bevel angle for BD hand planes

[Mike Holbrook]

I bought a Veritas Custom 5 1/2 BD plane. Now my mission is to get her ready for service. I bought two PM-V11 blades and I am calculating on how to grind them. I plan to grind a hollow grind on a CBN wheel. One will have a larger amount of camber. One will have a lesser amount of camber. Most of the "camber" in the less cambered blade being at the edges. The two blades will provide me one blade for rough/aggressive use and one for more short jointing type work.

I find it interesting that, at least with the custom planes, Veritas has abandoned the micro bevel. The custom blades come with a 30 degree flat bevel. I am wondering if anyone has experimented with grinding these blades at 25? I ask because I have been grinding all the blades for my Veritas BU planes at 25. I believe 30 degrees is the most popular angle for the thinner Stanley type blades although I realize opinions differ. I did a little experimenting with a 30 degree BU blade. Ultimately I took Derek and others suggestion (25) about the grinding angle for BU plane blades. I assumed the justification for grinding the thicker blades at 25 has to do with the thickness of the blade.

The blades for my custom #4 and #5 1/2 Veritas planes are not as thick as the BU plane blades but they are considerably thicker than Stanley plane blades. They are thicker than the PM-V11 blades Lee Valley sells for Stanley planes too. I am considering grinding the higher cambered blade at 30 and the less cambered blade at 25. My thought being that the rougher use blade might benefit from the steeper bevel and the blade used for less aggressive work might benefit from the more gradual/more delicate bevel. My other option being to just grind both blades at the popular 30 degree angle.

I realize some may not even know exactly what bevel they are grinding by hand, due to the nature of hand grinding/honing. In my case I use a Stuart Batty bevel setter which I have reason to believe accurately sets the table I grind on . Thoughts?

[Patrick Chase]

I bought a Veritas Custom 5 1/2 BD plane. Now my mission is to get her ready for service. I bought two PM-V11 blades and I am calculating on how to grind them. I plan to grind a hollow grind on a CBN wheel. One will have a larger amount of camber. One will have a lesser amount of camber. Most of the "camber" in the less cambered blade being at the edges. The two blades will provide me one blade for rough/aggressive use and one for more short jointing type work.

I find it interesting that, at least with the custom planes, Veritas has abandoned the micro bevel. The custom blades come with a 30 degree flat bevel. I am wondering if anyone has experimented with grinding these blades at 25? I ask because I have been grinding all the blades for my Veritas BU planes at 25. I believe 30 degrees is the most popular angle for the thinner Stanley type blades although I realize opinions differ. I did a little experimenting with a 30 degree BU blade. Ultimately I took Derek and others suggestion (25) about the grinding angle for BU plane blades. I assumed the justification for grinding the thicker blades at 25 has to do with the thickness of the blade.

The blades for my custom #4 and #5 1/2 Veritas planes are not as thick as the BU plane blades but they are considerably thicker than Stanley plane blades. They are thicker than the PM-V11 blades Lee Valley sells for Stanley planes too. I am considering grinding the higher cambered blade at 30 and the less cambered blade at 25. My thought being that the rougher use blade might benefit from the steeper bevel and the blade used for less aggressive work might benefit from the more gradual/more delicate bevel. My other option being to just grind both blades at the popular 30 degree angle.

I realize some may not even know exactly what bevel they are grinding by hand, due to the nature of hand grinding/honing. In my case I use a Stuart Batty bevel setter which I have reason to believe accurately sets the table I grind on . Thoughts?

What frog angle did you order, and do you plan to experiment with lower angles? I ask because that might cause you to add more margin to the bevel angle.

My measurements show that Veritas ships the blades for the custom planes with a 28 deg primary bevel, presumably under the assumption that you'll hone the micro-bevel at 30 deg or greater. Is it possible that your measurement is imprecise by a couple degrees? I suspect they don't add their own secondary precisely because the customizable bed angle makes it hard to choose a single value.

After the last thread I tried increasing clearance on a couple of my BD planes from 10 to 12-13 deg. I did notice a slight decrease in effort, consistent with the measurements Kees presented. I'm not sure if I like it for my own use, though it's certainly beneficial on my 6 y/o's plane.

[Mike Holbrook]

My #4 was ordered with a custom 42 degree frog. I ordered the 5 1/2 with one of the standard angles, 40 degrees. It seemed to me that some of the testing Derek has done with chip breakers might be interpreted to mean that using a chip breaker will allow one to use a lower frog angle without "significant" tear out. I am less concerned with small amounts of tear out, especially if my plane is easier to push while producing larger shavings. I am not looking for a perfectly flat final surface. I am actually happier with a little more "texture'. I also believe that honing a hollow ground blade forms some sort of very small micro bevel. I have not actually done the math to calculate what that bevel is ;-). I just know it seems to work for me.

I have not measured the bevel on any of my Veritas PM-V11 blades. I simply used the information Lee Valley posts on their web site concerning what their custom blades are ground at. Although I believe the text actually says that after honing the user should achieve a 30 degree bevel....so it would not surprise me that as manufactured they might be 28. As I posted above I set my grinding rest using a Batty angle setting device. The Batty setting device is curved where it rests on the wheel, so it rests against the round wheel.

