Video Transcript
In this QCAD tutorial, we will explore object snaps.
Object snaps help us to precisely align and connect entities in QCAD drawings.
We'll cover auto snap as well as manually snapping to specific points.
Example drawing: autosnap.dxf
To demonstrate the different snap tools, let's look at this example drawing.
We start by drawing a line onto layer Construction.
We set the startpoint of the line somewhere on the left on a grid point as we did in previous tutorials.
The grid snap allows us to position the start point of the line at the exact location of a grid point.
However, in most CAD drawings, many things do not align with the grid.
We need to be able to use intersection points or connect lines to endpoints and so on.
This is what object snaps are used for.
We can find the most common snap points by simply moving the mouse cursor close to the desired location.
For example, if we move the mouse close to the intersection of the two red center lines, QCAD automatically snaps to the intersection point of the two lines.
Note that we do not have to position the mouse cursor at exactly the intersection point, just close enough for QCAD to know that we want to use that point.
QCAD automatically computes the closest intersection point and tells us that it is snapping to an intersection.
The position QCAD is working with right now, is the exact intersection point of these two lines.
The large yellow crosshairs indicate the position QCAD is using.
These yellow crosshairs are usually relatively close to the mouse pointer, but they can also be further away as we will see later on.
Clicking the left mouse button at this point would draw a line to the intersection point of the two red lines.
But let's explore some other auto snap points.
Here, we find another intersection point. This time between the arc and the red line.
We can also snap to tangent points while drawing lines.
The middle point of the arc is another auto snap point.
The perpendicular point is the point where the line meets the arc at a right angle.
These are the most commonly used object snaps that are covered by auto snap.
Auto snap is the default snap mode of QCAD.
It simply means that QCAD automatically snaps to the closest, meaningful reference point.
Auto snap is sufficient for most situations.
However, object snaps don't stop here.
We can also tell QCAD to only snap to specific types of points, for example only to endpoints.
This can be especially useful if there are many different reference points in a small area.
For example, we have here an intersection point and very close by to the right an endpoint.
Although not impossible, it can be a bit tricky to snap to the endpoint of the thin line using auto snap.
Instead, we activate the end snap in the CAD toolbar at the left.
If we now move the mouse cursor around in our drawing, we find that QCAD only snaps to endpoints, even if the mouse cursor is closer to an intersection point.
We can also move the mouse cursor much further away from an endpoint and still snap to that endpoint.
This allows us to easily snap to the desired endpoint of the thin line.
In the same way, we can also activate the other auto snap modes individually by clicking their corresponding buttons in the snap toolbar.
Another useful snap mode is the center snap mode.
It allows us to snap to the center points of arcs, circles and ellipses by clicking on the corresponding entity rather than the center point itself.
Let's look at another specialized snap mode.
Example drawing: intersection_manual.dxf
This snap mode allows us to snap to the point where two entities would intersect if they would be longer.
We demonstrate this snap mode with the line tool.
This snap mode is called "intersection manual".
In this mode, we can manually choose two entities to find the intersection point.
For this example, we click the horizontal center line as our first entity to define the intersection point.
For the second entity, we move over to the view at the right.
This way, we can snap to the point where the horizontal center line would intersect the arc in the side view.
We set the start point of our line at this imaginary intersection point.
For the endpoint we choose the same snap mode again to find the intersection at the other edge of the side view.
A similar snap tool allows us to snap to the middle between two points.
Consider this example drawing with a text label and a rectangular shape.
Example drawing: middle_manual.dxf
We want to move the text label in this drawing exactly to the center of the rectangle.
First, we select the text and cut it to the clipboard using the cut tool.
For the reference point, we choose the reference point of the text at its center.
The text entity is now on the clipboard.
When we paste the clipboard, we can position the text using the chosen reference point.
To find the exact center of the rectangular shape, we can use the snap mode called "middle manual".
We activate the snap mode and then click the two middle points at the top and bottom of the rectangle to find the center point of the rectangle.
The last snap mode we are going to demonstrate in this tutorial is to snap to points with a given distance to an endpoint.
Example drawing: distance2.dxf
In this drawing, we want to construct the dashed line here already indicated in red.
We know the distance of the endpoints from the lower edge on each side of the rectangle as indicated by the dimensions.
Example drawing: distance.dxf
This snap mode is called "distance snap".
We can enter the desired distance from the endpoint in the options toolbar at the top.
For this example, we enter 12.5 for our first distance.
We can now snap to points with this distance from an endpoint by simply moving the mouse cursor to the approximate location.
Note that there's also another point on that entity we can snap to.
This snap point is 12.5 units away from the top edge.
We can now simply click the start point of the line at the desired snap point.
For the endpoint, we enter the distance along the right side.
We click a point close to the desired snap point to set the endpoint of the line.
You should now understand the basics of object snaps.
Be sure to practice this with your own installation.
Thank you for watching this QCAD tutorial.