Introduction: Dual Crosscut Sled From Scrap
This is an instructable for a simple cross cut sled, to be used with a table saw. Crosscut sleds are used to guide pieces of wood, small panels etc. accurately across the table of the saw. This one is reversible, and can be used for cutting straight across (90') or for doing mitre/bevels at (45') by turning it round.
And best of all, it's made from scrap.
Step 1: Motivation, Parts List ...
Tablesaws are great at "ripping" (longitudinal sawing) and mitreing, and the built in fences and guides are optimised for that.
Crosscutting is possible, but needs a better guide for the work to keep it straight. A sled is useful because it helps keep your fingers well away from the blade -- always a good thing on table saws.
My table saw is a fairly cheap model, so it came with a tiny crosscut/mitreing fence, which is okay for some jobs, but not larger pieces, or cutting multiple small pieces at once.
This was originally inspired by a project in a Woodworking magazine.
- The original saw used had two guide slots, left and right of the blade (so the sled could be moved left to right to change which slot to use)
- The original saw had no (or a removable) splitter/riving knife fitted.
- It was made with love and care from proper wood.
- My saw has a single guide slot across the table, to the left of the blade.
- And what looks like a fairly non negotiable riving knife.
- And recycling junk into useful jigs is fun.
Sizes are not critical and can be adapted as needed. With these sizes, the sled can cut up to 9" width at one go.
- Wood "fences" (must be straight, 15mm x 50mm x 450-520mm) (2)
- Plywood sheet (6mm thick, approx 550mmx270mm) (1)
- Wooden stick (to fit table slot x 300mm long) (1)
- No 4 countersunk wood screws (1/2") (4)
- No 8 countersunk wood screws (1") (14)
You need a wooden stick that closely fits the guide slot in the table saw. In my case, 12mm wide by 10mm deep. I found a trimmed piece of 12mm pine which was coincidentally EXACTLY the right depth for the job. A little shallower than the slot is ok, standing proud is NOT ok. It needs to be a close fit side-to-side, otherwise the sled will wobble!
Mark the centre line of the stick, at both ends, to aid lining up later.
Step 2: Sled Guide Stick
I used two pieces of plywood here, because together they were big enough. You can use a single piece if you have one. They don't need to be perfectly square, I rough cut the edges by hand.
Strike a line across the board at as near as 90 degrees as you can. This line will be where the stick is mounted, and will become the reference for all the other parts. The line is about at the centre of the board, and means that when slid toward the saw, there will be a couple of inches "beyond" the blade, no matter which way the sled faces.
This dictates the minimum size of board you can use, it must be a bit more than twice the distance from the slot to the blade.
Clamp the stick underneath, and then attach it. I pre-drilled four clearance holes in the plywood, and countersunk them. Then pilot drill into the stick. The screw heads MUST be sunk just into the ply. You can see the alignment is correct when the line down the centre of the stick matches your 90 degree line across the board. At both ends!
Remove the clamps.
Step 3: Add Two Fences
Take one of the fences and attach it to the top surface of the board(s). This piece MUST be at 90 degrees to the line you marked, otherwise the sled will cut funny angles!
For the "90 degree cut" side of the sled, the fence needs to overlap the place where the blade will cut through. By at least an inch or two. On both sides of the board! Otherwise there will be nothing to hold the boards together and part of the sled will fall off.
Although in my second image above you may notice it is actually short at the rear-right. More on this later!
Fit the sled on the table saw and mark where the centre line of the blade will hit, from the front and back.
Plan where the screws are going to go! You need one screw either side of where the blade will pass through, to hold the boards together.
Leave at least half an inch from the face of the blade. Check BOTH SIDES (front and back fence) that the blade is not going to hit one of the screws -- remember, this thing will be turned round, AND the blade will pass through both sides, so there are four "danger zones" for screws. Make sure you find them all at THIS point, not with the blade :(
Again I pre-drilled and countersunk some holes in the plywood, and started by screwing one in near the centre, adjusting the fence (by waggling it) until it was square -- use the largest square you can fit onto the sled -- then clamping the fence in place before piloting and screwing the rest.
Repeat for the second fence. This one is for the 45 degree side, and doesn't need to hold the board together -- in fact, part of the board will be cut off the first time it's used. Leave much more space allowance for screws around the blade -- when it leans over it will reach further -- see the final picture at the end.
Step 4: Riving Knife/Splitter Clearance
Naturally I had to remove the protective plastic guard over the blade, as is often the case with cutting taller items. But then there's one more obstacle.
This is why the 90 degree fence looks short. On my table, there is a "riving knife" which prevents work from catching on the blade and being thrown upward. However, it also stops the wooden fence -- which is only SLOTTED, and not cut THROUGH -- from passing over the blade, as the knife is taller than the blade's cutting path.
So I made a separate small block, with an enthusiastic clearance (width AND height) to allow the blade and knife through. This block is screwed either side of the location of the blade, the same way the main fences were.
So: check that the blade is 90 degrees to the table. Don't just read it off the adjustment dial -- they can be a degree or two off.
Do this with a square up pressed up against the stationary blade, and the blade as high as you can set it. Adjust the angle of the blade so there is no daylight peeping through between the square and the blade. Lock the angle, then lower the blade so that it will cut through the plywood, but not much more.
One last check: There must be no screws directly in the path of the blade. There should be a screw either side of the blade to keep it together!
When you first attempt to push the sled through, the blade will cut a starter notch in the plywood, as shown, and in the block, then come to a halt because of the knife. Stop cutting.
Unscrew the block and widen/deepen the slot with something OTHER THAN the table saw, for safety!. Screw it back in place.
Step 5: Complete the Cross Cut Slot
You should be able to continue the cut right the way across the sled.
The riving knife will probably stop you a second time (on the front fence), but this is okay as by now you would have cut through the real "work".
That's the 90 degree side done.
Step 6: Add the Bevel Cut Slot
Time to do the other side.
Lean the blade over to 45 degrees: Again use a 45-45-90 square with the blade as high as you can set it, check for no visible gaps, lock it, then lower it to a safer level.
Turn the sled round. This time, you won't have a back fence to clear, and part of the plywood will be sawn off. This is normal. You should end up with a 45 degree slot in the front fence.
Before cutting, check once more where the screws are and visualise where the blade will cut.
Then push the whole sled through and saw off the base board and make that notch!
Step 7: Done!
The end result should look like this. Maybe even neater :)
To use the sled, make sure it's facing the right way (!), set the saw blade to exactly 90 or 45 degrees, and keep the work clamped firmly against whichever fence is at the "front" of the sled (towards you). The sled can only go dead straight across. Keep it held firmly down to the table, and glide it across.
The exact line the blade will cut lines up with the slot in the front fence (and the base board), hopefully no surprises there!
You can clamp a small wooden block to the front fence to act as a stop, for making repeated identical cuts. Press the work up against the fence, slide it along till it hits the stop block, and cut!
Note in the last picture above, I added a marker for the rightmost screw on the 45' side. This is just beyond the reach of the blade, but it's there as a reminder not to saw through it!
You may need to occasionally put a small amount of wax/polish/WD40 etc onto the guide stick to get it running freely, if it's a tight fit.