Make a Children’s Sleigh
Outdoor Project: Rather than spend another Canadian winter waiting for spring, get outside, enjoy the snow and pretend you’re a kid again!
To make the two bent-laminated, curved runners, you first need to make a form. Essentially, you must remove material the same thickness as the finished runner to form a cavity that the lamination strips will be glued-up in.
Start with a piece of 3/4″ plywood at least 48″ x 20″. Make sure the sides are parallel and the corners are square. With a pencil, straight-edge and trammel heads lay out the curved rail. Make sure you lay out the shape so there’s enough material to play with. When in doubt, make the form larger than you will need. Mark the quadrants of the arc, where the curved section joins the straight section. This line will guide you when routing the arc.
Attach a router to a circle-cutting jig the correct radius, then attach the circle jig to the plywood form at the centre of the arc. So you only have to make one series of progressively deeper passes with the router, install a bit the same diameter as the rail is thick – 1-1/4″. Make a series of shallow passes, stopping at the quadrants with each pass, to rout almost all the way through the 1/4″ plywood. Leave at least 1/8″ of material for now.
To cut the two straight sections of the form, measure from the edge of the plywood to the furthest edge of the routed groove (right at one of the quadrants), and set the table saw to cut that exact distance to the outside of the blade. Make the first cut, stopping just before the 1-1/4″ wide routed groove. Re-adjust the fence to make the second cut, flush with the other surface of the routed cut. In the second instance especially, don’t cut too far, or you will cut into the curved edge. Stop short and use a handsaw to finish the cut.
With a jigsaw, separate the two halves, then flush trim the curved section with router. Cut additional pieces of 3/4″ plywood that can be glued and screwed to both faces of the form halves, increasing the thickness of the form to 2-1/4″. Bandsaw the waste nearly flush with the main, center piece of 3/4″ ply, then trim everything flush with a router and flush trim bit.
Rather than leave the two form halves large and cumbersome, mark a line about 5″ away from the edge of the male form, and about 2-1/2″ away on the female form. The wider section will retain its shape during glue-up, while the thinner section will flex ever so slightly, accounting for any slight variations. To finish the forms, attach a 2″ x 2″ x 5″ long solid block to the end of the female form. This block will help keep the two form halves aligned during glue-up.
To determine how thin to make the strips, I made a few test strips and bent them around the form, checking how hard they were to bend. You want strips that will bend fairly easily, and have no chance of snapping. For the white ash I was using, I settled on 1/8″ thick. Even though the finished strips will be about 48″, make them at least 6″ longer, then cut them to length after they have been laminated. I also cut the strips from the same piece of wide lumber so the grain and colour would match nicely. Once you have broke out enough strips from 8/4 material to make the runners do a dry run of the glue-up. It can be a tricky procedure to align all the strips and have the form come together nicely.
In order to make a good form, you must lay out everything first and work to those lines. Here, Brown measures the distance from the outside of the form to the furthest edge of the routed groove to make the first tablesaw cut.
Unibond 800 allows a long open time, which is great for this tricky glue-up. A dry run will also go a long way to a proper glue-up.
A great way to ensure you have a square, true edge on the runner is to rout one face before removing it from the form (above). Set the bit just below the surface of the plywood base (below) and move the bit over the entire area of the runner.
Rout the Mortises
A plunge router and a mortise jig makes quick work of making a set of mortises, although there are many ways to machine this joint.
After laying out the finger joints and marking the waste portion of the joint, Brown set up a stop block to ease the process. A flat-top blade is great for this job, as it leaves a flat, even upper surface.
Cheap & Simple
In order to hold the workpieces on an angle, make a single-use jig. It’s made with a bottom, face, four angled brackets and two stop blocks that are clamped to the face. It can be screwed to a crosscut sled, and then the workpieces can be clamped to the face and the fingers can be machined in their ends.
