Rationale behind Stanley planes' mouth location?

Re: Rationale behind Stanley planes' mouth locatio

ThomD

>I have a design rule, though I haven't come up with a catchy name for it, that states: When a design works just as well in either extreme then it's not a fundamental characteristic. Or something like that

Planes work great whether the mouth is toward an end or in the middle, so the "why" is not really such a big deal. I used to make all my planes, over a certain size, with the mouths right in the middle. I don't know what the Krenov followers thought about it, but they do much the same thing. Some of Krenov's planes are markedly forward, or not.

If one thinks of the plane as a device that puts a longi hollow in a board, then positioning the mouth nearer an end will create a tighter radius or a larger gap when doing natural jointing/flatening. So for instance a 12" plane with .005 blade stick out will plane to a natural radius of 7200 inches if the blade is centered, and 5400 inches if it is tucked 3 inches from an end. Pretty much the numbers you would expect where a guy uses an 18" jointer instead of a 22' or 24" jointer. But I don't know if that is why they do it. It is why I do it. Conversely if you want to knock off some chips, work the mouth out to the ends. Japanese planes can be different where they have a relieved outfeed, though not all do. In particular not those that follow the above geometry.

A simpler explanation is that if you take the main grouping of parts that hold the blade, adjusters, grip, adjustable mouth or bed, and you design a compact model around those parts, then it will have it's mouth forward. Aesthetically you keep that proportion throughout the range so that people don't start asking these kinds of question.

Re: Rationale behind Stanley planes' mouth locatio

Moses Yoder in White Pigeon, MI

>I am looking at a #4-1/2 setting on my desk, and see that the tote is almost flush against the heel of the plane. There is very little room between the tote and the lateral adjust, about 1/8", just enough room for the tote to bend forward some in use without hitting the lateral adjust. The frog mechanism ends up putting the iron in location which is defined by the size of the frog and the tote. The knob has a little bit of room in front of it; just enough to make it look right. So there is no wasted room on a #4 or 4-1/2, or 2 or 3 for that matter. Now if you scale this up to make a #8 or so jointer the mouth would be proportionately about 2/3 of the way forward on the plane. You see where this is headed; the position of the mouth on Stanley planes was based on what they thought would look about right, and probably not at all based on function. On the other hand you only need enough flat in front of the iron to start the plane straight and you will soon have more of the plane on the wood but you need a fairly long heel area to keep the plane straight as the iron gets to the end of the board.