Default CSYS Orientation

[donha]

My company has adapted a default CSYS orientation of looking from a plan view and seeing XY with Z facing towards you. I have been told the reason for this is to support the CNC folks. From a CAD (my) and PTC's point of view this seems incorrect. Does PTC differ from other CAD systems? Is there no industry norm? Can someone tell me why the CNC folks want the CSYS oriented differently?







Edited by: donha

 

[appinmi]

If the CNC folks are using ProNC, then it shouldn't matter where you put your CSYS. They can create their own. I use Proe for modeling and CNC programming, and I have found that when the designers put a CSYS on their model, it usually comes from a point that cannot be controlled in a setup. Therefore, I have to create my own anyway.


If they are using some other CAD system, theyshould be able to rotate & shift the model to wherever they want to put the CSYS in the proper locations.

 

[Zaki]

Hi dear


Actually there are a lot of guys using csys in proe part modeling and most of them dont know why? they have no use of it. I dont use csys in part level untill I need it for some real reason like equation curves, csys points or any other feature that must need a csys. Otherwise I dont use it bcoz in design there is no need by default to use a csys unless u need it for a feature, other thing is that whenever u go for machining u can easily create ur own so I dont use it in part and only use it at machining level and I had make my machining template for my department use.

 

[Huug]

There are some reasons to have a coordinate system in a predefined direction. I know a few:

In the mould making industry it is a standard that the Z-axis is the opening direction of the mould.

What I do in general is when a plastic part is ready I create a MOULD csys at the middle of the parting plane (whenever that is flat) with the Z-axis in de mould opening direction, and than export it (Iges and Step) using that coordinate system.

Off course a mould maker can reorient any part and create any coordinate system at any place in his favorite direction, but with a part of mine, he doesn't have to. When he opens my file, it is directly oriented in the right manner. So it's more a kind of service that you provide with your part, as a sign that you have thought about the preffered (or obvious) mould direction.

Another situation where the orientation of a coordinate sytem is of importance is in Rapid Prototyping like Stereolithography or Laser Sintering. Most of such machines are based on Layer Manufacturing Technology, where they slice a STL file in the z-axis. In general, it is recommended that you slice a part in that direction (height, width or depth) that is the smallest, so the built-up time is the shortest and therefore the cheapest. Most of this Rapid Prototyping Service Providers reorient a part themselves to get the most economic built-up direction, but at some major agencies the quoting process is automated. At that point it is wise to export your file to STL using your own csys that you have created and oriented especially for this prototyping process.

The last important use of a predefined coordinate system I know of is in the world of electronics. Any Printed Circuit Board should have a reference csys that has the Z-axis perpendicular to the top surface. All the components on a PCB should have a csys with the z-axis matching the top surface of the PCB. This csys should also match the electronic layout of any component. When importing and exporting ECAD files (.emn and .emp) this is of extreme importance.

Huug

 

[csusie]

The most fundamental reason it points toward you:


If you are looking at the plan view and the x axis points to the right and the y axis points up, the z axis has to be pointed towards you, its the right hand rule.


If the x was up and the y was to the right then the z axis would be into th page but that would just seem awkward.