Thread: High angle planes???

Yes it will be more durable, however having a harder iron will give you a more durable edge even if the angle is only 30º. I also think that 30º is a better angle because when you flip the blade you get 90ª scraper anything more then 30º you are going 90º+.

TA

There is a problem with the set up you describe. Essentially, you will struggle to get shavings.

While you are correct that the angle of attack/cutting angle for a bevel down plane is taken from the angle of the bed, which means that this here will be 60 degrees, the problem is that the blade edge will not be "sharp".

I use two terms when defining "sharpness". One is the smoothness of the bevel edge (hence use higher grits to hone), but it is the other term that is relevant here. This is penetration. Penetration refers to the ease that an edge can enter the wooden surface. The more acute the angle, the greater the ease of penetration, and the "sharper" the edge will appear.

For example, which would you balance on the palm of your hand, a knife point or a square edge?

So the 45 degree edge will not have the penetration of a 30 degree edge.

When LN first brought out their replica of the Stanley #112 scraper plane, the blade was bevelled at 60 degrees. They eventually began to offer it at 45 degrees. I now hone my #112 at 30 degrees. This does not hold an edge as long as 45 degrees, but it gets much sharper (and cuts better).

Regards from Perth

Derek

Originally Posted by derekcohen

So the 45 degree edge will not have the penetration of a 30 degree edge.

Hi Derek,

Do you think the same is true of blades used in bevel-up planes? For example, do you think achieving a 60 degree angle of attack with a bevel up plane, by grinding/honing a 48 degree bevel to go with a 12 degree bed angle, is less effective than using a HNT Gordon plane with the 30 degree bevelled blade bedded at 60 degrees?

Do you think the same is true of blades used in bevel-up planes? For example, do you think achieving a 60 degree angle of attack with a bevel up plane, by grinding/honing a 48 degree bevel to go with a 12 degree bed angle, is less effective than using a HNT Gordon plane with the 30 degree bevelled blade bedded at 60 degrees?

Ian, I think that is an excellent question! I don'thave the definitive answer because, in practice, both work. However I don't think that they are equivalent conditions since the bed angles are different. I know that the wood cannot tell the difference between a BD and BU configuration. Perhaps this is another factor why the increased wear bevel on BU planes affects them more than on a BD plane? That is, the BU edge works but not for as long as a BD edge (which has a more acute bevel for the same cutting angle).

I must have a read of Leonard Lee's text and see what he has to say.

What's your take on this?

Regards from Perth

Derek

Thanks for the reply Derek.

I don't know the answer either.

I've never used a HNT Gordon plane and I've never used a planing angle as high as 60 degrees. I've used bevel angles as high as 40 degrees in my bevel up planes to achieve planing angles of 52 degrees but I've never tried to compare this to the performance of bevel down plane. The planing angle of 52 degrees works OK and gets the job done so in practice I haven't thought much more about it.

Originally Posted by derekcohen

Ian, I think that is an excellent question! I don'thave the definitive answer because, in practice, both work. However I don't think that they are equivalent conditions since the bed angles are different. I know that the wood cannot tell the difference between a BD and BU configuration. Perhaps this is another factor why the increased wear bevel on BU planes affects them more than on a BD plane? That is, the BU edge works but not for as long as a BD edge (which has a more acute bevel for the same cutting angle).

I must have a read of Leonard Lee's text and see what he has to say.

What's your take on this?

Regards from Perth

Derek

Hi Derek

I wouldn't have thought that the bed angle would have played a part. The clearance behind the edge is roughly the same so for the most part everything 'should' be equal. But I had to re-read a couple times to make sure I wasn't mistaken what you're saying. The the bevel up blade with a 48 degree bevel is less durable than a bevel down blade that has a bevel angle of 30 degrees? Definitely would like to hear more. Is this something Lee Valley has been testing?

Originally Posted by derekcohen

TA

There is a problem with the set up you describe. Essentially, you will struggle to get shavings.

While you are correct that the angle of attack/cutting angle for a bevel down plane is taken from the angle of the bed, which means that this here will be 60 degrees, the problem is that the blade edge will not be "sharp".

I use two terms when defining "sharpness". One is the smoothness of the bevel edge (hence use higher grits to hone), but it is the other term that is relevant here. This is penetration. Penetration refers to the ease that an edge can enter the wooden surface. The more acute the angle, the greater the ease of penetration, and the "sharper" the edge will appear.

For example, which would you balance on the palm of your hand, a knife point or a square edge?

So the 45 degree edge will not have the penetration of a 30 degree edge.

When LN first brought out their replica of the Stanley #112 scraper plane, the blade was bevelled at 60 degrees. They eventually began to offer it at 45 degrees. I now hone my #112 at 30 degrees. This does not hold an edge as long as 45 degrees, but it gets much sharper (and cuts better).

Regards from Perth

Derek

Good points

Not too keen on taking 6mm a $110 blade just to satisfy a hunch so I thought I'd get some imput first.