offsetting causing a small 0.0001 line if the piece is p edited from using a certain edge

[Anonymous]

We work in manufacturing countertops.   We have to offset the countertop final measurement by 3/16" to be cut for extra material to run on our CNCs.  If we p edit a piece using the front edge as the starting point and then do an offset it creates a small 0.0001 section of a line on the offset if the piece was p editing from the front edge.   If the piece is p edited from any other line in the piece the offset doesnt create this small line.

Our sawing software recognized this line as a problem and the drawing has to be fixed.

Is this a common issue?

[steven-g]

Can you post a file showing this error and point out where this line is (it probably isn't visible) 

[Anonymous]

Here are a .jpg of the problem and the attached dwg.  The problem is at part #1 right where the line is near the 1.  The original is fine but the offset is produced with a small 0.0001 line.  You can kind of see it because the pattern of the blip and the longer blip is messed up.  And when you really zoom in you can see it.

It doesnt happen often , just a few times a day but our saw software doesnt like them and we have to find out where they are and erase the little line and reconnect it.

Any ideas would be appreciated.

[pendean]

Is your CNC machine also struggling with these separate but inline line objects too?

[Anonymous]

No CNC has no problems.  The problem happens in the software for our new saw.  It doesnt want to program it because of the little line.  The lines are all crooked because they are scanned to follow the walls of the house. 

Our saw uses a blade and waterjet so all the lines are no problem, it is just that tiny line, it seems too small and the saw software doesnt know what to do with it.

It is weird because it only happens once in awhile with the offset causing this problem.

[pendean]

I was not able to detect the other line in your posted DWG file, can you repost with it in place and zoomed to that level?

I suspect your PLINE offset is adding an element, it happens with PLINEs when Offset in certain directions, its ben around forever in AutoCAD. You often just need to find it and eliminate it, or not use PLINE objects in the first place (hence my question).

[Anonymous]

We have to p edit them to do the offset for the saw drawing.  We cut the counters with an offset of 3/16 so that we

have material to take off on all sides on the CNCs so that the pieces come out exact.

I tried joining instead of pedit but the problem occured more frequenetly.

[steven-g]

How do you create the original polyline? the problem is that this vertex is the start/end of your polyline. And it isn't a tiny line that is being created it is actually an arc. I cannot yet see why it should do that but no doubt the two segments on either side of this vertex are ever so slightly at different angles to each other and when you use the offset command it is only offsetting perpendicular to those two endpoints. Normally offset would extend the straight segments to a new meeting point but in this case, it is filleting just that joint.

Knowing the workflow you use to create the original polyline might shed some light on why the error is happening.

And the problem with your CNC is not because the line is so small it is because CNC programs don't like arc's they only work with straight segments.

[pendean]

[Anonymous]

The original drawing is created by our templaters using a laser templater.  They snap points on the wall that create lines that will follow the crookedness of the walls.  So they will start near a corner go a distance snap another point and so on.  They all use LT-55 lasers.