Create Circle End Points Problem

[ChuckK]

I apologize if someone has brought this up before but I just noticed it today, I did a search and didn’t find anything.

With version X MR2 I have found a problem with the Create Circle Edge Point tool that is somewhat unpredictable but can be reproduced. Follow these steps to reproduce the error.

Pick the Create Rectangle tool and create a square with these corner coordinates

-1.2345,-1.2345 and 1.2345,1.2345

Pick the Create Circle End Points tool and click on the top right corner and the bottom right corner.

Use the Trim Three tool and trim it so it looks like a key with one end rounded.

Now use Analyze Entity Properties and click on the arc. The arc should be a 180 degree arc but it’s not. Mine is usually a little over somewhere around 180.032. Also the start and stop points should be 90 and 450 but there not. The angles very a little every time you do it but there never right. However if you repeat the same procedure with a square that has corner points of -2,-2 and 2,2 it works flawlessly. I have two seats of Mastercam on different computers one has an ATI card and the other an NVIDIA and both computers do the same thing. Also I know it’s not a problem with the Analyze Entity tool because I found the problem when I posted a file for one of my older mills (one that can only do 180 degree arcs) and noticed some weird looking code where I had used the Create Circle End Points tool.

[Steve Zirtzman]

Chuck,

I get similar results on a fresh install of MR2, but the problem is not the Create Circle Edge Point function, it’s in Trim/Break. If I Analyze just the arc, it’s good. If I break the arc in two pieces, it’s good. But after the arc is trimmed, I see the error.

 

I have experienced problems like this before while testing the Mask on Arc function with a pattern of arcs that grew in diameter by only .00001 inch. I changed my System tolerance in Configuration to (.00001), and your arc trimmed perfectly. I would like to hear Mastercam’s explanation of this.

[ChuckK]

Steve,

I think your on to something with the trim tool but there has to be a little more to it. If I go through the same scenario but use Create Circle Center Point and click the mid point and end point to make the arc it trims perfectly. Also I found that if you create the arc using Create Circle Edge Points with the vertical and horizontal lines extended, so you’re picking intersections instead of end points, it will trim properly. I’m going to bump up my system tolerance like you said and try that for a while.

 

Thanks

Chuck

[Steve Zirtzman]

Chuck,

Send your problem to QC. I would like to hear their reply.

[ChuckK]

Steve,

Changing the system tolerance didn’t work for me. How would I send this to QC?

 

Chuck

[Steve Zirtzman]

[email protected]

[beej]

I just tried it and got the same thing, although it worked right when I used divide rather than trim

[ChuckK]

I sent the problem to QC and it has been logged as defect # CNC 00021351. They also told me you can use the “E” power key as a work around.

 

Chuck

[Steve Zirtzman]

The "E" power key?

[ChuckK]

Yep it was new to me too. It's under the Autocursor options as a checkbox. Once checked you can use "power keys" to force the following selections

O - Origin

C - Arc Center

E - Endpoint

I - Intersection

M - Midpoint

Q - Quadrant

P - Point

[Storkman]

So if the power keys work must be an autocursor issue.

[Rob Peirolo CNC Software]

Try it in V9.

It works the same way.

[Steve Zirtzman]

I know about the power keys, I just can't believe that is the work-around.