2D Drawing Axis crosshair orientation.

[Paul6]

I have a circular part  with a rectangular keyway in the front plane.

I have created an axis in the part normal to the front plane and referencing the right and top planes with 0.0 offsets. This is prior to creating any geometry.

In the drawing of the part the axis crosshair is shown in the vertical plane and horizontal plane parallel to the keyway when the view is shown as front.

If I rotate the front view by axis angle 45°, the axis crosshair are no longer shown as referencing the right and top of the part and parallel / perpendicular to the slot.

Is there a way to have the axis cross hair fixed to the datums in the part, so that when the part is installed in an assembly , the angular dimensions can be called out  depending on the position of the keyway. And if the part is rotated in the drawing the axis stay aligned to the keyway.

Any help on this would be greatly appreciated.

[kdirth]

Select axis, RMB, Edit Attachment

Menu will pop up to select desired attachment.

[Paul6]

The axis attachment is already aligned to the top and right datum planes in the part..

What are you suggesting should be selected as references? 

This is the view I am wanting when the part is rotated.

In the drawing I can manually rotate the axis, but that requires knowing the angle the part is rotated.

As the drawing will have multiple views of the parts movement, with variable angles this would not be a suitable solution.

[KenFarley]

What he meant is you can select the offending axis, then hold down the right mouse button, and the option to "edit attachment" will come up. Select that, then pick one of the short sides of the slot. It will orient the axis to be perpendicular to the selected edge. This is only going to affect the axis display in the specific view in which you do the modification.

Alternatively, you could define a set of axes that lie in the front plane of your part, and are normal to both faces of your slot. If this is only one such feature you need to display axes for, it might be the simplest approach, since the axes will always be oriented as you wish.

[Paul6]

Hi Ken, thanks for the clarification, however I am still not sure I am getting the result I am wanting.

If I pick the axis and edit attachment, and replace the right datum with the short slot surface, the axis no longer concentric to the cylinder. The crosshair in the drawing when the view is angled at 45°, the cross hair remains in the vertical and horizontal planes.

If I use the alternative method suggested to create a set of of axises on the front plane and normal to top and right datums, I agree you are able to select the 2 axis in the view to create a virtual / fake cross hair.

Dual axis

An alternative method would be to create a sketch of a cross hair on the front plane of a cross hair and use that as the fake cross hair.

sketched fake crosshair

However what I am wanting to achieve is to have the cross hair of the single axis which is concentric to cylinder and constrained in orientation to the top and right datum planes. So that when you rotate the part in an assembly mechanism the cross hair rotates to indicate the change in position.

[StephenW]

In the drawing (not model):

What you have:

To get the aligned, select the axis, right mouse, edit attachment:

Then select Parallel and select the line you want it to be parallel with (there are other options here, explore them too for future reference.

[tbraxton]

This drawing is using the same axis (axis 3) in the model to display the crosshairs as you specify on the drawing in two views. In the auxiliary view with the keyway at an incline the method provided by @kdirth is used to change to orientation of the cross hairs in the aux drawing view. This method does not update the orientation of the drawing cross hairs if the clocking angle of the aux view is changed in the model. One would need to manually define the attachment in the view when changing the clocking angle.

If you need a visual reference of the clocking angle in mechanism mode, then I would suggest you add a feature to the model (sketch) as this will update upon regeneration of the mechanism model.

[KenFarley]

I was under the impression you were talking about changing the displayed axis lines on a drawing, not in the model.

An axis is just a line in 3D space. Basically, a point and a direction. There is no definition of which direction the axis lines should go when they happen to be normal to the current viewing plane. They are always drawn with vertical and horizontal lines with respect to the current view. A convenient display thing but not something that can be used for dimensioning in an assembly.

For the cylindrical body with a rectangular slot depicted, if I needed to position it in an assembly I'd use the following:

(1) Position it using either the outer cylinder or axis to locate in "X" and "Y".

(2) Use one of the faces of the cylinder to locate it in "Z".

(3) Add another constraint and use any of the faces of the rectangular slot to define a "clocking angle".

[Paul6 · Accepted solution]

Hi All,

Thanks for your suggestions on how to show a cross hair in a drawing of the axis in a model.

I understand now that what I was hoping to display in a drawing or model, is not the default for creo. 

It appears that I would require additional feature / axis etc in the model, to achieve the desired ability to measure the clocking angle. 

[KenFarley]

You do not need any additional features or axes to measure the angle, as long as one of your edges in the hole (rectangular in your images) is a straight edge. You can measure using the edge on the face of the object, or the plane defined by the extrusion of the line. If you always have a plane at the center of your part you could use that. You only need an additional axis if you absolutely insist on having an axis depicted in any drawings made with the part and/or its assemblies.