Orthographic Projection (Cylindrical)

Toolbar / Icon:
Add-on:  QCAD Pro Tools
Menu: Modify - Orthographic Projection (Cylindrical)
Shortcut: P, R
Commands: orthocylindrical | orthocyl | pr


Creates an orthographic projection of the selected entities onto a cylindric surface. This is typically used to create the edge of a drilling in a side view of a cylinder as shown in the figure below on the right.


  1. Select the entities you want to project. In the example below, that is the circle at the left.
  2. Start this tool.
  3. Click the start point of the unprojected cylinder axis. In the example below that is at the top center of the cylinder at the left.
  4. Click the end point of the cylinder axis.
  5. Click the reference point. The reference point in the selection will be used to place the projected entities into the side view.
  6. Adjust the parameters in the options tool bar as desired.
    The cylinder diameter is the diameter of the cylindric shape we are projecting onto.
    The cylinder rotation is the rotation of the projected entities around the cylinder axis. Typically 90 or -90 degrees.
    Since the resulting shapes are likely neither lines or arcs, projected entities are split up into polylines with small segments. You can adjust the segment length used in the options tool bar.
    The clipping option can be enabled to automatically hide the part of the projected shape that would lay behind the X/Y plane.
  7. Click the target point to position the projection.