【转帖】cl attached to a centerline

yang686526

"cl" attached to a centerline
when is it appropriate to attach a "cl" symbol to a centerline? is it ever nessesary? is this part of a standard somewhere? does anyone do this on a regular basis?
oh the joys of writing cad standards.
david
find a job or post a job opening
without specifying what it is the centerline of, it serves no function that the line font doesn't already.
the example i am trying to reconcile is non-round part with a round feature in the center. the majority of the features are dimensioned from this round feature. there is enough detail that a hiddenline view is counterproductive.
so i have features on the outside surfaces of the part that must be dimensioned from the round feature in the center of the part, but you cannot see the round feature in the side views where these other features are.
hope that isn't too confusing. should i show the cl symbol on the side view centerlines for clairity or is it enough to have just the centerline and a center mark in the top view? i would post a pic but i cannot due to proprietary rules. if you need one perhaps i can sketch something to illustrate.
it would be appropriate whenever it helps to make the drawing unambiguous, clearer & easier to understand.
that is the same thoughts i had; it doesn't serve any function that the linetype doesn't already exhibit, and that it is superfluous unless it helps to clarify the drawing. is this in a standard or is it just an accpeted practice?
i would specify what feature it is the centerline of, such as "cl dia .25"
the only time (sometimes) i use cl is when clarifying the center of the part. only to clarify the features of the part.
using a centerline font thru the axis of a  circle feature without the cl is correct.
chris
systems analyst, i.s.
solidworks 06 4.1/pdmworks 06
autocad 06
i wouldn't use cl.  it is quite unnecessary and may not be universally understood depending on how you represent it; i.e. c.l., cl, c/l, or c&l superimposed.
if possible, show the hidden geometries in phantom lines so that the feature can be identified.
an irregular-shaped piece also has a centerline, so showing the centerline of the circle only would be misleading if it were not centered.  in that case, i'd show the centerline of the workpiece with a visibly longer line than the centerline for the other features.   
jim sykes, p.eng, gdtp-s
profile services
cad-documentation-gd&t-product development
unless the geometry is a diameter, a centerline doesn't necessarily indicate the center of the part. to prevent misinterpretation, it's wisest to dimension to the centerline from an edge or another feature if the intent is to dimension other features off of this centerline. i agree with the others that adding a cl is superfluous. from the original description of the drawing, it sounds like a section might also be helpful.
what would a centerline represent if not the center of the part (provided no diameters were present)?
cl once was used to represent the axis of symmetry. it is now practice to use symmetry symbol in lieu of cl; however, at my company we still use cl(superimposed).
wes c.
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