Wooden smoother mouth opening

[James Scheffler]

Help! I'm making a wooden smooth plane, and I'm at the point where I'm filing the mouth opening to admit the blade. The blade is bevel down. Bevel angle is 55 degrees. I'm trying to make the mouth pretty tight.

So the front ramp of the mouth can be filed 90* to the sole, angled roughly parallel to the blade, or angled counter to the blade. I have two references the seem to be offering conflicting advise. The only wooden plane I own (an antique jack plane) has the mouth wide open and roughly parallel to the blade.

What's the best way to do this?

Thanks in advance....

Jim

[Casey Gooding]

I file my openings either 90* to the sole or angled slightly away from the blade. Works great on all the woodies I've made.

[Matt Evans]

I would go with a 90 degree approach, parallel to the blade. You aren't going to file that much if you are keeping the mouth tight, so you shouldn't have to much of a problem with chips clearing the mouth. If the filed area at 90 degrees is a bit big and you have chip clearing problems, start angling it from the top of the filed area, a little at a time, until you no longer have the problem.

If you angle the front of the mouth to strongly the mouth gets weak, and will chip with use, which results in a large mouth opening.

I don't know if that helps or not. If you have CAD I can show you a drawing of what I mean.

[Robert Rozaieski]

Traditional wooden planes (not the Krenov style) typically had the wear (the lower front of the throat) at about 60 to 75 degrees from the sole. This was to limit the amount that the mouth would open with subsequent truing. The problem with making the wear 90 degrees or leaning toward the toe of the plane is that as you maintain the sole of the plane, you will continue to make the mouth wider and wider. Having the wear at 60 to 75 degrees lessens the effect. The lower the angle, the less the mouth will open with subsequent truing of the sole but the easier the throat will tend to clog.

The top front of the throat would be angled away from the iron, toward the toe to allow access for the shavings to eject from the throat.

Here's a couple of diagrams from Leif Hansen's web site that might help.

http://www.norsewoodsmith.com/drupal/files/image/benchplane/cutaway2.gif

http://www.norsewoodsmith.com/drupal/files/image/benchplane/ANGLES2.jpg

[Matt Evans]

Go with Bobs suggestion. It makes the most sense.

I had thought you were just trying to open the mouth a bit, until I reread your post.

Bob, do you know if any of the transitional planes had that angle? I know none of my wooden planes from this era do, but all of my molding planes do. Just got me to wondering.

[Steve knight]

you can get away with even more angle then that. the easy way is make it at 90 degrees and too tight. then file it at an angle to open it up when you have the sole flattened. this is easier then trying to build it with a perfect mouth and gives you room for mistakes.

[Robert Rozaieski]

Go with Bobs suggestion. It makes the most sense.

I had thought you were just trying to open the mouth a bit, until I reread your post.

Bob, do you know if any of the transitional planes had that angle? I know none of my wooden planes from this era do, but all of my molding planes do. Just got me to wondering.

Not sure Matt. I've only ever owned one transitional and sold it some time ago. I don't remember the mouth on it but I don't think it had the compound wear and top of throat angles. For some reason I visualize it with a straight 90 degree throat from the sole to the top but I honestly don't remember for sure.

[Matt Evans]

The transitional plane I just posted for sale with the parts had a 90 degree mouth, but I thought that I had had one a few years back that had the angle. But, it was a while ago, and I am not sure if my memory is playing tricks on me, hence the question.

[James Scheffler]

you can get away with even more angle then that. the easy way is make it at 90 degrees and too tight. then file it at an angle to open it up when you have the sole flattened. this is easier then trying to build it with a perfect mouth and gives you room for mistakes.

That's about where I am now. The sole is flattened and the front block now has a small flat 90 deg to the sole. The blade can't go through yet. I'm going to try to file it back at about 75 deg to the sole as suggested by Robert above until the blade can just go through.

Hopefully I'll have photos to post in a day or so!

Thanks,
Jim

[Derek Cohen]

Keep in mind that another way of breaking through for the blade is to lap the sole. The advantage of this is that you can also fine tune the angle of the bed to the sole (is the blade parallel with the sole?).

http://i13.photobucket.com/albums/a262/Derek50/Articles/While%20Glue%20Dries/Smoothing.jpg

Regards from Perth

Derek

[James Scheffler]

you can get away with even more angle then that. the easy way is make it at 90 degrees and too tight. then file it at an angle to open it up when you have the sole flattened. this is easier then trying to build it with a perfect mouth and gives you room for mistakes.


Hi Steve,

At the time I started working on my smoother, I didn't realize you are now offering kits at such attractive prices. Your smooth plane kit isn't all that much more expensive than my LV blade + lumber, and it would have saved several hours of labor! In addition, the lumber lookes nicer than mine and the iron is thicker. Something to think about for the future, I guess.

Thanks,
Jim