Crooked Kanna

[Nick Sugihara]

Hi everyone,

I'm hoping some far more knowledgeable woodworkers can offer a bit of advice - this is my first post, so here goes. I recently purchased my first Kanna, and went with the Tsunesaburo Maboroshi 55mm because it seemed like a good entry-level plane. I wanted a smoothing plane and since the Veritas BU smoother is back-ordered until July, I decided to jump into Kanna.

I watched a bunch of Youtube videos and read Toshio Odate's book to learn how to set a new one up, and it seemed to go fairly smoothly. The only problem I'm having is that if I tap it straight in, the blade sits pretty crooked in the dai. I created enough room on the sides that I'm able to knock one side into a fairly straight position but it involves quite a lot of lateral adjustment to get it anywhere close to even in the mouth.

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I get good contact with the bed so I don't think that's the issue - to me it looks like the abutments are very different heights, but I've read enough to know not to touch those. Is this a common problem? Should I try to find a replacement dai or am I missing the issue entirely?

Thanks for any and all help!

[William Fretwell]

Welcome Nick,
Clearly you have jumped in with both feet already! This is the place to ask for sure. I only have have 3 wooden planes, one Japanese, so I’m no expert. Simple geometry says if the blade has to be crooked to get it aligned at the mouth then the frog is not 90 degrees to the bottom or the blade edge is not 90 degrees to the side. I would measure both, lay a ruler on the frog and observe, measure the blade angle with a square. I’m sure someone with more appropriate experience will chime in.

[Justin Kwong]

I too am curious to learn how to fix this issue. I bought a used kanna from flea-bay and it suffers from uneven blade protrusion as well. I am weary of paring away the side grooves because I don't want to introduce too much lateral movement and alter the tight wedge fit of the blade. Sharpening the blade to correct the issue sounds like a plausible course of action. We always try and alter the dai to fit the blade - would it be strange to do the opposite?

[Jason Martin Winnipeg]

This might not be the problem, but have you checked to make sure your blade edge is square?

[Jim Koepke]

Hi Nick and Welcome to the Creek.

Not being a much of a wood body plane user beyond molding planes this will be left to someone else to answer.

Similar problems with metal body planes have come my way and are just as vexing a problem to find where the error lies.

jtk

[Lawrence Burkett]

I think maybe Brian Holcombe is the person to ask. If he doesn't see this thread, you might try sending him a message (on this forum). Let us know if you find a solution.

[Jim Matthews]

https://brianholcombewoodworker.com/craft/japanese-tools/

There are multiple steps to setting up a new plane.

How long was the Dai allowed to acclimate in your shop?

Not for nothing, can you take a shaving as things are now?

[Nick Sugihara]

Hi Jim,

I actually followed Brian's guide for the set-up! Everything seemed to go smoothly aside from the persistent crookedness.

I can take pretty decent shavings with it once I tap it around a bit, but the higher corner tends to dig in and leave a track, unless I drastically skew the blade.

[Howard Pollack]

You could try putting a very thin shim in the loose abutment. -Howard

[Peter McAneny]

Hi Nick
As Brian likely tells you, when setting up a new-to-you kanna, tend to the blade first. The above idea to check if cutting edge is square is on the right track, but keep in mind that the sides of kanna blades are rarely parallel. I made a small adjustable wood T-bevel to address this exact issue. I hold one leg of the T-bevel along one side of the blade, set the other leg on the cutting edge to capture that angle. Then I flip the T-bevel to the other side and see if the angle between that side and the cutting edge is the same. It needs to be pretty close. Maybe check this before doing much work on the dai. Please let us know what you find.

[Jim Koepke]

Hi Peter and welcome to the Creek. Glad to see a new member jumping right in to offer help.

jtk

[Nick Sugihara]

Thanks for the suggestion Peter! I'll give this a try tomorrow and see what we find!

[Nick Sugihara]

First off, thanks so much everyone for your replies!

Okay so I checked that the cutting edge was square, and it was a bit out of square but not enough to cause the level of gapping I'm seeing. Here are two more pictures of what the kanna looks like now with the blade in as well as one of the bed which shows the contact distribution.

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I'm still at a bit of a loss here, perhaps I need to book a Zoom session with a professional.

[Justin Kwong]

Perhaps one side of the bed is lower than the other?

[Jim Matthews]

It looks to me as if the bottom of the Dai is out of plane.

I would want to verify the length of each abutment before going any farther adjusting the blade.
If you have a vernier caliper, measure around the mouth on both sides.

I'm only guessing, but I suspect the Dai is "wedge" shaped, slightly thicker on the side where the blade doesn't protrude much.

[Jim Kepner]

I'm spanking new to the forum and new-ish with kanna so this reflects my own struggles with this problem rather than expertise. I have 4 of kanna in various stages of use and this has been a problem in at least two of the kanna I have. The difficulty is that there are a complex pdf variables that can throw the blade angle off, most of which have been already cited by others: bedding unevenness, opening unevenness, the body being off symmetry, the side slots cut uneven, the blade itself sharpened off angle, the blade being slightly thicker on one side than the other, etc. I've heard of another very experienced person simply grinding the blade to fit the kanna (the My Peculiar Nature blog) I've fussed with all of them except altering the grind of the blade, improving one kanna eventually but almost ruining my first kanna with little improvement of the original problem. I've learned to work around this tendency by side taps so long as the shavings are uniform.
It's taught me 2 major things. One is to be systematic about going through each one of these things before I start shaving wood or grinding metal. The second is not to hinge completion of any project on a new tool! Most of my mess-ups have been from not realizing how much patience, time and care it takes to set up and get to know these tools. I'm probably saying stuff you already know, but I have to keep repeating it to myself as my impatience frequently causes me to bypass this. Oh well.
I'm hoping to see an analysis by an expert and maybe Brian Holcomb will respond and enlighten us both!

[Jim Matthews]

It's taught me 2 major things. One is to be systematic about going through each one of these things before I start shaving wood or grinding metal.

I'm probably saying stuff you already know, but I have to keep repeating it to myself as my impatience frequently causes me to bypass this.

Both notions bear repeating.

[Nick Sugihara]

I appreciate the insight into your own experiences Jim. I definitely made the mistake of purchasing this kanna with the intention of using it on a project immediately. Instead I have myself a second project - not the worst thing.

[Jim Koepke]

It's taught me 2 major things. One is to be systematic about going through each one of these things before I start shaving wood or grinding metal. The second is not to hinge completion of any project on a new tool! Most of my mess-ups have been from not realizing how much patience, time and care it takes to set up and get to know these tools. I'm probably saying stuff you already know, but I have to keep repeating it to myself as my impatience frequently causes me to bypass this. Oh well.


+1 on the bears repeating.

And a welcome to the Creek Jim.

jtk

[Justin Kwong]

The second is not to hinge completion of any project on a new tool! Most of my mess-ups have been from not realizing how much patience, time and care it takes to set up and get to know these tools.

I too, fall victim to this. Setting up japanese tools definitely can be a project in itself.