Coordinate Systems and Construction Geometry

[Anonymous]

I've tried Fusion 360 out on a couple of real design projects over the last six months. I suppose I should add that I have many years of design experience with other systems. I find myself frequently frustrated by what appears to be limitations and/or inconsistencies that necessitate undesirable workarounds. I recognize that this may be (in part) due to an incomplete understanding of the Fusion methodology. Nonetheless, I would like to throw a few of these questions/comments out there in celebration of Answer Day.

1. Is it possible to create non-Cartesian coordinate systems? (Cylindrical and spherical specifically)

2. Is it possible to create more than one coordinate system in the same component? (Possibly coincident different types, possibly transformed same types)

2. How do I create a construction plane through an axis and at an angle relative to another feature (e.g., another plane)? It is important that this construction plane maintains the relative angle in the case where the reference feature rotates. (Note: This appears to be supported in the API.)

3. How do I create a datum point at a specific coordinate position relative to some coordinate system?

4. How do I create a plane perpendicular to another plane through an edge?

5. Axis perpendicular at point seems useless, since you can't reference a construction plane or sketch. Interestingly, axis perpendicular to face at point does allow a sketch as reference (inconsistent).

Perhaps some of these things have been addressed in recent updates. They reflect my experience as of February 2016.

[jeff_strater · Accepted solution]

Hi @Anonymous,

These are all good questions.  Unfortunately, we don't have great answers for most of them at the moment.  But, I'll give it a shot:

1. Is it possible to create non-Cartesian coordinate systems? (Cylindrical and spherical specifically)

Not today.  This one hasn't been requested that I have heard.  I'd put it on the Fusion Idea Station

2. Is it possible to create more than one coordinate system in the same component? (Possibly coincident different types, possibly transformed same types)

Again, no.  This one has been requested:  create-coordinate-systems, but doesn't have a lot of votes yet.  One question has always been:  What do you do with coordinate systems?  I'm not sure which commands would consume these objects.

2. How do I create a construction plane through an axis and at an angle relative to another feature (e.g., another plane)? It is important that this construction plane maintains the relative angle in the case where the reference feature rotates. (Note: This appears to be supported in the API.)

This one we should do, I agree.  The current Plane at Angle is under-specified.  It's on our list.

3. How do I create a datum point at a specific coordinate position relative to some coordinate system?

Is a datum point to you the same as a work point?  You can place a work point at the origin, then use Move to precisely position it relative to that origin

4. How do I create a plane perpendicular to another plane through an edge?

This is somewhat similar to #2.  A good idea, but probably not as high on the priority list as #2.

5. Axis perpendicular at point seems useless, since you can't reference a construction plane or sketch. Interestingly, axis perpendicular to face at point does allow a sketch as reference (inconsistent).

There is some history here:  Axis perpendicular at point was one of the first work geometry commands implemented.  It was, to be completely honest, easy to implement.  And, we never took it out, because a few people found use in it.

Thanks for the input

Jeff

[Anonymous]

Thanks for the answers, Jeff.

A few comments:

1. It it often easier to design axially symmetric parts in a cylindrical coordinate system. Similarly, spherical parts (yes, I have worked on a few).

2a. Since each component has its own coordinate system, the need for multiple coordinate systems is lessened. I could create a special component and move it.

2b. (Sorry about the numbering redundancy) Essential.  I was working on an axially symmetric part and needed to create features at specific angles to a base feature. Very frustrating without this capability.

3. There is perhaps more to the story. I really want to be able to create clouds of points programmatically, possibly based on tables of coordinates, possibly based on equations.

4. I agree that 2a will give me a solution, but I find creating planes perpendicular to other planes so common that a "short cut" is useful.

5. Ahh, history. I suspected this might be at work. Still, I think that any construction command that requires a "face" should also accept a plane.

[Anonymous]

Hi to everybody,

I should like to know some updates about the object; one specific use is in CAM 5 axis positioning.

In fact, in Manufacturing ( look at http://help.autodesk.com/view/fusion360/ENU/?guid=GUID29D1D526-292A-4322-A305-7D4744BEFEB1help)

• Manufacture 
•  Reference 
•  2D Milling Toolpaths 
•  Facing Toolpath
   I read: 

"Tool Orientation

Specifies how the tool orientation is determined using a combination of triad orientation and origin options.

The Orientation drop-down menu provides the following options to set the orientation of the X, Y, and Z triad axes:

• Setup WCS orientation - Uses the workpiece coordinate system (WCS) of the current setup for the tool orientation.
• Model orientation - Uses the coordinate system (WCS) of the current part for the tool orientation.
• Select Z axis/plane & X axis - Select a face or an edge to define the Z axis and another face or edge to define the X axis. Both the Z and X axes can be flipped 180 degrees.
• Select Z axis/plane & Y axis - Select a face or an edge to define the Z axis and another face or edge to define the Y axis. Both the Z and Y axes can be flipped 180 degrees.
• Select X & Y axes - Select a face or an edge to define the X axis and another face or edge to define the Y axis. Both the X and Y axes can be flipped 180 degrees.
• Select coordinate system - Sets a specific tool orientation for this operation from a defined user coordinate system in the model. This uses both the origin and orientation of the existing coordinate system. Use this if your model does not contain a suitable point & plane for your operation. "

How can I create User Coordinates Systems il Fusion360?

Many thanks

Piero

[nicolas_beaudoinPK47B]

User-defined coordinate systems are commonly used in injection molded or diecast part design to define draft directions, main and secondary. These will most often not coincide with the main coordinate system. For instance, the main coordinate system of automotive parts is ahead of the vehicle. In most other cases, the main coordinate system is related to how the component will mate with surrouding parts, which again, does not necessary coincide with draft direction.

One important aspect to keep in mind is that these user-defined coordinate systems need to be exported in neutral file formats for collaboration