Why no Axis

lonnie_1

Just curious as to why there are no Axis in OnShape.  Or am I just missing something?

jakeramsley

Lonnie said:

Thanks for the responses.  I understand you can work with out them I just was more curious as to why they are left out.  I guess they feel they are just not really needed.

I don't think saying we don't feel they are needed is a fair characterization, but forcing default axes adds clutter and in my opinion isn't needed.  We have requests for additional reference geometry and it will be something we will continue to implement.  However, as Traveler pointed out, there are ways to create geometry to get the axis desired as well as geometry naturally falling out of the design process to infer the right axis.

Right now you can use circular edges, sketch entities, and cylindrical faces to infer an axis at the center of circle/cylinder.  You can use straight edges or sketch lines as axes as well.

traveler_hauptman

The workaround I currently use is to sketch a construction line where I want the axis datum on a new or existing sketch. Constraints and feature references to that will work as expected.

I was annoyed at this lack when I first started using Onshape but I have found that it works fine to not have reference axis. Axis are not needed for mating. For feature construction, the above technique works fine.

3dcad

What about circular pattern in assembly (when available)?

traveler_hauptman

I think using circular and edge geometry works ok.

Don't get me wrong. I would not mind an axis feature.

3dcad

I'm thinking of situation where you wan't parts in circle and nothing in the middle..

I have requested default axis but I got answer that most likely this is not going to happen. Possibility to create axis is under review.

I'm great fan of templates so I would propably just create axises into template studios - should be as good as default.

traveler_hauptman

If I'm understanding correctly, the current approach works fine for what you want.

The template idea is good.

lonnie_1

Thanks for the responses.  I understand you can work with out them I just was more curious as to why they are left out.  I guess they feel they are just not really needed.

jakeramsley

Lonnie said:

Thanks for the responses.  I understand you can work with out them I just was more curious as to why they are left out.  I guess they feel they are just not really needed.

I don't think saying we don't feel they are needed is a fair characterization, but forcing default axes adds clutter and in my opinion isn't needed.  We have requests for additional reference geometry and it will be something we will continue to implement.  However, as Traveler pointed out, there are ways to create geometry to get the axis desired as well as geometry naturally falling out of the design process to infer the right axis.

Right now you can use circular edges, sketch entities, and cylindrical faces to infer an axis at the center of circle/cylinder.  You can use straight edges or sketch lines as axes as well.

lonnie_1

jramsley said:

Lonnie said:

Thanks for the responses.  I understand you can work with out them I just was more curious as to why they are left out.  I guess they feel they are just not really needed.

I don't think saying we don't feel they are needed is a fair characterization, but forcing default axes adds clutter and in my opinion isn't needed.  We have requests for additional reference geometry and it will be something we will continue to implement.  However, as Traveler pointed out, there are ways to create geometry to get the axis desired as well as geometry naturally falling out of the design process to infer the right axis.

Right now you can use circular edges, sketch entities, and cylindrical faces to infer an axis at the center of circle/cylinder.  You can use straight edges or sketch lines as axes as well.

jramsley thanks for the reply.  I did not want to sound like I was implying they should or should not be there     For me, once I understand the idea behind something it is easier for me to apply to other situations.  I would rather learn to use OnShape the way the developers intend it to be used and try not to bring any preconceived notions from other software about how it should work.

andrew_troup

I would personally very much like to be able to save a template with the construction planes renamed XY, XZ and YZ, and with named reference axes for X, Y and Z.

Dedicated sketches would be nearly as good, but here's why I would prefer formal reference axes:
In a complex mechanism design, certain axes are important elements, which need to be available from within various assemblies. 

They serve a similar purpose, in models involving lots of rotary movement or translation in specific directions, to what reference planes provide in the more general case.

The ability to easily switch designated reference axes 'on' in those assemblies, in order to access them, and 'off' in order to declutter the model, is valuable.

Such access is required not just for mating, but for measurement, orientation, and "assessment of possibilities". 

There may be other ways of achieving the same end, and they may be preferable. 

For instance, perhaps the development team could consider a "flagging" approach, where users could flag sketches for key characteristics according to a schema of their own devising, allowing future filtering (for selection, display, or whatever else).

Something like this might be more flexible and powerful, and would not introduce any complications to the models of those who had no need of the capability.

Alternatively, mate connectors might serve dual purpose as reference axes. We can already rename them; perhaps we could be enabled to drag the primary axis longer, to identify those which double as a reference axis, and make the location of that axis stand out in a complex assembly.

andrew_troup

Regardless of how OnS decide to provide some of the attributes of a reference axis, it seems desirable (essential in some cases) that they be usable to define most of the following:

1) Axis for linear and circular patterns
2) Tangency direction for lofts or surface patches (along all boundaries)
3) Direction of extrusion or offset or thicken
4) Direction of pull for draft
5) Direction for definition of silhouette edges, split lines, projection of sketches onto faces

david_ayers

I am trying to create a plane through the center of a hole (extruded removal of a circle) and NEED AN AXIS, and then define the angle of the plane relative to another plane/planar surface.  For Part Studio to be useful for me, in this case, I need a plane onto which I define/build my cover.  Then after I design the cover, I want to change the plane definition (angle) so that I can tell that it will fit at two orientations about that axis.  Please don't suggest that I should do this in an assembly -- then you can't really say Part Studios is the way to go.  I still have to define the cover part, and whether or not I have the ability to rotate it in the Part Studio, I want to do so from the plane of my choice as it is key to my design intent.   Sorry, but I really feel in handcuffs (workarounds) with this software too much of the time.   

baumar

The trick with the helpline made coincident with 2 planes is cool, thanks! I think it would be worth to be added in the documentation where I searched quite a while without finding anything

andre_brown101

I am trying to make a reference plane (so I can do a sketch).  the plane should be parallel to one of the default planes, say the right plane, and then I want to use the axis of a cylinder to define the "point" that onshape is asking for in the new plane workflow.  I can't seem to use a mate connector as a point for this which is annoying.  In SW, I would have just turned on the visibility of inferred axis that show all the axis for all cylindrical faces, then select this in the plane definition step.  no additional sketches or axis needed in the feature tree, so no extra clutter.  It appears from above that I have to make a sketch perpendicular to the axis to infer the center of the cylinder, and this is annoying and clutters my feature tree.

eric_pesty

andre_brown101 said:

I am trying to make a reference plane (so I can do a sketch).  the plane should be parallel to one of the default planes, say the right plane, and then I want to use the axis of a cylinder to define the "point" that onshape is asking for in the new plane workflow.  I can't seem to use a mate connector as a point for this which is annoying.  In SW, I would have just turned on the visibility of inferred axis that show all the axis for all cylindrical faces, then select this in the plane definition step.  no additional sketches or axis needed in the feature tree, so no extra clutter.  It appears from above that I have to make a sketch perpendicular to the axis to infer the center of the cylinder, and this is annoying and clutters my feature tree.

You can just put your sketch directly on a mate connector Use the cylinder centerline and just re-orient the MC primary axis to the default plane. No need for a plane or any construction geometry at all in this case.