Making an adjustable mouth on a wood plane?

[Brian Kent]

I am trying to picture how an ordinary human being could build an adjustable mouth into a shop-made wood hand plane. I have a couple of ideas but would rather try a proven solution.

I am imagining either a knob screwed into the front sole that moves along a slot on the top of a plane body, or a screw through a fixed hole in the plane body that connects to a bolt head in a slot that is a part of the front sole. :confused:

[Robert Rozaieski]

Check Steve Knight's web site. He makes wooden planes with adjustable mouths.

[Joel Goodman]

The ECE reform smoother has an adjustable mouth. Imagine a wooden version of an adjustable mouth block plane -- ie a small piece let into the sole ahead of the mouth which is retained by a machine screw in a threaded insert. The screw goes up to the top of the plane in a slotted hole (for adjustment) and is tightened after the mouth is set. It works fine.

[Brian Kent]

I see that he has a single screw on the front top of the plane body.

I don't know what happens inside and I don't know if it is right to ask since it may be copyrighted or at least where he earns his living.

[Zahid Naqvi]

Wooden planes are relatively easy to make so it might be more productive to make several with the specific mouth openings you need. I think Joel has the right idea for adjustable mouth.

[Clint Jones]

http://linuxplane.awardspace.com/index.html

[Barry Vabeach]

Brian, there are actually 2 different concepts. In metal planes, like some block planes and the LN 62, the adjustment allows you to vary the size of the mouth, usually by loosening a screw and a piece attached to the sole slides forward or back and is then tightened. I have built a sliding sole for a wooden plane I use infrequently, and it wasn't that hard to do, though I didn't think I would use the adjustment very much. The other concept is that with a wooden plane, as the sole is flattened over time the mouth opens. Though some suggest it shouldn't be flattened that much, it is not rare to provide a way for the user to combat the widening of the mouth by inserting a tapered shaped peice lying vertically against the forward part of the mouth, which is what Steve fits to some of his planes. When you first get it, if you think the mouth is too large, you tap the piece down, and the mouth gets narrowed ( because of the width of the taper ) and then you screw it into position and shave the bottom part flush with the sole. If you subsequently remove so much of the sole that the mouth is too open, you loosen the screw and tap the tapered piece down ( and trim the bottom of the tapered piece) until the mouth is the size you want. While this is adjustable, the adjustment isn't reversible, because if you tapped the tapered piece up, you would then have a large hollow at the front of the mouth. It is a great device to get an extremely fine mouth ( say .003 or .004 ) in a fairly short time with no special tools. In my opinion, we sometimes focus more energy on the size of the mouth than it is worth, though others disagree. Barry

[Brian Kent]

http://linuxplane.awardspace.com/index.html

Clint, I've just looked through the plans and pictorial and I want to try one. It adds two other plane features that I haven't tried yet - the abutments and the sculptured wedge to fit the abutments. Looks like a lot of fun.

[Brian Kent]

Barry, I wondered what that front wedge was all about on Steve's planes. It makes a lot of sense now that you explained it.

This started as a question in my mind about an ideal smoother using what I have on hand. My main reason for wanting to try this is to isolate that one factor - mouth opening - and see where I ended up. I've tried it on my metal planes but not wood.

[Barry Vabeach]

Brian, Steve's planes, I have one, have a number of good features - IMO, the thick blade that he offers is a greater contributor to the result than a fine mouth- but the adjustment feature on his plane is ideal if you want to experiment with a very fine mouth. Barry

[Michael Faurot]

I am trying to picture how an ordinary human being could build an adjustable mouth into a shop-made wood hand plane. I have a couple of ideas but would rather try a proven solution.


I've not made one myself, but in the book Wooden Planes and How to Make Them (http://www.leevalley.com/wood/page.aspx?c=1&p=45260&cat=1,46096,46107&ap=1), an example of this is shown in chapter 8. It's done sort of like a Krenov plane where the body has two side cheeks, but instead of those cheeks being flat they'll have rails that look sort of like this, if viewed from head-on:

88973

The front block, instead of being glued between the two cheeks, instead has a groove in it on each side and a an elongated hole through which a screw/bolt can pass to facliitate the adjustment. It would look something like this from the side:

88974

[Brian Kent]

I've not made one myself, but in the book Wooden Planes and How to Make Them (http://www.leevalley.com/wood/page.aspx?c=1&p=45260&cat=1,46096,46107&ap=1), an example of this is shown in chapter 8. It's done sort of like a Krenov plane where the body has two side cheeks, but instead of those cheeks being flat they'll have rails that look sort of like this, if viewed from head-on:

88973

The front block, instead of being glued between the two cheeks, instead has a groove in it on each side and a an elongated hole through which a screw/bolt can pass to facliitate the adjustment. It would look something like this from the side:

88974

So the bolt goes side to side instead of top to bottom?

