Fraternal twins?

A few years ago a friend expressed interest in stopped by to try a few planes. He was pretty taken with the K9, and over the course of the next several months, we talked about a few changes to the specs. What was interesting to me was that he really, really liked the Boxwood. Not so much because of the way it looked - more because of how it felt. Boxwood is one of the few infill woods that I do not french polish. I soak it in double boiled Linseed oil, let it dry, and then give it a coat of paste wax. I like the way it looks, but also the way it feels, and I think he connected with that feeling right away.

There were a few changes he was interested in. The biggest issue was to further reduce the physical weight. He wanted to increase the bed angle to 55 degrees (mine is 50 degrees), and to make the blade a little narrower - 2" wide as opposed to 2-1/8" like my K9.

Narrowing the blade would obviously reduce the weight, but so would increasing the bed angle. It allows the handle to be moved further forward because the blade is more upright. Pushing the blade forward allows for the footprint of the sole to be shortened - something else he was hoping for.

These were not minor changes, so it took some time to re-think and re-draw sidewall profiles and make new jigs and fixtures. I was really curious to see how these changes would affect the feel of the plane.

I have taken several photos so you can see how they differ. I have them placed on a 1/8" wide ‘beam’ to see where their respective balance points are.
  

The sole footprint of the K9-55 (55 degree bed angle), is 7-15/16" long, while my K9 is 8-3/16". A full 1/4" difference in length. As shown below, the position of the mouth changed, but not by the full 1/4". 

The photos above and below show the difference in handle position, almost the full 1/4" is reflected here.

The different bed angles are very obvious.

The front pad is almost the same size on both planes - the K9-55 is less than 1/16" shorter front to back. 

The moment of truth was weighing both planes. I was a little surprised by how different they are. My K9 is 4.28 lbs and the K9-55 is 3.99 lbs - a full quarter pound different.

In use, they feel somewhat similar - the Boxwood handles certainly help, but the reduced length of the K9-55 and the handle being pushed in further makes it feel more compact (which it is). More compact feels a little more nimble, and on the return stroke, it feels like there is less weight in the toe. This is always a good thing - less weight in the toe means less strain on your wrist. This happens because the hand holding the handle is supporting a higher percentage of the planes weight.

There is a trade off with the higher bed angle. The heavier the shaving, the more resistance you will feel. When taking sub 0.001" shavings though, the feeling is pretty minimal, and I suspect sharpness of the blade will be more perceptible than the higher bed angle. The blade will wear faster with the higher bed angle, but if the work you are doing benefits from the higher angle, the trade-off will be worth the additional time at the sharpening station.

I have always preferred a No.4 to a No.4-1/2, and in some cases - even a No.3 size. I like small smoothers. They are more nimble and much easier to use for an extended period of time. These two planes do not represent a massive jump like a 4 to a 4-1/2, but they feel different enough that I am tempted to see if I can justify making myself another K9. Or maybe I will explore the K8 instead.