From the technical point of view, creation of the drawing and the subsequent construction of ladder is quite feasible task. However, it is necessary to consider that the design of ladder has to meet construction standards. And its operation to be safe and comfortable. At design of ladder it is very easy to make mistake. Therefore it is necessary to make the detailed project and the exact drawing of ladder design.
- - pencil;
- - eraser;
- - ruler;
- - protractor;
- - compasses;
- - paper;
- - tape measure
1. Choose drawing scale.
2. Measure the sizes of walls and apply them on paper. Draw wall bowstring. Make the correction on plaster layer of each wall. Leave gap between notch board and wall. The size of gap has to be 20 mm.
3. Draw external bowstring.
4. Apply bisecting line of stair flight on the drawing. This line has to pass between two notch boards and come to an end at the level of vekhny step. The provision of the top step is defined proceeding from building constructions of the room.
5. Define the provision of other steps of ladder being guided by the provision of its top step. Note depth of insert of steps on bowstrings. As a rule, this depth is 15-20 cm.
6. Determine height of ladder steps. For this purpose separate building floor height into quantity of steps. On bisecting line of stair flight of step have to have identical width.
7. Apply the final width of treads on the drawing. At straight staircases of tread pass in parallel each other and have identical width.
8. By drawing up the drawing of ladder with turn by 90 or 180 degrees it is necessary to construct vertical and horizontal development. Apply the pieces equal to width of steps, on bisecting line of horizontal projection of ladder. Define extreme direct steps. Construct vertical development of ladder on contour of internal bowstring. "Unroll" the line of horizontal projection of contour of internal notch board across. Note down height of steps. Connect borders of the curvilinear site direct piece. Carry out from initial and final points of this piece of the line, perpendicular to edges of direct steps. Find the middle of this piece. Construct the perpendicular lines passing through the center of each of two turned-out pieces. Note points on crossing of two perpendiculars. Draw two circles with the center in these points and the radius equal to length of the piece connecting edges of direct steps to the ends of the curvilinear site. These circles will give you the exact line of development.
9. Apply the sizes of steps of ladder on upright projection. Steps have to have the wedge-shaped form. Steps on average flight of stairs have to have identical width.
10. Take two rectangular pieces of cardboard with width equal to height of the stair riser. Apply on them width of wedge-shaped steps, according to horizontal projection. Mark notch boards on these templates. The drawing of ladder is ready.