Settings for Importing

[kwolf]

Hi,

 

What options/settings have effects when importing a solid/surfaces to Mastercam? I usually import Solids to MC as surfaces and mostly, the solids are Parasolid and sometimes Pro/E.

There are "Max Surface Deviation" , "Sys Tolerance" and some others in Screen>Config. Are these settings have effects when importing solid? What other settings should I change?

Does it make a difference if I import a solid as a solid (not surface) ?

 

Thanks in advance

[Guest CNC Apps Guy 1]

Well if you have your tolerances too tight, you'll have problems with Solids. I'm pretty sure it's related to the Parasolid kernel.

 

My Tolerance settings are as follows;

[*]Tolerances

[*]Syetem Tolerance : 0.00005

[*]Chaining Tolerance : 0.0001

[*]Minimum Arc Length : 0.0002

[*]Curve Minimum Step Size : 0.001

[*]Curve Maximum Step Size : 100.0

[*]Curve Chordal Deviation : 0.0002

[*]Maximum Surface Deviation : 0.001

I have not had any problems with solids at these settings. The effect they can have is that you will not be able to modify the solid if the tolerances are too tight. It does make a difference if briniging in a Solid or surface. You won't encounter Parasolid errors if you bring in a surface then modify the surface.

I'd stick with solids though. I have far less problems with SOlids that with surfaces.

 

JM2C

[kwolf]

Thanks James,

I'm using Metric , should I multiply those numbers by 25.4?

I thought less "Max Surf Deviation" would result in less faceting problems too. Is it right?

And another Question:

Since Mastercam uses a parasolid kernel ,if importing a parasolid file as a solid in Mastercam , do those numbers have any effects?

 

Thanks again

[Guest CNC Apps Guy 1]

quote:

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I thought less "Max Surf Deviation" would result in less faceting problems too. Is it right?

---

Yes this is right to a certain extent. The tighter you make your surfaces, the longer it takes to create them, the longer it take MC to crunch them for toolpaths, etc... At some point you begin to see the limitations in the machine. It's a different point for every machine. None of the stuff I do here at work requires better than ±.0005" (or .001" total deviation) so those numbers work for me. As for multiplying by 25.4, ummmmmmm, I'm really not sure. I don't know if the numbers in the Metric CFG mean metric or standard. Sounds liek a good question for Greg McKay, though he's such a bum he has not been in here much lately. Perhaps he didn't like the ration we gave him last time...

 

quote:

---

Since Mastercam uses a parasolid kernel ,if importing a parasolid file as a solid in Mastercam , do those numbers have any effects?

---

Yes they do. If you try to create/miodify a Solid past it's(the kernel's) tolerance range, you can run into problems like "cannot create zero length line", etc...

[kwolf]

Hi again,

 

I have some problems in trimming/splittig imported surfaces.

I imported an IGES files and created an intersection curve between 2 sets of them . Now I can trim (with curve) one set but can not trim other set. Seems the intersection curve does not lie completely on one surfcae set even when decreasing the tolerance value "max srf deviation" to 0.0001 mm as well as other tolerances. I tried trimmig (with surfaces) but it can't do it. I want to know again is there ay other tolerance to set?

 

Thanks in advance

[Wallace]

Hi kwolf,

 

Never change System Tolerance : 0.00005 (metric or not)

 

My Tolerance settings for metric:

 

System Tolerance : 0.00005

Chaining Tolerance : 0.001

Minimum Arc Length : 0.01

Curve Minimum Step Size : 0.01

Curve Maximum Step Size : 100.0

Curve Chordal Deviation : 0.001

Maximum Surface Deviation : 0.001