[Michael Faurot]

So the bolt goes side to side instead of top to bottom?

Right. The whole front block slides back and forth to provide the adjustable mouth.

[Joel Goodman]

Why is this better than the ECE approach? It would seem to me that having a small movable shoe would keep the integrity of the plane body better than having the bulk of the front of the plane slidable. On the ECE the moveable shoe is about 1/4 or 5/16 inch (from memory not measured). If you like I could take apart the ECE and post a few photos.

[Brian Kent]

Joel, the part I can't figure out is how an insert could be fitted into a 1/4" or 5/16" plane. Otherwise the system makes sense.

[Joel Goodman]

I went back and checked the ECE plane -- my bad as the kids say. The moveable shoe is just over 3/4" thick. It has a threaded insert. The shoe is
1 1/2" long and 1 15/16th" wide (the iron is 1 7/8th"). The bolt runs in an oversize hole which is capped on the top by a recessed washer which is slotted to allow the adjustment.

[Brian Kent]

Thanks. I can picture it now.

[Brian Kent]

I made my adjustable mouth plane today, mostly from these plans Clint Jones showed us:

http://linuxplane.awardspace.com/index.html

but with a thicker adjustable mouth so I could use a threaded insert instead of screwing through the moving piece.

I am happy with the plane itself, but only when I borrow a 3/16" thick hock blade from another plane. The 1/8 HSS steel blade I tried first was the wrong blade to use for this design. It needs a cap or steel wedge or something because it chatters a lot.

So I'll borrow a blade for now and pick up a Hock or other thick blade in the future.

Any suggestions (in addition to Hock) for good thick blades that would not need a cap? The plane is 7" with a 1-3/4" blade at 50 degrees.

[Barry Vabeach]

Brian, if you are going to make only a few planes, you could contact any of the custom plane makers, like Steve or Ron Brese and they can help you out. If you are going to make a bunch, you may want to consider buying some O-1 steel and making your own. Victor has some odd sized stuff on sale, their 15/64 x 2 x 18 inches is $9.00
http://www.victornet.com/cgi-bin/victor/productlist.html?subdepartments=Flat+Ground+Stock+ %289%2F64%22+to+1%2F4%22+thick%29%3A1203%2C1531
I assume it would be close enough that it would act like a 1/4 blade and you would get at least 3 and possibly more depending on the length of iron that you want. You would have to do some heat treating, but there is a ton of info on the net and it is a pretty forgiving process and your costs for the intial setup ( for 2 torches, some firebricks, and a gallon of peanut oil should be in the neighborhood of $75 - if you are heat treating 1/4 stock, I would want to use mapp torches - though you might be able to do it with 2 propane torches. ) If you thought that the plane makers are rolling in profit since the material, on sale, is pretty cheap you will learn that there is a lot of extra work in making your own blades , like hacksawing to size, and grinding the intial bevel and flattening the back. If you expect to do 1/2 dozen or less it would make more sense to just buy them, unless you found the work interesting on its own. Barry

[David DeCristoforo]

"Any suggestions ... for good thick blades"

I have made lots of blades from D2 steel. It's cheap and all you have to do to make a blade is cut a piece to length and grind a bevel. I've also made cap irons from it. If you have a few drills and some tap and die sets, it's easy to do. I'm sure the metallurgists among up can offer better advice on hardening and tempering but I just heated the D2 to "bright red" with a torch and let it cool. I never tempered the blades so that they stayed at max hardness. I'm sure there's better steel and much better ways of treating it but I always got blades that were plenty hard enough to take a razor edge, didn't chip and they hold an edge just fine.

[Brian Kent]

Here is the "finished" plane. I made a simpler wedge after the last post and it makes this blade usable. The idea of making blades sounds very interesting. It is really enjoyable to try and discover something new. My mind is spinning on the idea.

Anyway, here is the plane: The fancier wedge is the first one that allowed for all the chatter. The solid one is the wedge that works.

[Brian Kent]

I take it back about it being usable. It is usable-er than before, but not yet up to par. Just now It wouldn't even work with the blade that worked before.:confused:

I plan on going to sleep and letting the wood transform itself into a plane while I rest. Maybe it is like a crystal forming in the depths of the earth. The molecules have to align themselves.

Tomorrow or the next day I will tap a blade and wedge into place and perfect fluffy shavings will magically appear.

Or I'll save up some money and send it Steve Knight. I'll look at his perfect plane in my hands and wonder why I ever tried to do this myself.:rolleyes:

[Barry Vabeach]

Brian,you may already know, fitting the wedge can be time consuming, but if it is wrong you will end up with chatter. I like to put the wedge in place and then use the thinnest feeler gauge I have and test at the bottom and top ( both left and right sides ) An ideal fit is if the there is no gap between the wedge and the iron at the very bottom of the plane and the very top and in between it is either even or you have a gap of a few thousands.