Limits if a 40 degree bed angle

[Tony Wilkins]

I just ordered a Veritas custom 5 1/2 with a 40* frog. I know Derek Cohen has a 42* frog on one of his planes. And I believe I read someone has tried a 40*. I decided to go with the lower angle since I use mostly straight grained cherry and walnut. I'm thinking it will be a little easier to push for a roughing cut and hoping for a Lille smoother result when smoothing.

so what do you think of the lower angle? Strengths and limits?

I guess that kanna with their usual bed angle fall into this category as well.

[Warren Mickley]

I have used a 42 degree plane for over thirty years and two 44 degree planes for a bit longer. The surface is somewhat smoother than 45 degrees, but probably not enough to get excited about. Tearout is not an issue.

With lower angle beds the clearance angle comes into play. The clearance angle is the difference between the bedding angle and the honing angle. With your plane at 40 degrees, any sharpening over 30 degrees could easily cause clearance problems. A lot of the degenerate steels have problems with chipping unless they are honed at slightly higher angles; I would avoid these steels.

[Tony Wilkins]

I have used a 42 degree plane for over thirty years and two 44 degree planes for a bit longer. The surface is somewhat smoother than 45 degrees, but probably not enough to get excited about. Tearout is not an issue.

With lower angle beds the clearance angle comes into play. The clearance angle is the difference between the bedding angle and the honing angle. With your plane at 40 degrees, any sharpening over 30 degrees could easily cause clearance problems. A lot of the degenerate steels have problems with chipping unless they are honed at slightly higher angles; I would avoid these steels.

Interesting, I hadn't thought about the clearance angle. FWIW I got the PM-V11. Since I got two blades I almost got one of them in O1.

[Robert Hazelwood]

Yes, that's close to a standard kanna planing angle (which is bedded at closer to 38 degrees but the wedge shape of the blade adds a couple of degrees to the actual planing angle).

It leaves a nicer finish than a 45 degree angle, with that effect being more pronounced the softer the wood is. For a given shaving thickness the force required should be a bit less, though it's hard for me to compare because kanna feel much different than a Bailey style plane, and all of my Bailey's/LN's are standard 45 degrees. It will be more prone to tearout, but you can mitigate this with the chipbreaker, which is a huge advantage over a bevel up low angle plane.

If my kanna are anything to go by, it will plane end grain like buttah. Should be excellent on the shooting board.

Getting an appropriate camber on the blade is a little more work, but not as bad as a low angle bevel up plane.

Maybe the biggest issue will be that your maximum sharpening angle will be 30 degrees, including any secondary/micro bevels. Going any more obtuse would begin causing clearance issues. 28 degrees or so would be even better. This is a range in which very hard plain carbon steel blades excel. Something like A2, from my experience, is pretty chippy at those angles, and that would be frustrating for smoothing. PM-V11 seems a bit better, judging from my experience with it in bevel up planes. But this might be an occasion where I'd opt for O1, assuming they offer it for this plane.

But overall I think its a promising idea, and if I had to start over my plane collection from scratch I would probably get something similar.

[Tony Wilkins]

Btw, what angle do the LV blades come with as a primary bevel? All the website says is they need a final honing to 30* so I'm guessing 25*.

[bridger berdel]

One of my on-again-off-again projects is a 30° with chipbreaker infill from a block plane body casting. I recently got it running but still have some mods I'd like to make. It does leave a nice surface from the few test cuts I made with it. It does have an A2 blade in it- we'll see how it holds up in actual use. I expect it will be for soft woods only.

[Christopher Charles]

Tony, thanks for posing this question. I'm gathering funds to upgrade my jointer to a LV custom, in part b/c right now I don't have a decent shooting set up (and can't justify springing for a dedicated shooter in the near future).

Warren, and others, reading between the lines, the minimum recommended clearance angle is 10 deg?

Thanks,
Chris

[Derek Cohen]

With a BD plane you do not want to hone lower than 30 degrees, regardless of the steel. Even with PM-V11, in my experience.

I have a Custom #7 jointer with a 40 degree frog, and a Custom #4 smoother with a 42 degree bed. Both have PM-V11 blades with 30 degree bevels. The 10- and 12 degrees, respectively, of clearance are fine. I obtain good longevity of cutting.

The advantage of the 40 degree frog in the #7 is that it can shoot endgrain. The disadvantage of the low angle frog is that setting the chipbreaker is important, and the lower you go, there is an added sesnsitivity to its placement.

Regards from Perth

Derek

[Warren Mickley]

Tony, thanks for posing this question. I'm gathering funds to upgrade my jointer to a LV custom, in part b/c right now I don't have a decent shooting set up (and can't justify springing for a dedicated shooter in the near future).

Warren, and others, reading between the lines, the minimum recommended clearance angle is 10 deg?

Thanks,
Chris

Yes, ten degrees is a fair figure for clearance. When I did experiments years ago, it seemed that at 12 degrees I was confident that clearance was sufficient; at 8 degrees clearance problems were enough to be noticeable. It doesn't seem to be a threshold where it suddenly stops working, more of a range where clearance gradually becomes a problem. It is probably slightly different depending on the timber or the bedding angle.

A 45 degree frog gives a pretty good cushion to keep you out of trouble. Lowering the frog gives less tolerance for sloppiness.

[Christopher Charles]

Thanks Warren, that's helpful.