Custom Fillet with Bulge

[jdrury54QED]

I am hoping to get help creating a LISP that will perform a custom "fillet" command. There are a few things to consider that I'm struggling with. The standard fillet command only works with two intersecting lines or two lines separated by a single segment. In my case I need to be able to select any two lines that will intersect regardless of how many segments separate them.

How I would like it to work. I want to run the command, be prompted for a radius (store the radius for quick repetition), then select my first line and the second line. Once the lines are selected, the second line will create an outside "bulge" based on the radius. (See image).

This will be used primarily for modifying CNC machining paths. Our nesting software will often produce the multi-segmented path (center in the image) which inevitably will cause an error at the machine. This "bulge" is a relief notch, so we don't have square inside corners. I had to painstakingly go through a large set of parts where there were hundreds of points I had to remove, then convert segments to arcs to get the paths to stop erroring out at the CNC machines. This would have saved hours.

Any help would be greatly appreciated.

[jdrury54QED]

In the videos, I noticed that the "red" lines are being created on top of the "white" polylines. I'm assuming this was done to illustrate the functionality. We would need this to append/modify the original polyline. Creating a new polyline object will break an important link between our drawing and the post-processing that creates the g-code. Specific information tied to the original polyline provides instruction for g-code and data for labels and reports. That may not make a whole lot of sense.

[komondormrex]

what is this specific info tied to a pline exactly? 

[jdrury54QED]

Hey Kent, I was not clear in my initial communication regarding "the first line should not be modified". I apologize for the miscommunication. My intent for that phrase was to ensure that the "bulge" did not occur on the first line selected - this is just to create a standard that I can teach to others. The first line selected may indeed need to be "modified" in the sense of lengthening/shortening it to allow the bulge on the adjacent segment to align.

I sincerely apologize for the poor description and lack of participation on this thread until today. I was traveling last week and had very limited time to check up on this.

[jdrury54QED]

The information is tied to its specific layer properties. The layer name, layer color, etc. Our other software, which is essentially a plugin for AutoCAD stores other information based on those layer properties - part name, part size, rotation, etc. Basically, we just need this to adjust the polyline, not create a new polyline.

Our current process for making these changes involves using the grip points of the original polyline - adding/removing vertices, converting to arcs, etc. On a recent work order, I had roughly 40 parts that had four "bulges" that were 7 segmented lines (very small lines which created an error at the machine). Each of those parts (polylines) had to be modified manually, using the grip point options. There were about 9-10 steps to remove points and convert these to true bulges (1400-1600 steps total to create working g-code).

[Moshe-A]

see message #10 i wrote this:

"if it is pline, the segment you pick can not be polyarc"

did you pick a line segment or arc?

[jdrury54QED]

I'm selecting a line segment of a polyline.

[Moshe-A]

i also wrote this:

"this version requires you specify bulge radius plus pick two objects (lines or plines)"

are you picking one pline or 2 objects?

[komondormrex]

@jdrury54QED

does it matter if updated pline changes its start point? i mean a closed one. 

[jdrury54QED]

For a closed polyline the start point shouldn't matter, but when it's not closed - typically for g-code creation - the direction of the polyline must remain the same.