With the finger joints on the leg (left) complete, you can use it to measure the finger joints on the cross brace (right). Brown made one pass on the outermost surface of the cross brace, used a handsaw to remove most of the waste, then used his index finger to check the joints against each other.
With both halves of the finger joint cut, you can fine-tune the fit with a shoulder plane and chisel.
Small But Strong
The thing that makes this joint strong is the large amount of face grain surface area for gluing. Apply the glue, bring the joint together by hand and clamp across the joint.
Transfer the Angle
With the runners and leg assemblies together, sit the outside slat on the sleigh, overlapping the edge by 1/2". Slide it up the runner and mark where the slat needs to be cut. A screw will be installed through the slat, into the runner, for extra strength.
Add Two Arcs
Strictly for aesthetic purposes, arcs should be cut on both ends of the slats. With the slats temporarily attached use a beam and trammel points to draw two arcs, then trim the parts with a bandsaw.
Trim the Runners
Place a piece of 1/2" thick plywood on top of the outside slats and cut the runners flush with its top surface. Ease all the corners at the end of the runner, mainly for safety reasons.
I choose Unibond 800 (vacupress.com) as an adhesive because it’s waterproof, produces a very rigid glue line and has a long open time. The resin and hardener must be mixed together before starting. It takes 24 hours to dry, but with only two runners to make that didn’t pose any problems. Apply the adhesive (I used a cheap 2″ paint brush) to both surfaces of the strips, get them into the form and add clamps.
After 24 hours, the adhesive was rock hard. Rather than removing the lamination from the forms, then truing and planing it, I flattened one surface while it was still clamped in the form. This made it easier to obtain a 90º edge that was straight and true. I took some of the clamps off to make accessing the workpiece possible. After setting up a router with a straight bit I added a partial base to the bottom of the router that would run on the wider, male portion of the form. I adjusted the height of the base so the bit protruded below the base by about 1/8″, then made multiple passes, truing up one side of the work piece.
Add a pencil line where the curved section starts so you can accurately orient the runners down the road. Once out of the form you can trim any ragged ends off, if necessary. Just be sure to not remove too much length. The runner can now be planed to a final width of 1-5/8″. Repeat the glue-up for the other runner.
Four mortises and tenons
I used a shop-made mortising jig to cut two mortises in each runner, but whatever method you want to use is fine. My jig is clamped in my bench vise, and the runner is in turn clamped to the jig. A template guide attached to my router base runs in a groove in the jig, which in turn guides my router. I machined a 1/2″ mortise that was 1-7/8″ long and 1/4″ less than the thickness of the runner. Although not critical, the front mortises were cut about 7″ behind the quadrant pencil line, and the two mortises were 17″ apart, on center. The final step was to cut the tail end of the runners to length, at a 10º angle.
Set the runners aside for now, and break out the four legs and two cross braces. An extra leg and cross brace isn’t a bad idea, as angles have a way of confusing the situation. I then used a tablesaw and tenoning jig to cut the tenons on the end of each leg, fitted each tenon to a specific mortise and numbered each joint so they could all mate-up back together. Next, cut the legs to final length with a 10º angle on each end.
A special finger joint jig
To ensure a strong joint between the legs and cross braces, I decided on a joint with lots of face grain glue area; a finger joint. This would normally be an easy joint to machine, but the 10-1/4 angle made things more complex. The solution to this problem was a jig that would hold the parts 10-1/4 off perpendicular while they were being machined on the table saw. I assembled the particle board jig and made two particle board stops that could be clamped to the jigs’ face to increase productivity and accuracy. I attached this jig to the surface of my cross-cut sled, perpendicular to the blade. I figured three ‘fingers’ on each leg, that would mate with two ‘fingers’ on the end of the cross members, would be enough surface area to hold solid. After laying out the joint, and marking the waste for clarity, I proceeded to cut the joints in the legs using the stops. I also made sure I used a flat top blade to produce a nice, even joint.
