All around radius callout

[microdesign]

I am seeking the proper, complete, and unambiguous method to call out a radius on a corner.

I currently show a radius leader in each view with a radius arc. (example cross-section view)

I have a chassis which I would like to radius on 3 edges coming to a corner. I realized that the individual callouts would still not mean that the corner was fully rounded.

I am tempted to use the all around symbol, which I am OK with, but the radii do not go around all edges of each surface. Think a cube with the top face fully radiused, and the side faces radiused on their top and vertical edges.

Anyone?

 

[Heckler]

ASME Y14.5M-1994 Para 3.3.18:

Best Regards,

Heckler
Sr. Mechanical Engineer
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"Coming together is a beginning, staying together is progress, and working together is success." - Henry Ford

 

[microdesign]

Thanks Heckler,

Yes, I am aware of the callout, but suspect whether it is on to use.

I am trying to dimension "ball corners". In the view where it is appropriate to call out the radius domension, it is not appropriate to call out the all around function. Is there a "ball" or spherical corner callout?

 

[ewh]

If you have a cube as you describe, you would call out "8X R.XX". The spherical corners will be a result.

 

[microdesign]

Thanks EWH, but no sir! Assuming the same radius dimension on each edge, radiusing each of 3 edges leading to a corner will NOT cause the corner to be fully rounded! The "shank diameter" of the radius cutter must follow the radius of the third edge radius while cutting the first and second in order to have a "ball radiused" corner!

Think about it!

Calling out "all around surface" on any surface, will do the job, but I am seeking a more elegant method or one using symbols rather than text.

 

[microdesign]

I am thinking I should call out "SR.xxx" for spherical radius. That seems like the simplest.

Anyone have a better plan?

 

[ewh]

Micro,
You are correct. I was approaching it from a modeling standpoint, where it would normally be the resultant. You could specify "4X SR.XX" in addition to the "6X R.XX" callout and you would be covered.

 

[Heckler]

I second ewh, spherical radius would be an appropriate callout for a ball radius corner

 

[wgchere]

Thanks EWH, but no sir! Assuming the same radius dimension on each edge, radiusing each of 3 edges leading to a corner will NOT cause the corner to be fully rounded! The "shank diameter" of the radius cutter must follow the radius of the third edge radius while cutting the first and second in order to have a "ball radiused" corner!

Think about it!

Give your machinist some credit! If you call out 4X R.XX on the top view (to cover the vertical edges of your cube) and callout R.XX with the "all around" symbol on the front or side view, do you really think your machinist is such a bonehead that he won't understand that you want a SR on the corners and do the verticals first?

Think about it! ;-)

 

[microdesign]

I admit that I can think of no reason not to have SR corners, but if there is no instruction to do it, and if $100K of parts are made and finished without SR corners, guess who eats the pointy-soft cornered parts?

 

[wgchere]

They do, if you did not detail, callout, or in any other way indicate that it should be other than as drawn. ASME Y14.5-1994 discusses the "implied drafting" clause--if it looks like it is 90°, it is 90°, if it appears to be on the centerline it is on the centerline. If it appears to be a SR it is a SR.

But it probably wouldn't hurt to CYA and call out a ref SR (4X SR).

Merry Christmas all!

 

[microdesign]

Drawn orthographically, there will be no view conclusively showing it to be SR!

 

[ctopher]

I don't know what your part looks like, but however you do the R callout, make sure it is clear for ANY machinist to make the part.
4X R .XXX or SR .XXX will work, depending on the design.

Chris
Systems Analyst
SolidWorks/PDMWorks 05
AutoCAD 05
ctopher's home site (updated 06-21-05)
FAQ559-1100
FAQ559-716

 

[markn82]

I used to be a machinist. If you don't specify a Spherical Radius, you aren't going to get a spherical radius.

 

[ctopher]

... or if you don't care "Shape Opt".

Chris
Systems Analyst
SolidWorks/PDMWorks 05
AutoCAD 05
ctopher's home site (updated 06-21-05)
FAQ559-1100
FAQ559-716

 

[wgchere]

I used to be a machinist. If you don't specify a Spherical Radius, you aren't going to get a spherical radius.

Well. I stand corrected. That's what's great about this forum--always something more to learn.

 

[microdesign]

We agree! A great forum! Not as good as my babe of the day forum though!

Thanks for all the answers, even the wrong ones!

Davin

 

[sprintcar]

sure... don't post the "babe" forum link... don't we get Anything for christmas in here???

"If A equals success, then the formula is: A = X + Y + Z, X is work. Y is play. Z is keep your mouth shut."
-- by Albert Einstein

 

[microdesign]

My favorite BOTD forum is on Apriliaforum.com, but you have to be a member. Feel free to join, and free to buy an Aprilia too ( not required)!

Here is another from Portugal:

http://gajasnuas.blogs.sapo.pt/

Enjoy!

 

[microdesign]

For a rectangular solid object with spherical radiuses on all corners, and edge radiuses on all edges, I have decided that the proper callouts are:

4X SR.XXX on the top face

4X SR.XXX on the bottom face

4X R.XXX on the front face

4X R.XXX on a side face

The other 4 edge radiuses are defined by the SR callouts.

No surface of all around symbols are required for this.

Additionally (on some other parts) I have some SR centers falling outside the part boundary, and near other center marks. For these I have dimensioned the centers, and drawn a dashed circle of equal radius on the SR center.

It looks clear and good and right. I think ANSI should adopt it!