Guidelines for Ballooning Characteristics

[Springhill]

Hi there, new to the forums.

My company is new to ballooning drawings (I'm new to the manufacturing industry) and I had a few questions about my procedures for the community:

When the customer specifies a quantity before a dimension, 4X Dia .28 in, call it dim 10. I check and record each feature covered by that callout for our IPCs and the FAI. I don't list the sub-balloons 10.1, 10.2, 10.3, 10.4 on the drawing unless asked or I feel that the dimension is critical enough to warrant it being explicitly listed.

If the dimension is labeled as typical, R.25 in TYP, call it dim 11. I check all the features I can find on the FAI that fall under that TYP note but only record on the FAI the most off-nominal actual.

Is this a reasonable approach? Or should I be more explicit with my sub-ballooning and count and record all typical? In some cases, its dozens of dimensions that fall under the one callout.

The machinist suggested putting a reference quantity before, 22X (12), or in the balloon, (22X 12) to indicate the actual number of dimensions on the part that are covered by the typical.

Has anyone experimented with internal notes like this on the client facing ballooned drawings? I do not see any rules saying we can't do this.

 

[Michael_M]

I have done it both ways depending on how the customer wants it. Some customers (AS9102) want each dimension listed separately so I bubbled the print (for example, 22) and on the FAIR form, I put 22a, 22b, 22c, etc. Other customers (also AS9102) want the range dimension so for item 22 the report would show .101/.104 with the dimensional range falling withing .101 to .104 regardless of how many specific items.

To keep my sanity, I started reporting items with X (4x for example) as a, b, c, d (for example, 22a, 22b, 22c, 22d) and items that are listed as typical as a range (for example .101/.104). I had not received any push back from companies since I changed to this method.

 

[Miner]

This table is from Lockheed Martin's First Article Inspection Guidebook. The Item No. refers to the number on the ballooned drawing. They list the number of times the requirement applies (i.e., 8x) then list the minimum and maximum values under Results. BTW, it is good practice to start numbering in the upper left then proceed clockwise around the drawing.

Ultimately, it will be up to your customer as there does not appear to be a standard for this.

 

[Springhill]

Ok so what I see in that document is that Lockheed accepts individual dimensions with a multiplier (8x) listed in a single box separated by commas or a range, given as XX.XX/XX.XX. There is nothing in there about the typical dimensions, so I would assume in lieu of information a XX.XX/XX.XX would be acceptable. I would rather not list a #X multipler for a typical if I don't have to.

There is no sub-ballooning on their drawings, I guess it's more important to them that the dim is checked and was in tolerance then dimension accountability to each individual feature.

Something that is also interesting is the reporting of the basic dimensions, which I thought technically does not have its own tolerance besides the geometric tolerances. I think I saw a geotol video awhile back where he didn't record the basics on the inspection report. (I record basic dimensions using the tolerances from the title blocks, clients seem to like it).

I'm surprised there isn't a proper standard for ballooning, it's really up to the client.

Thanks for the input, Miner and Michael_M!

 

[Miner]

I would agree with your approach to typical dimensions. I was surprised about the basic dimensions as well because they should be part of the callout (e.g., position), and you would report the position result, not the X and Y coordinates.

 

[Kurt Smith]

When I am asked to make these reports, I'm often required to include extra details that honestly shouldn't be included. It really depends on the customer and how familiar they are with both the parts and process. (One of my more frequent customers who require reports don't themselves understand the drawings. So, to cover their butts with the final customer, they require me to report on every drawing detail. Basic or otherwise.)

It's common to have the situation you describe where they want diameter and position for multiple holes, but they all share a callout. So I report them as 10-1, 10-2, 10-3, and 10-4. I do that both on the report itself and on the drawing so its clear which hole is referenced if one hole is closer to tolerance than another.

Another factor you might run into is how many parts are being reported at once. The form my customer requires doesn't separate the parts being checked, but they want 5 parts reported at once. So I need something to separate the 4 holes because there will be 20 total measurements reported for callout 10.

 

[Springhill]

"One of my more frequent customers who require reports don't themselves understand the drawing"- I feel that.

Interesting thing about reporting multiple parts on one report, have not done that yet. If my parts are serialized and I am required to 100% inspect and report, each part will get its own report.

 

[Kurt Smith]

"One of my more frequent customers who require reports don't themselves understand the drawing"- I feel that.

Interesting thing about reporting multiple parts on one report, have not done that yet. If my parts are serialized and I am required to 100% inspect and report, each part will get its own report.

Our parts aren't serialized. They want PPAPs done for these parts but aren't ordering enough volume to actually do it properly. So, our compromise was full detail reports on 5 parts of the first batch. I wanted to use a format that set individual columns for each part inspected. I was instructed to use a format they provided. The results were... usable, but not recommended.

 

[Ron Rompen]

Miner, I have to ask - why are you reporting the 'actual' measurement of a BASIC dimension? A basic dimension is a theoretical entity, used to define a characteristic. I have been required to include BASIC dimensions on a report in the past, and have always just entered the 'target' dimension.

 

[Miner]

Miner, I have to ask - why are you reporting the 'actual' measurement of a BASIC dimension? A basic dimension is a theoretical entity, used to define a characteristic. I have been required to include BASIC dimensions on a report in the past, and have always just entered the 'target' dimension.

I am not. That picture was from a Lockheed Martin FAI guidebook. I would only report the Position result as I stated in post 5.