For such a ladder, two 60×40 mm beams will be required, which will go to two bowstrings. Choose the length for yourself, in this case it is 3.6 m. A smaller bar will go to the crossbeams – 50×35 mm. To determine the number of steps, divide the length of the ladder into sections equal to the height from the floor to the foot when the leg is bent at the knee. In the above version, these are 11 steps every 30 cm.
For work, you will need a hacksaw, a hammer, a pry bar, a small hatchet – preferably a carpenter’s one, with a butt in the form of a hammer. From the power tool – a drill, a belt grinder, a plane and a jigsaw (instead of a hacksaw). You can use nails as the main fasteners, but self-tapping screws will be more reliable. Black hardened is not suitable, they can burst under load, so buy ordinary steel with anodized coating and a head with a sweep.
To make the ladder more durable, and the upper edge of the step when tilting – horizontal, on the short edge of the bowstring you need to make notches. First, mark the marks along the length of the bar at the places where the steps are installed, step back from them the width of the crossbars – 50 mm, and apply a second mark by drawing the edges of the notches under the square. Transfer the marks to the side edges on both sides, mark the depth of the notch at the bottom – 15–20 mm, and make a cut to this depth. Connect the labels together with a slash.
Place the hatchet with the tip on the top mark and, tapping on the butt with a hammer, chop off the wood.
Using the ax as a plane, trim the resulting notch bevel.
Make notches on both strings to speed up the process – knock them together with nails.
Bars on bowstrings need to be lightened a little by processing the edges with a grinder.
Pay special attention to the notches, carefully sand the bevel.
Paint the inside of the notches and set them aside for a while..
Then there are the steps. First, work a little with a plane to remove such a neat chamfer on each bar:
For further work with the steps, you will need to make one end of the base. Draw square marks on one of the ends.
Saw off the uneven edges and process the butt end with a grinder, for beauty, you can remove a small chamfer. Similar to the bowstrings, lighten the wood a little and make the surface smooth..
Now you need to make the top and bottom crossbars. To visually quickly distinguish the top and bottom of the stairs, it is made with a slight taper, so the top bar is slightly shorter than the bottom. Choose the width of the stairs that is convenient, in the given version it is 65 cm at the bottom and 55 cm at the top. Mark the length using a tape measure.
And draw a cut line in a square.
Cut off excess bar.
And grind the ends.
Draw a line under a square, stepping back from each edge by half the thickness of the bowstring – 20 mm. Mark the center of this line, you get the following markup:
Drill a through hole on the crosshair so that the self-tapping thread passes through it freely.
Make a small countersink with a larger drill.
Place the top and bottom rungs in the notches and align the ladder so that the ends of the steps are flush with the side edges of the bowstrings..
Measure the diameter of the thread shank and choose a drill 0.2–0.3 mm smaller. In this case, the rod diameter was 2.8 mm, so a 2.5 mm drill was installed in the drill..
Mark the notch bevel through the hole in the steps, maintaining the position and direction of the drill. Then remove the crossbars and drill a hole 2/3 deep. It is necessary to drill holes for the self-tapping screw so that it does not split the tree, otherwise all the work is down the drain.
Paint the edges of the steps on the back where they abut the string. Then return the steps to their place and tighten the screws.
Now the staircase has the required dimensions, it remains only to fasten the missing steps. Place the sticks in the notches and align the base ends flush with the side edges of the bowstrings.
Mark on the crossbars the desired length along the opposite bowstring.
Prepare and install the steps as the first two: draw cutting lines under a square, cut off the excess and grind the ends with a grinder. Mark the edges for drilling and make countersink holes. Then tint the edges and install the steps in place, pre-drilling the string with a small drill.
It’s time to paint. There are no special secrets here, but if you want the paint not to clog the slots in the head, unscrew the screws 3-4 turns and tighten them after painting.
If, after painting, a tree is visible in some places, you need to apply a second layer. Alkyd paint fully cures in 30 hours, after which the ladder can be used.