantung on the end), I do keep it rolled over to the side rather than square. Carbide might be able to outlast the burr on it, but it can be resharpened.

One other interesting note on Jimmie's demo is his tool rests. The bar stock is case hardened, so it slides like hardened A2 drill rod. I have to order one for the mini lathe and one for my Liberty. Small diameter bar, made for being able to hook your fingers all the way around it for stability...

robo hippy

 

[robo hippy]

Oh, I forgot, I saw some where, no idea where, but there are now carbide NRS's...

robo hippy

 

[Mark Jundanian]

I think they are from Easy Wood Tools.

 

[Bill Blasic]

My thoughts are that if the M2 and the M42 are 63 - 64 Rockwell and Thompson's are 60 - 62 Rockwell raising a burr is about the same. I myself use Thompson's ground to a NR (do not know the angles) and they cut in my opinion better than the M2s that I've had and last longer. Nothing scientific here as the only time I use a NR scraper is when I have a very difficult piece of wood with tear out problems.

 

[Richard Hodsdon]

Just had feedback from Sorby, "Our HSS turning tools are hardened to around 62 depending on the type of tool." which is 'softer' than the DWay tools.

 

[robo hippy]

Well, I am curious about the carbide NRS's. Any one try them? I do think that a burr is necessary most of the time, and it has been said that you can't raise a burr on carbide, but since I don't have any of the carbide tools in my shop, I haven't put that to the test, yet.... Oh, I did grow up on the "Show Me" state....

I was out in the shop last night, and on a whim, I put a top bevel on a small Big Ugly tool turning it into a NRS. With a 600 grit wheel burr, I got a glass smooth cut on some end grain Doug Fir. Used an 80 grit burr on some sugar maple, and got almost the same surface. I tried it on the side grain part of the spindle and got a fair surface, but got a better surface using it as a shear scraper. I do have a thing for scrapers though...

robo hippy

 

[Gerald Lawrence]

Well, I am curious about the carbide NRS's. Any one try them? I do think that a burr is necessary most of the time, and it has been said that you can't raise a burr on carbide, but since I don't have any of the carbide tools in my shop, I haven't put that to the test, yet.... Oh, I did grow up on the "Show Me" state....

I was out in the shop last night, and on a whim, I put a top bevel on a small Big Ugly tool turning it into a NRS. With a 600 grit wheel burr, I got a glass smooth cut on some end grain Doug Fir. Used an 80 grit burr on some sugar maple, and got almost the same surface. I tried it on the side grain part of the spindle and got a fair surface, but got a better surface using it as a shear scraper. I do have a thing for scrapers though...

robo hippy

Have a friend who got some of the cutters and they do work as advertised. Not sure I could say they are any better than NRS but they do a good job and seem muck slower than NRS. They do well on end grain also, think the NRS is better on side grain

 

[n7bsn]

Reed's comment on Jimmie's tool-rest reminds me that Ellen had Jimmie make a custom "2-inch" rest ....