Calling all Catia gurus

[gcode]

Here's a weird one

See the two attached files. 

Each is a step file containing  some points and a spline

The points came from a customer and define a lathe profile we will machine

The Catia file spline is wrong ( see the section the red arrows point too)

The Mastercam file has a spline created by the Auto Spline command and it matches our customer's spline.

SolidWorks does it correctly too.

Our Cati designer knows his business and he's baffled 

Any Catia guys know what's going on here??

We've dropped our Catia maintenance  ($60k/year) so sending this to Catia support is out. LOL

CATIA_SPLINE.stp MC2023_SPLINE.stp

[byte]

Are you using moldplus g?

wait thats a dumb question these are step files

[gcode]

Our Catia designer is drawing up a model and he thought the spline he got from those points is wrong

and asked me to check it out.

He was right, the spline is not correct... Catia is doing that spline wrong, Mastercam, SolidWorks, Spaceclaim and hyperMill

are doing it correctly.

I thought is very strange that Catia would make a mess of something so simple and I assume we have a setting wrong in Catia,

but I have no idea what.

Making splines like this is something we do hundreds of times a week here. 

I've never seen one go bad like this before... 

[byte]

i would start by checking the export tolerances in catia,  I daresay the issue isn't that Catia can't make a spline, have you tried other file formats like iges?

 

this page by AD covers what the default export tolerances in Catia are, you could try tightening them up a little

Alias 2017 Help | About importing and exporting CATIA V5 files (Windows only) | Autodesk

[gcode]

this is not an import/export issue

the points were  created in Catia, the spline was created using the points, and it's wrong

it may very well be a tolerance issue though

I'll check it out

 

Thanks

[cncappsjames]

Looks like it flipped the control point...

[gcode]

is there a way to flip it the other way??

[cncappsjames]

There is but that's above my pay grade... in CATIA.