[Curt Putnam]

Absent experimental conditions, for the 45° frog in a BD plane I see no real reason to deviate from 30°.

[Derek Cohen]

Hi Mike

If bevel down at a common angle (45 degrees), use 30 degrees. Others would argue that 35 degrees is better still.

I tested PM-V11 at 25- and 30 degrees in a LN #51 shooting plane (so we are talking end grain here), and the 25 degree bevel did not fare well. The reason it is so successful in a BU plane is that the bed is a low 12 degrees. The higher the bed, the greater the stress on the blade's edge.

One of the reasons I like my Custom planes is that beds are low. This is only possible because of the chipbreaker. Hence, if you are planing interlocked grain and are not willing to use a chipbreaker, then use a high angle plane, either with a high bed (BD) or high included angle (BU). All these planes introduce higher wear on the blades. The BD planes also add greater resistance when pushing. Going for a low angle bed/chipbreaker makes all the good things happen.

Regards from Perth

Derek

[Stewie Simpson]

Derek; I understand the logic of hollow grinding to 25* and then honing to 30* to increase the longevity of the cutting edge on a 45* bd plane; what I don't quite understand is how a fair comparison can be made from tests done on a LN # 51 Shooting Plane that's bedded at 20* , with the added advantage of a skewed blade. As you have stated; "the higher the bed, the greater the stress on the blade's edge."

regards Stewie;

[Patrick Chase]

Derek; I understand the logic of hollow grinding to 25* and then honing to 30* to increase the longevity of the cutting edge on a 45* bd plane; what I don't quite understand is how a fair comparison can be made from tests done on a LN # 51 Shooting Plane that's bedded at 20* , with the added advantage of a skewed blade. As you have stated; "the higher the bed, the greater the stress on the blade's edge."

regards Stewie;

The L-N #51 is bedded at 45 deg, with 20 deg of skew. That amount of skew reduces the effective cutting angle by a couple degrees, but not enough to invalidate wear comparisons IMO.

Perhaps you're thinking of the Veritas Shooter, which is BU with 12 deg bed angle?

[Derek Cohen]

what I don't quite understand is how a fair comparison can be made from tests done on a LN # 51 Shooting Plane that's bedded at 20* , with the added advantage of a skewed blade

Stewy, the #51 is bedded at 45 degrees.

I did extensive tests with different steels at different bevel and bed angles using the Veritas Shooting Plane (BU 12 degree bed) and the LN #51 (BD 45 degree bed). You may be confusing the skew angle of each, which is 20 degrees.

http://www.inthewoodshop.com/ToolRev...tingPlane.html

http://www.inthewoodshop.com/ToolRev...eirBlades.html

Regards from Perth

Derek

[Stewie Simpson]

Thanks Derek and Patrick; the 20* skew angle is where I read it wrong. http://www.henryeckert.com/index.php...ath=39_180_184

regards Stewie;

[Kees Heiden]

Bevel down planes are really pretty forgiving with regards to the sharpening angle. Anything between 25 and 35 is good enough. Even a little higher won't stop the plane from cutting. I am sure there are some differences in the edge endurance, but nothing too radical to loose any sleep.

If the edge fails through chipping and you have a low sharpening angle, then you might want to try a hgher angle.

BTW, with sharpening angle I mean the ultimate honing angle. I don't think the primary makes a lot of difference.

[Mike Holbrook]

Hi Derek,
I must confess there is so much on your site on sharpening and plane testing I have problems relating all the information as well as I would like, but I do refer to it often.

I am all in on the lower angle BD plane beds with chipbreakers. I like the results I see with my custom #4 with a 42 degree frog. I ordered my 5 1/2 with an even lower 40 degrees, which I believe Derek tested with his Custom #7. I fully intend to use the chip breakers on both planes. I have Veritas BU/LA planes if I want to go the single iron path. I have hollow ground all my A2 and PM-V11 BU blades at 25 degrees, except one I ground at 30. They all have some amount of camber. The amount of tear out has not been an issue for me. Now I have the custom planes with chipbreakers if I want to avoid tear out.

I am a fan of lower angle frogs and hollow ground blades. The lower angle frogs, as Derek mentions above, make it easier to push the planes, particularly when taking larger shavings. The cambered blades and low heavy planes help too. It may be that free hand honing the hollow ground blades on the two edges makes enough of a "micro bevel" to help with tear out.

I have two new PM-V11 blades to sharpen and I will probably just hollow grind both at 30 degrees. I started thinking about 35 because I received a Veritas Pullshave yesterday and the A2 blade that came on it is: ground flat at 35, sits in a 45 degree bed with a sole radius of 3 1/2" . Regrinding the curved A2 blade may be a little tricky, with what LV says translates to a 2 1/2" radius on the face of the blade, so I might try it as is before deciding whether or not to hollow grind it at 30. The Batty device I use for setting my tool rest does not have a 35 degree setting. Batty makes another version of his bevel setter that does have a 35 degree and other less used settings.