Making a Wooden Smoothing Plane
Making your own plane is a great shop project that results in a fine tool that you will use on a regular basis.
A good metal smoothing plane costs around $350 these days, while the cost of a wooden smoother is essentially the price of a stout blade at $50, plus about $20 for a piece of dense exotic wood. There are several key features that come together to make a smoothing plane work well. Vibration is something to be avoided. We do this by selecting a dense hardwood such as Jatoba, maple, or, if you want to make the plane more interesting, try cocobolo or bocote. All of these dense woods do a good job of reducing vibration. My favourites are cocobolo for its density and beauty, followed closely by bocote for its density and feel.
Lay out your parts
Use a cabinet maker’s triangle to keep your parts oriented in the right configuration throughout the build.
Rout the groove
Use a wooden block as a positive stop for the cut on the router table.
Make your mark
It is essential to accurately lay out the plane's components to ensure proper function.
Keep it straight
The dowel pins will help ensure that all the components stay lined up for the glue-up.
Don’t be afraid of using too many clamps. You want to make sure that the glued surfaces bond well.
Starting with the band saw and finishing with files, shape the rear of the plane to fit your hand comfortably.
Things to Consider
Any smoother must have a sole that is dead flat – within 0.001″ across the sole. It is especially important on a smoothing plane to have the sole touching immediately ahead of the mouth. This ensures that the wood ahead of the mouth is held down, which prevents splitting ahead of the cut during planing. It is true that wooden planes move very slightly with moisture changes, but unless you have a very wet period, the effect on the plane’s performance is negligible. The plane is rather small, so wood movement is not a significant issue. Orientate the grain direction on the plane sole so that it points toward the rear of the tool. This will mean that you are not pushing a tool with the sole fibres pointing forward.
To reduce vibration during cutting, a typical iron will be 3/16″ thick or more, with a stout cap iron to further support the blade. For a smoothing plane, we use a 1 ½” wide blade because the cheeks of the tool add about another ⅝” and we need to be able to comfortably hold the tool. These thick blades are much easier to hone. With wooden planes, we grind the primary bevel at 25 to 30°, and then hone at the same angle. Hone these blades with the heel and toe of the hollow ground primary bevel touching the stone simultaneously – this makes honing simple to do by hand and very repeatable. Make the mouth opening small to reduce tear-out ahead of the cut.
The nice thing about making your own plane is that you can select the plane body material, the bed angle, the mouth opening and the shape of the tool. I have made many wooden planes: smoothing planes, jointers, coopering planes, hollowing planes, scraper planes and tiny one-handed smoothers.
Core and Cheeks
Bed Angle and Front Ramp
Layout Front and Rear Ramp Positions
Dowelling the Ramps into Place
Making the Cross Pin
Note: It is preferable to have 1/32″ of lateral movement in the cross pin, rather than having the shoulders tight between the plane cheeks causing binding.
Using the Plane
Use a plane hammer to tap the blade to increase the cut. Tap the rear of the plane body to reduce the cut depth. Tap the wedge into place using the same hammer. Make sure the wedge touches the cross pin all the way across – if not, file the wedge to get a good fit, which is critical to your depth of cut adjustments.
Your new smoother will give you a lifetime of service. It takes a day or so to get used to making adjustments with a plane hammer, but the results are well worth the effort.