issue with trimming circle

[Beertestr]

OK. Been using AutoCAD for 15 years off and on, so what I am trying to do should (should) be a no-brainer. Admittedly, there is a gap in usage between using R14, and 2007. I still have a copy of R14 at home I rarely use.

1) Drew a circle.
2) Drew a line (chord) through a section of the circle. Line intersects the circle in two places. Everything is in the XY plane.

3)Selected trim command.

4)Selected cuting edge (line)

5)Tried to trim the smaller section of the circle, leaving the larger portion. Did this by selecting the smaller section. AutoCAD removes the larger. Hmm. I undo and try again, this time selecting the larger section of circle, thinking that the function works opposite of what I used to. IT STILL removes the larger section, leaving the smaller section.

I have tried this several (20?) times, redrawn the line and circle again to make sure everything was in plane. Same result.

I toggled PICKAUTO and PICKADD, as well as EDGEMODE in various combinations. Does not make a difference.

I even tried drawing two cutting edges, so that I would remove 90 degrees of the circle. No luck.

The trim function ALWAYS removes the larger portion of the circle.

So I tried another experiment. I drew another line vertical line (again in the x-y plane), and drew a circle with it's center at the midpoint of the line. The line intersected the circle. Using the TRIM command, it will only ever trim the same side, no matter which side I pick. In other words it will always remove the left side of the circle, ALWAYS.

This is frustrating, there has to be a fix for this.

any other variables I can toggle on and off to see if it will fix this?


Mike

[SEANT]

How does the command perform if you type .trim at the command line?

[Secretagdan]

From time to time I have the same problem, with trimming in general. Sometimes you need to extend your trim lines past the line you want to trim, so that it will trim. It does not seem to happen all of the time though, but it is annoying.

[Car5858]

You can also brake the circle in the area that you wish to trim. You may also want the intersection onsnap slected. Just be carefull which direction the brake is.

[Beertestr]

How does the command perform if you type .trim at the command line?

Does not matter if I type .TRIM , TRIM, TR, or select the trim function from the Modify pull-down menu. It does not work properly.

From time to time I have the same problem, with trimming in general. Sometimes you need to extend your trim lines past the line you want to trim, so that it will trim. It does not seem to happen all of the time though, but it is annoying.

All the cases I have tried have the line intersecting the circle in 2 places, and extending beyond. I tried to just draw an arc, but AutoCAD defaults to the smallest ARC it can generate, so if I tried to create a partial circle with same geometry as I was attempting to to by trimming with a chord through the circle, I ended up with the smaller portion.

The trim command always pics one side to trim, and never changes.

FYI, I tried to trim two intersecting lines, and that seemed to work fine.

This is maddening. I have tried moving the UCS to be in plane (not just parallel), I even input the line(s) and circle by hand entering the coordinates to make sure they are in plane... same result.. simple 2D commands are keeping me from some 3d modelling. I have even tried to select both objects as cutting edges, even though I only want to trim one object only.

ridiculous

[rossi_mac]

Never heard of such a prob, does this prob occur in R14? I'm on '02 and it's fine. Perhaps someone on '07 should have a play.

Anyway I'm not a guru but just a thought.


1) Do you have osnap on, sometimes when I offset it automatically chooses perpendicular and offsets the wrongside.

2) Units, does it draw the circle clockwise direction which affects the sector of the circle, no rubbish idea! I dunno sorry.

[eldon]

When you start the TRIM command, and it says select the cutting edge, if you do not pick any object but just hit Enter, then every object on the screen is a cutting edge. Then just pick the bit you want to trim.
Otherwise your trimming is behaving in a very eccentric manner

[Coosbaylumber]

Had this problem years ago. I was using CheapCAD then, and "visually" it looked un-trimmed, but numerically is was cut, for could not pick any place on visable curve, only on the remainder, and the cure plotted fine anyway.

My solution was to cut the curve in a number of locations, then extend the curve into one of the lines in sections at a time until it came up looking like as anticipated. Swap the file to another computer, look at it, then do more if required.

In R-14 is could very well be trimming as you are thinking, but visually it is not then.

In a later on release of CheapCAD, the poor visualization was fixed, but zero mention from the company.



Wm.