It is possible to set up a slackline anywhere you want. An important tool for setting up the perfect line anywhere is the A-frame. The A-frame is a simple wood construction that you can use to set the end of your line at the height and length you want. The line passes over the A-frame (and anchors to it) and goes to whatever anchor you may have. If you're having troubles finding anchors click here. Tools you'll need to build the A-frame include a circular saw (a jig/sabre saw will do), a drill, and a 1.5-inch hole saw/spade drill bit. you'll also need lumber, screws, and wood glue. **Be sure to use safety glasses when using power tools.** You'll also need a 3/8" high strength chain link of approximately 5000 pound working load. You can find this chain at Home Depot in most cities. Buy 1 foot of the chain and cut every other link with a hack saw to free the others. You can also use a high strength 2" rap ring with a breaking strength of no less than 50kN.
Here's how to build the A-frame:
Step 1: Cut 2 pieces of wood with a 60 degree angle on one end and a 30 degree on the other. These will be the legs. Use 2X4s if your A-frame will be taller than 30-inches (or if you want a beefy A-frame), 2X3s if it'll be 30 inches tall or less. The length of the legs is determined by the following equation: L = (height + 2.625) * 1.155. Examples: for a 28" cut them at 35-3/8", for 32" use 40", for 36" use 44-9/16", and for 40" use 49-1/4". This is the length of the long side.
Step 2a: Cut the end of the sharper end 2-5/8" down from the end (on the edge you cut) at a right angle (90 degrees).
Step 2b: Repeat for the other piece of wood and place the two pieces together as shown. If you did it right the width of the legs should be about the same as the length you originally cut the wood to i.e. for a 28-inch A-frame the base width would be about 35-3/8". This wide base keeps the A-frame stable even when doing tricks and falling off.
Step 3:
Keeping the legs in the same orientation place them on a piece of 3/8" plywood that is already cut to a width of half the A-frames height i.e. 14 inches for a 28-inch tall A-frame. This dimension is vertical in the picture shown. Trace the outside two edges and cut them with a circular saw.
Step 4: Wood glue and screw the plywood to the legs. Make sure to use enough glue that it seeps out the edges a little. Clean up the excess with a wet rag. Use a screw pattern similar to the one shown. Repeat for the other side. Don't use the A-frame until the glue is dried.
Step 5a: From the middle of the top measure down 2-5/8" for your hole.
Step 5b: Drill through the A-frame with your 1-1/2" hole saw/spade drill bit. The hole saw will cut better than a spade bit, which will make a rough hole. With the hole saw you may have to clean the pieces out as you cut through them.
Step 6: Sand all edges with 120 grit sandpaper doing a really good job on the edges of the hole and the top. These parts will contact the slackline and should be well rounded. When the line is tightened for the first time it will sink into the wood a little and more sanding may be required. Now you're ready to set up the slackline.
Step 7: Setting Up
For the sake of ease we'll assume that one end of the line is already anchored to a tree and your other anchor (after the A-frame) will be at ground level (i.e. pallets, a car/truck's wheels, stakes, the base of a tree etc.). Begin by threading the line through the chain link or rap ring and then through the hole in the A-frame..
Step 8: Bring the line back over the A-frame and back through the chain link/rap ring.
Step 9: Tighten up the line around the A-frame where you want it to sit and tie it to your tightening system (not shown in picture). The tightening system is then attached to the anchor. The chain link/rap ring should sit flat on top of the A-frame before tightening. Now you're ready to tighten. As you tighten and the line stretches you'll have to move the A-frame so that it stays vertical.
*Be careful when surfing the line since it is possible for A-frames to tip or slide. Look for a coming Tip of the Month on how to surf-proof your A-frame.
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