ISO Hole Table Format & Radius Callout

[Jieve]

Hello Again,

Taking a short GD&T break after my 100 GD&T question posts, I have a few slightly more general ISO format questions.

1) Despite my CAD software being set to ISO standard, it enjoys regularly using ANSI standards for certain things (such as projection angle, hole callouts, etc.). I have a part drawing with a hole table created by the software. Each hole has a letter label corresponding to the size, and a number corresponding to the instance. In other words, if I have 4x 10mm holes, the 3rd hole would be A3. If I have 6x 5mm holes, the label may be B5 for a certain 5mm hole. This is quite easy to read, but in the older DIN standard I'm referencing, it is done differently. Each hole is given a number, and if there are multiple coordinate systems, another number is given to the coordinate system. In other words hole 6 in coordinate system 2 would be designated 2.6. What is the correct ISO way to describe these holes?

2) Along with holes in the table, I would like to include a number of slots as well. I have read (I believe referencing ANSI, although I may be wrong) that the centroid of the slot is used as the coordinate, and the maximum slot size is given in the hole table under size, for example 21x9. In another case, I read that one should use the center point of the hole closest to the coordinate origin. What is actually the correct way to include slots in a hole table using the ISO standards?

3) Finally, I have a flat plate which will have a complex series of ribs CNC milled into the bottom. The bases of the ribs are radiused into the plate, which will be done with an 8mm diameter ball end mill. I have not shown these radii in the ordinate dimensioned bottom view of the plate which details all of the rib coordinates for the CNC. However, on a separate sheet, I have included top, bottom, front and side views which include these radii in the views, and have simply added a 4mm radius in the front view. Does this sound like it is clear enough from the way I have dimensioned it that all ribs should be radiused into the plate, or would it be a good idea to add a note somewhere else saying "all ribs radiused 4mm into plate" or something like this? Or is there maybe a better more common way to do this?

Thanks!

 

[fcsuper]

Sorry for not answering these questions, but just offering some advice. You may wish to turn each one of these questions into their own forum postings. It makes it easier to respond.

Matt Lorono, CSWP
Product Definition Specialist, DS SolidWorks Corp
Personal sites:
Lorono's SolidWorks Resources & SolidWorks Legion

 

[Jieve]

Hello,

anyone by any chance have any answers to my above questions? If not, I'll just use the slot center in the hole table and leave the designations as they are, and let the machinists come up and ask me what I was thinking .

Thanks!

 

[pmarc]

Jieve,
The only ISO standard I can think of right now is ISO 129-1:2004. There are some methods in there regarding use of tabulated coordinate dimensioning for round holes, but probably nothing interesting for slot-like features. Actually the DIN method you described is also there. (No wonder, since ISO and DIN GD&T standards are strongly correlated.)

But this does not mean you cannot do it in a way you described. If I were you, I would simply add an extra view on the print showing what exactly the center of the slot is (how it should be interpreted), and then state somehow in the chart that the locational dimensions apply to that center. I think it would be clear enough and would not violate any higher precedence dimensioning rule.

Regarding point 3, I must admit that a picture (at least simplified) would really help. I think I can imagine those radiuses but would like to be 100% sure what we are talking about.

 

[Jieve]

Thanks pmarc.

I did exactly what you said On the drawing regarding the slots and made a Note that all coordinates are to the center of the slot. In the table, i also relabeled the holes with integers as opposed to a1, a2 because it seemed to me to be more inline with the din/iso standard.

Regarding the radiuses, I showed a view of the underside of the plate and made a Note with a leader calling out that all radiuses On the underside should be 4mm. It seems quite clear On the drawing now, unfortunately i don't have access to my Software at the moment so cannot post a pic. However i'm sure if there are misunderstandings I'll hear it from the machinists.

Thanks!