Repeating Datums

[dakeb]

Guys,

WF3. When I show flat plane datums on a drawing ProE allows me to repeat them as many times as I want in as many views as I want. No problem.

However, the same is not true for datum axes (from a cylindrical surface). I can show it in one view, and it disappears in another.

Why can I repeat flat datums but not axis one?

Cheers,

Dave

 

[PeterStock]

An axis should by standard refer to a particular surface. Just showing it on a axis is not correct per the ASME standard. A datum plane is clear (or should be anyway) as to what the surface is when it is shown on multiple views. What I had done to identify an axis in more than one view is to point to the axis with a note, i.e. "AXIS OF DIA B" or "C/L OF DIA B".

Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services

http://www.infotechpr.net

 

[dakeb]

I am trying to show the axis datum in various views on the surface of the cylinder. I can show it in one place only, on the cylinder diameter dimension. In other views I am having to create an additional cylinder diameter dimension and show a sketched datum symbol on the leader line (after deleting the dimension text with @o to avoid double-dimensioning.

ProE will allow me to show the datum in multiple views if I attach it only to an axis (by showing the axis - not the datum), but as soon as I attach it to a diameter dimension it disappears from the other views.

I assume that ProE regards it as double dimensioning, even if the additional diameter dimensions in other views are reference only.

I don't think the drafting standards prohibit showing repeat datums in multiple views so ProE is being unfairly restrictive, irrespective if I am working to ASME or ISO.

Dave