Introduction: Scroll Saw Crosscut Sled
A scroll saw is the perfect tool for cutting intricate shapes and tight curves, but I need a perfect right angle cut sometimes, so I devised a sled like I use on my table saw . . . only much smaller.
The sled not only guarantees a perfect 90 degree cut each time, it is a much safer way to cut very small pieces and it allows use of hold downs. It also permits use of a stop block to allow uniform multiple cuts.
Adding a v-notch helps hold round stock such as dowel and tubes for clean, safe cuts.
The entire project can be made with wood from your scrap bin and constructed with basic tools. The finished sled is held in place on the scroll saw table with simple clamps.
Step 1: Materials
You will need
a few small pieces of wood
small nails or screws
optional: carpenter's yellow glue
optional: pin nailer (air or electric)
optional: table saw
optional: carpenter's square
Oh yes, you'll need a scroll saw
Your scrap bin will most likely yield all the wood you need for this project. I listed some optional items that made this project easy - a power nailer speeds assembly. (I routinely "glue-and-screw" all my joints, but that is not really critical on something like this). A table saw helps cut pieces straight and true, but all this can be done with hand tools. A router (I used a router table) helps cut the channels that the tracks ride in - which can be done with a hand chisel if you are very precise and have fathomless patience.
A block of wood that you know to be perfectly square can be used to position the parts, but a carpenter's square is definitely 'dead-on' 90 degrees.
Step 2: Cut the Pieces
The sled consists of a lower piece and an upper piece with a narrow piece (fence) on top. The lower piece is sized to fit your scroll saw to allow enough to be clamped to the saw table while extending deep enough to reach the blade (mine is a piece of 3/4" pine measuring 9" x 11".)
The upper piece is another piece of 3/4" pine measuring 5 1/2" x 7 1/2" - the measurements are not important but should be cut to best fit your scroll saw.
Along the full width of the upper piece is the fence - a narrow piece of wood that stock is held against when making cuts. My fence is 1/2" thick, 3/4" wide, and 7 1/2" long. It is recommended that the fence is square to the sled for accurate cuts . . . method for squaring it and attaching it are given in Step 6 below.
You will need enough runner material (mine are 1/4" x 3/8".) The runners I used were made 11" long, which I cut in two to make each runner about 5 1/2" in length - a tiny bit long on purpose. It is easier to trim to the exact size you want if you go a little long. The runner material should fit snugly into the two channels that are cut into the lower piece. It is better to err on the side of too big than too small at this step - a too-tight piece can be sanded and tried over and over until a proper fit is achieved: slides easily without too much wiggle in the slot.
They call this trial-and-error fitting process "sneaking up" on a good fit.
The sled has two runners underneath the upper piece that fit into dado slots (channels) that run the short length of the lower piece; the runners (mine are 1/4" x 3/8" and 5 1/2" long) fit into slots I cut into the lower piece that are 1/4" wide and 1/2" deep.
Step 3: Cut Slots
Come in about 2 1/2" in from each short side of the lower piece and cut a slot (dado) from edge-to-edge; the slots on my sled are 9" long, 1/4" wide, and 1/2" deep.
A router makes this step much easier. A router table made the job even easier. Without a router, these slots can be carved with a handheld chisel. Make sure you have very accurate layout lines, a razor-sharp chisel, and make perfect cuts if you try this without a router.
Step 4: Install Runners
Place the two runners into the two slots. The runners should be snug in the slots but slide easily. Let the runners extend a quarter inch or so beyond the ends of the channels in the upper piece - you can trim the excess later. The runners should be snug in the slots but slide easily.
Line some toothpicks end to end in the slots before installing the runners - the idea is to make the runners show slightly above the face of the lower piece (very slightly or what woodworkers call "proud" - maybe just 1/64" is all you need.) By leaving the runners "bumped up just a hair," you can carefully paint just the top of each runner with a light coat of glue.
With glue applied to each runner, carefully put the upper piece in place and let the glue dry (give it at least two hours - overnight is better. When putting the upper piece in place on the glued runners, make an effort to get it "square." This is best accomplished with a carpenter's square (or a piece of wood that you know to be perfectly 90 degrees on each corner.
Once the glue is dry, get rid of those toothpicks and lay the upper piece onto the lower piece (the toothpicks will leave a gap between the runner and the bottom of the slots to allow better sliding. By gluing and then tacking with a pin nailer or driving screws, you don't have to clamp anything in place or wait for it to dry.
Once completely dry, rub one or more coats of paste wax to the runner sides and the whole underneath of the upper piece to further aid sliding freely.
Step 5: Assemble Pieces
As you add the upper piece, make sure it is squared up as best you can - the more accurate you are in this step, the better 90 degree cuts you'll make.
The finished sled consists of a lower piece with two slots and an upper piece with two runners. The upper piece also has an optional v notch and a fence (not optional) running the full width of the piece.
The fence is secured as a last step to make sure the fence and saw blade are positioned at 90 degrees.
Step 6: Square the Fence
Once the completed sled is assembled, at the center of the lower piece, make a cut from the edge all the way to the fence. This will show exactly where the cut will be made so you can line up your reference mark for the cut. This cut line will allow you to square the fence to the sled.
To install the fence onto the upper piece, line the fence up along the v-notch and secure only one end of the fence with a nail or screw. Using a square, put the fence at 90 degrees to the cut you made. Once it is perfectly square, secure the other end of the fence. Now drive a few more nails or additional screws to secure the fence permanently.
Step 7: Using the Sled
Secure the lower piece to the scroll saw table with clamps, making sure the clamps won't interfere with the motion of the sled or the movement of your stock. Small pieces of wood can help level the bottom side as most scroll saw tables are not flat on the bottom side. The little wood blocks often help prevent damage from tightening clamps too hard.
The sled will accommodate round as well as flat stock. With the addition of a stop block, uniform duplicate cuts can be made easily. An example would be cutting 1 1/2" wood dowel into uniform disks of 3/8" thick to be used for wheels for toys. Flat stock can be safely cut into very small pieces by using the sled.
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