Callouts for Holes in Mechanical Drawing

[Chips&Chips]

A very common element in mechanical drawings is a callout for the details of finishing a hole. The general way of doing this is shown here:

https://rathasochenda.com/wp-content/up ... llouts.pdf

A Leader that points to the center of the hole/circle with an arrowhead that terminates on the outside diameter of that hole/circle connects it to the descriptive text which is outside of the outline of the part. Here is an example of this in QCAD:

HoleCallout01.jpg (77.9 KiB) Viewed 46373 times

The problem is how to accomplish this in QCAD with as few steps as possible. I tried many methods and almost gave up with a method that required construction lines, layer switching, and which took much longer than doing it in my previous 2D CAD program. The big problem is having the Leader point directly at the center of the circle while touching the outside diameter: this is not trivial. The difficulty was that the Leader tool in the Dimensions menu was the only way of producing a line with an arrowhead while the best way of having the line point directly at the center of the circle was to lay it down to that center point. But then the Leaders produced apparently could not be edited to remove segments as the Break Out Segment tool or the Trim RM tool would do with other types of lines so you are stuck with the arrowhead inside the circle. I was in the process of reporting this as a needed feature when I finally stumbled on a method that worked and worked quickly.

First you do draw the Leader starting at the center of the circle. That guarantees that the line does point there.

HoleCallout02.jpg (94.97 KiB) Viewed 46373 times

Then the Leader is selected and the Stretch tool is used. Include the entire arrowhead in the selection box and use the center of the circle as the Reference Point and the intersection of the Leader and the circle as the Target Point.

HoleCallout03.jpg (153.33 KiB) Viewed 46373 times

HoleCallout04.jpg (51.99 KiB) Viewed 46373 times

And it is done.

HoleCallout05.jpg (93.76 KiB) Viewed 46373 times

Apparently the Leader can be stretched, but not chopped off. I hope this helps some other users/beginners.

Perhaps there is a better way. If so, please share.

[andrew]

Instead of using Modify > Stretch, one can also simply drag the reference point from the center to the circle line:

- Create the leader, pointing the center of the circle
- Select the leader entity
- Move the mouse cursor on top of the reference point at the center of the circle
- Press and hold the left mouse button
- Drag the mouse to the circle line
- Let go of the left mouse button
- Click to place the reference point at the intersection point between the circle line and the previous leader line

[CVH]

Hi,

A solution might be this feature request: FS#2428

When we could draw Leaders the other way around then there is a perpendicular snapping point available on any circle.

Regards,
CVH