Radius/Chamfer callout 1

[clydetheglide]

Has anyone out there ever seen (C/R) used as a callout for an optional chamfer/radius? Is it in the standard?

 

[KENAT]

Assuming you work to ASME standards (when asking this type of question I suggest you specify what standards you work to.)

ASME Y14.38-1999 got rid of most / so I doubt it's in the standard, at least any more.

CR could be, change request, combat ready, component repair, continuos rod, controlled rectifier or credit per 14.38

In ASME Y14.5 CR is controlled radius in Fig C-3 and 3-8

Don't see it elsewhere in 14.5 from a quick look.

So I've never seen it and wouldn't necessarily know what it meant if I did.


KENAT, probably the least qualified checker you'll ever meet...

 

[meintsi]

No.

and NO.

Remember...
[navy]"If you don't use your head,[/navy]
[navy]your going to have to use your feet."[/navy]

 

[JsTyLz]

controlled radius

 

[ewh]

I have seen CR (controlled radius), but never C/R. In this situation I have usually seen a flag note next to the dimension callout, be it either chamfer or radius. The note would specify that the other form was permissible where indicated.

 

[KENAT]

Agreed ewh, the OP didn't ask for advice how to handle the situation so I didn't put it but I'd handle it how you just detailed.

In fact our general note on removing sharp edges is:

REMOVE ALL BURRS AND SHARP EDGES ____ MAX RADIUS OR CHAMFER.

(the ____ gets filled in based on each parts function/size etc)

KENAT, probably the least qualified checker you'll ever meet...

 

[clydetheglide]

Thanks for the input. I had never seen it used and was wondering why someone put it on a mark-up. I, too, would use the flag note method, which is what I think I'll do.

 

[ewh]

Thanks, KENAT. I have found myself responding as you did with just the facts that they ask for, only to find that they really wanted more of an explanation. It seems to not help as often as it does help, but sentences are cheap. One thing I learned in quality training is to give them what they want/need, not just what they ask for.

 

[EngJW]

You could dimension the chamfer and then add "optional R.xx"

 

[KENAT]

ewh

Hmm, I've kind of learnt the opposite from being burned too many times when trying to help.

Sometimes my guess of what they really want is off too!



KENAT, probably the least qualified checker you'll ever meet...

 

[ctopher]

I have seen CR. I have also seen FR (FULL RADIUS).

You could dimension the chamfer and then add "optional R.xx"

I would not add "OPT R.XX" after a CHAM. I think it is unecessary to R a chamfer, unless the design requires one. It would be more difficult to control a R.
I think I would have a genersl note for breaking corners or a MAX R, like R .002 MAX.

I think the safer way to go is if you need a radius, call it out with tol ... same for cham. Don't assume the machine shop will understand.

Chris
SolidWorks 07 4.0/PDMWorks 07
AutoCAD 06
ctopher's home (updated 04-21-07)

 

[EngJW]

How would you radius a chamfer? Maybe it's not clear if you point to a corner and say .03 x 45 deg, and then on the line below you say optional r.03, I don't know. You could have a part that is normally chamfered, but one day purchasing sends it out and the new place wants to use a radius instead. Part functions the same either way, but you wouldn't want to make a drawing change everytime the part gets moved around.

 

[ctopher]

I meant the corners/edges of the chamfer.

Chris
SolidWorks 07 4.0/PDMWorks 07
AutoCAD 06
ctopher's home (updated 04-21-07)

 

[fcsuper]

From my past experience, this has been a method to callout either a chamfer or radius at the same time. I wouldn't use this method myself. Under the instruction of a boss, I've used a note modifier that added "RADIUS OK" or "CHAMFER OK" (depending on which was spec'd), and I'm kinda on the fence as to whether or not that is an ok method.

Matt
CAD Engineer/ECN Analyst
Silicon Valley, CA
sw.fcsuper.com
Co-moderator of Solidworks Yahoo! Group

 

[aardvarkdw]

I would stick with a flag note. It puts less clutter on the drawing and gives you the chance to explain what it is you want rather than opening yourself up for lots of questions from your fab shop.

David