Once the leg portion of the finger joints were cut, I cut the cross members to length, with the same 10º angle on both of their ends. I numbered the four joints then transferred the location of the joint from the leg ‘fingers’, and reset the stop block. I started with the outside two surfaces, and made sure they were the correct width apart, or just a hair too wide. Checking against the appropriate leg joint gave me accurate measurements. These two surfaces would be easy to trim later with a shoulder plane to get a perfect fit.
When I was satisfied with the outer faces of the cross-brace I set the stops to remove the material between the two fingers. I set it up a little conservatively, not wanting to remove too much material. After a few test passes, I made the final cuts on the cross-braces. I then fine-tuned each joint to make sure each was as strong as could be.
Glue things up
With the legs and cross braces ready, I sanded all the exposed surfaces and prepared for the glue-up. Again, I used Unibond 800 for this assembly. Covering all the fingers with adhesive and bringing the joints together, I clamped across the fingers and left it to dry. I found an interesting quality in this adhesive while using it. PVA glues cause the wood fibres to swell slightly, increasing friction during assembly, but Unibond 800 acted more like a lubricant, allowing the joint to come together a little bit easier.
When the adhesive was dry I flushed up the joint. Because comfort was important I opted for 1/4″ roundover bit in my router to ease all the edges of the legs and cross-braces. At this point, I was ready to join the leg assemblies to the runners, so I mixed up more adhesive, applied it to the joints and brought everything together at the same time.
Start the seat
Break out the two outside seat slats to a rough size of 41″ long and 3-1/2″ wide. Place them on the assembly, overhanging the legs by about 1/2″, and butting up to the front of the runners. Because the runners are on a 10-1/4 angle the outside slats will have to be angled on their outside edge to mate properly. Mark the angle and location on the front of the slats and use a handsaw, or a bandsaw with its table angled, to trim the slat. This angled surface with have to be faired with the rest of the edge with a spokeshave. Bandsawing the rest of the slat to shape is more about aesthetics than anything. Just be sure not to narrow the front of the outside slats as to overly weaken them. Though the backs of the slats are not cut to final shape, temporarily screw them in place while fitting the three middle slats.
The middle seat slats can now be machined, and temporarily screwed in place with even gaps between each slat. The finished length of each slat is about 24″, but keeping them longer for now will allow for more flexibility when laying out their final shape.
Add some curves
With a piece of scrap clamped between the outer slats to give you a center point to use your trammel heads, draw an arc on the tail ends of all the slats and the front end of the middle seat slats. As long as there is some overhang from the two cross-braces, your main concern when drawing the arcs is how the sleigh will look. Remove the slats and bandsaw them to final shape. After rounding over the edges and sanding all the surfaces, reinstall the slats with glue and screws. Don’t forget to add glue and a screw to the front of the outside slats, to fix them to the front of the runner. Plug the screw holes in the slats.
Next, cut the front cross rail to size, bandsaw a pleasing shape on it and fit it to join with the outside slats and runners. It might take some shaping to get it to fit nicely. Don’t worry about a perfect fit though. Once ready, install it with glue and screws. This rail helps add rigidity to the sleigh and gives the user a great place to rest their boots while using the sleigh.
It’s finally time to cut the front of the runners to length. With a piece of 1/2″ material on top of the outside slats, flush cut the runners with a handsaw. Shape the area with a file and sandpaper, leaving no sharp corners. Drill two holes in the front cross-rail to accept the rope, and counter sink its edges so it doesn’t wear the rope. Insert each end of an 8′ length of 1/4″ rope into a hole and tie simple knots underneath the rail.
Finish the sleigh
I applied three coats of exterior polyurethane to the sleigh, sanding between coats. Don’t worry about the underside of the runners, as the finish will wear off very quickly. I think the best finish for that area is a light coat of paste wax, so the sleigh will be easier to pull across the snow and will go faster down the hills.
Now that you’ve had your fun making this sleigh, grab your kids or grandchildren and head to the hills. This might be the most fun you’ve ever had while using one of your projects.