Break at Point command and circles

[stephenP66RM]

Is there any way of using the Break at Point command on circles without generating an error?  I have attached a file showing what I am doing, and what I would like to achieve.

The left image shows a circle, and it is partially obscured by a rectangle shape. What I'd like to do is use the break at point command on the circle, using the intersections (indicated by the red circles) as the break points. I select Break at Point, select the circle, select one of the intersection nodes, and then would repeat at the second intersection. The idea is that I end up with two arcs, one of which can be turned into hidden detail (see image on right).

The reality is when I carry out the command, I get an error message saying that the arc cannot be 360 degrees. So, is there a way of doing points at the same time? I'm hoping that there is a quicker way than using the trim command between the horizontal lines, and then redrawing the missing part of the circle using Arc (Centre, Start, End).

Many thanks in advance!

[h_s_walker]

Draw it as a polyline circle. Start the polyline command. Right click select ARC and draw it that way. See the image below. Don't "close" the polyline, just continue with the arc and choose your start point. When you break it will all turn into polyline arcs, but you can JOIN the ones you want back together.

[stephenP66RM]

Thanks for the suggestion, but unfortunately that's not working for me.

I select the polyline icon, right click, and it automatically selects a seemingly arbitrary point as an anchor point. I press the down arrow to choose Arc, at which point the arc is already starting to be drawn from that point.  I tried it again by selecting the polyline icon and pressing the down arrow key instead of right clicking, but no options popped up.

In any case, I'm not sure that this would be an easier solution. When drawing assemblies, I don't necessarily know if some holes are going to be obscured as things get added, so the hole would have been drawn with the circle command in the first place.

[h_s_walker]

You need to actually start the polyline before you right click to choose the arc command.

OR use the DONUT command. You need to give an inside diameter and outside diameter. Make sure both of those are the diameter of the circle you want to draw.

[stephenP66RM]

Gotcha. I've tried it but whilst I can now create a start point and an end point for the arc, I have no way of controlling the shape of the arc, or which direction it will fall. I've not used the arc function of polyline before, mainly because I don't know how to control it. Up till now, if I want an arc on a polyline, I will just draw a series of straight polylines, and then add fillets were required.

[h_s_walker]

Yeah I have found the arc function a pain sometimes, but as I also said use the DONUT command

[stephenP66RM]

Having tried it now, I can see that the DONUT command works, provided I remember to make the inner and outer radii the same (unless I fancy peppering my drawing with silhouettes of hole reinforcers ) but this is only good if I make sure all circles are drawn this way to begin with.  However, the chances of that are remote, particularly if I am copying geometry from a previous drawing.

So, going back to my original question, is there any way of breaking a circle without using trim or redrawing it?

(I would like to add that although I am probably coming across as a real Negative Nancy with my responses, I really di appreciate you taking the time to answer my question and counter the problems I am facing!)

[h_s_walker]

Unfortunately circles cannot be converted to polylines.

[cadffm]

You can create a menumacro which can do this by two different ways.
1. Break circle (two points) and create your second arc which fills the gap.
2. Create two new arcs and delete the source circle.
Incl. layer and linetype handling.

But a well working macro for this goal needs much experience or time (or both), more time than my simple but correct answer.

I will try to give a sample without layer and linetype handling soon.

[cadffm]

That 's a simple possible way,

only for circles, without saving coordinates in variables , linetype-scaling and other things
And there are some other solutions possible, but something you have to learn, I just want to show that it can be worthwhile.

> Circle, 1break, 2break

It's your choose, select start-end point or end-start point,

^C^C^C_.SELECT;_single;\_.BREAK;_qua;@;_f;\\_.PEDIT;_qua;@;_close;;_.EXPLODE;_l;_.CHPROP;_p;_r;_l;;_ltype;HIDDEN;;
  or switch the order
^C^C^C_.SELECT;_single;\_.BREAK;_qua;@;_f;\\_.PEDIT;_qua;@;_close;;_.EXPLODE;_l;_.CHPROP;_l;;_ltype;HIDDEN;;