OT break splines to arcs

[John King]

I do not do this very often, but normally when you are breaking splines to arcs what do you set your error to?

I was writing a program yesterday and it was getting so big I could not load all of it into the machine.

I figured the smaller the error the better the profile. The tolerance I have is .004 profile of a surface.

Thanks,

John

 

Mastercam X MR2

[John King]

bump

[mman10]

If you mean converting splines to arcs or edit simplifiy in X, I would use .0002 tolerance.

[Steve Zirtzman]

John,

The chordal deviation tolerance is also determined by the tolerances of the part you are machining.

 

What was your Total tolerance settings in your toolpath?

[Thad]

John,

 

Ever since I had to send a detail out to the welder, I always set the tolerance to .0001. The default setting was to delete the spline so I didn't notice how far off the converted curve was. After realizing it was way off is some areas, I brought back in the virgin file created the lines and arcs again and kept the original spline. It was off by .030 is some areas. This doesn't work too good when the die breakage is .004. Now my procedure is to set the tolerance at .0001 and keep the old spline. Compare the 2 and delete the spline when I'm done.

 

BTW, converting splines to arcs is not the same as Edit-Simplify. They're 2 different features.

 

Thad

[P_Scott]

John King,

 

I would listen to Thad on this one. He makes an excellent point. The default deviation value may be too large to give you the result you're looking for when matching with the part tolerances.

 

All,

 

Thad's statement here is also correct:

quote:

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BTW, converting splines to arcs is not the same as Edit-Simplify. They're 2 different features.

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Edit-Simplify is equivalent to V9's Modify-Convert to Arcs. It will only work if the original spline is nearly identical to a circle shape and can be redefined as a single arc with one radius. The best way to produce multiple arcs from a single spline is to use Edit-Trim/Break-Break many pieces in Mcam X. Use the deviation value and the lines/arcs button to replace the spline with multiple arcs. HTH

[mman10]

quote:

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BTW, converting splines to arcs is not the same as Edit-Simplify. They're 2 different features.

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I have learned something new. I always used edit simplify like convert splines to arcs. Thats why I read the posts, thanks Thad.

 

Thanks Pete, this is why you guys make the big bucks! Do you guys still have GenElMec in Bpt CT as customers? I used to work there.

[Thad]

quote:

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I always used edit simplify like convert splines to arcs.

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Different from V9, Edit-Simplify can be used on lines too.

 

From Help...

 

quote:

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Use this ribbon bar to convert circular shaped splines to closed arc entities (circles). You can also convert splines that define lines into line entities.

Mastercam converts a spline to a closed arc only if all of the spline’s control points are within the specified tolerance, when measured against a circle that passes through the spline’s endpoints and mid-point.

 

Tip:

 

This function is particularly useful if geometry that is supposed to denote circles, arcs, or lines is read into Mastercam as splines during a file conversion.

 

By working with closed arcs instead of splines, you can more easily and accurately reference the centers of the circular geometry or dimension the circles.

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Edit-Simplify seems to be one of the most misunderstood features in MCX. Well, along with picking drilling points by Entity.

 

Thad

[P_Scott]

mman10,

 

quote:

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Do you guys still have GenElMec in Bpt CT as customers?

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Yes we are still honored to call Gen El Mec our customer. Dean's been quiet lately but I know he's busy keeping things in order. I remember a training class I conducted in Milford with him in it. It was a couple of years ago in Jan. or Feb. The last day of class it was sunny then blizzard then rainy then sunny then blizzard...

[Colin Gilchrist]

Thad,

 

Hopefully they will fix the Entity selection thing soon, so Edit Simplify will become THE most misunderstood feature. We can only hope...

 

-Colin