Lately I’ve gotten much more interested in using hand tools. I don’t have a real bench though, just an old office desk and there is not a good way to hold a board down flat to work on it. Holdfasts just don’t work well with an office desk, and the desk doesn’t have any structure to support a tail vise.
So I made an 11×48 inch planing board. It clamps easily in the bench front vise, or in a Work Mate out in the driveway. The bed is made of 5/8 Birch plywood, with 3/4 inch holes every 2 inches down a rigid spine, and there is a wide stop screwed to the left end. I researched several different methods of constraining a board. The most promising was the Veritas “Wonder Pup” but it looks awkward to tighten, is 3/4 inch tall, made of plane blade unfriendly metal, and is not cheap.
I worked out a cam arrangement to secure the work but found it takes a pair of cams to cover the 2 inch range.
In this photo the larger cam is lying on the bench at rear along with the plywood spanner wrench used to torque the cams. A pine board is locked by the smaller of the two cams which has a range of 1 to 2 1/4 inches. The larger cam has a range of 2 to 3 1/4 inches.
The Planing Board on the Bench
In the next photo, you see the small cam locking a board. There is an aluminum follower that slides underneath. A tapered wood wedge is screwed to the face of the follower which helps to keep the cam from loosening.
I initially thought I could just use the cam against the work piece. It would tighten (with some difficulty), but if the work wiggled even slightly the cam would rotate and release. Next I made the aluminum cam follower captured by the central peg, which worked better but still loosened too easily. Finally I added a ramp to the follower. It changes the point of contact so clamping force tends to tighten rather than loosen the cam. This works much better, though the thickness of the follower does add a bit to the half inch height of the cam.
The spanner wrench is just quarter inch dowels in a bit of scrap. The wrench has two sets of pins at 90 degrees to each other because the cams have about a 225 degree swing.
The Cam Lock
I don’t have to use the left end planing stop, I can put a 3/4″ peg in any one of the holes and pin the work with the cam. The next photo shows a board locked cross grain using the larger cam.
One problem is the large cam overhangs the edge in some situations, possibly interfering with the plane. If I had to do it over, I would build the spine an inch closer to the sled center. I have also added many more holes for additional short pegs, see later photos.
Large Cam Working Against a Pin
Showing the whole planing board. I spent a lot of time drilling holes, then sunk a 2 inch screw between every pair of holes for strength. It is quite rigid when the vise is snugged up, and more importantly, FLAT.
A Board Pegged in the Planing Board
Here you can see the cam follower, large cam upside down, spanner wrench, small cam, and a peg in one of the holes. I made two sets of cams, one works clockwise, the other counterclockwise. This photo shows the counterclockwise set but I mostly use the clockwise arrangement. Sometimes switching the cam sense will work around a plane interference problem.
Peg holes are 3/4 inch blind drilled 2 inches deep, then 1/2 inch drilled through. This stops the pegs but lets shavings fall through. You can also stick a screwdriver up through the half inch hole to push out a stubborn peg.
This is a picture of the clockwise cams, the profile was refined using this spreadsheet: Cam. If you decide to build a board like mine, you can scale and print this as a pattern. Shape and size are not critical as long as there is sufficient range (> one inch) between smallest and largest radials. The range of the two cams overlap a small amount.
Large and Small Cam
Large Cam 5 3/4″ x 4 5/8″
Small Cam 3 7/8″ x 2 7/8″
And here is a photo of the clockwise cam follower. It is made of aluminum cut from a box lid from my junk pile. the two legs are 3/4″ apart, they straddle the cam dowel so the follower is constrained to move mostly in the direction of the work but can still angle a bit to conform to a board that isn’t square.
2 3/4″ x 5″
Here you can see how the plywood wedge attached to the follower works. It moves the point of contact between cam and follower to a point just past the centerline. Back pressure from the work then tends to rotate the cam in the direction that tightens. If the wedge was not there, the point of contact, because of the spiral shape of the cam, would be just before the centerline and the cam would tend to loosen from back pressure. Also there is a fair amount of friction between the cam dowel and spine holes which helps keep the cam in place
Showing Cam Follower Offset
The fixed planing stop protrudes 3/8 inch above the sled surface at the left end. It is held with screws and can be moved to the right end if necessary. To plane stock thinner than 3/8″, I put hard board spacers underneath the work.
The Planing Stop
In this bottom up photo, you can see the spine made of two 2 inch strips of 5/8″ thick plywood laminated together. It provides overall rigidity, meat around the peg holes, and gives something for the bench vise to hold on to. The spine is fastened 2 inches back from the edge to allow room to set clamps.
The small bit of darker wood at rear is a spacer the same width of the inside vise jaw so the board bears directly on the edge of the bench, which helps keep the far end from wiggling.
Bottom of the Sled
Since I made the planing board, several improvements have been implemented. The first was, I drilled a bunch more peg holes, and cut a handful of 3/4″ pegs in various lengths to fit the job. This photo shows the bottom of the board.
Planing Board Bottom
Each added hole has a slot routed in the bottom to accommodate a steel pin screwed into these short pegs. The pin helps keep the peg from wobbling in the relatively thin plywood. For most jobs though, it is sufficient to insert a peg in the top of the board. Note I have planed a flat spot in the side of each peg and the steel pins align the flat.
Planing along a board edge was a problem because the larger cam sticks out far enough and high enough to interfere with the tool. I can raise a work piece by putting spacers underneath, but my Stanley 45 fence hit the protruding cam. The solution was to provide a long, thin spacer between the cam and the work. This is made of a half thickness of maple flooring, with a milled slot that accepts a carriage bolt. I loosely fit the bolt through one of the spine holes and it keeps the spacer from buckling. Planes now have plenty of clearance.
Spacer in Use
This photo shows a work piece locked in by the large cam using the hardwood spacer.
The Cam Spacer
A close view of the spacer. The slot is wide enough for the carriage bolt head but has a narrower bottom so the bolt won’t spin when tightening the wing nut.
In the four years since it was constructed, I have used this planing board a lot. I consider it one of my more successful projects. Nowhere was it used more than the Eleven Grooved Box project. Every piece goes on the board for smoothing and grooving.
This photo shows stock for the box sides getting the last of three grooves. The Stanley 45 has to reference it’s fence against the vertical edge of the work which I have aligned with the edge of the planing board. You can see how the long spacer block just behind my left hand keeps the cam far enough behind the plane fence that they don’t interfere.
Here, the thin board which forms the top or bottom of an Eleven Grooved Box is getting rabbited so it fits into it’s eighth inch groove. I could not do this operation without clamping in the planing board. Again, using the spacer block so the cam doesn’t interfere with the fillister plane.
Rabbit end grain edges to 1/8 inch
Finally, this is an interesting use of the board. The edges of the thin Eleven Grooved Box lip strip have to be planed down until the strip fits tightly in it’s groove. I stick several pegs in the planing board and weave the strip through them. The strip stays put and planing the edge square is easy with a big Stanley number six. It’s very quick to pop out the strip to test it’s fit.
Preparing to trim lip strip