Thanks for the reply, but this mostly shows examples of notes and proper dimensioning for controlling a casting. I am particularly interested in the machining drawing used after the casting is already accepted.
I don't know of a standard for this.
I wouldn't create a special drawing for this exercise.
Then again, I might not fully grasp what you're trying to accomplish.
If you think in simplistic terms, "modifications to an existing part" means revision roll (if you're modifying a part then by definition it's no longer what it once was). You can certainly highlight the changes in revised drawing by referencing the sheet number and border zone of the features that are affected.
And if it's not backward compatible then p/n change.
The multiple dash being on same drawing (p/n) muddies the water a bit.
The revised drawing (e.g Rev B) is what's used to modify the existing part (e.g Rev A).
Thans for the response, Kenneth.
I suppose I wasn't clear enough. We have a casting drawing. Then, a later operation is to have that casting machined. So both are active drawings.
We purchase the casting from an outside vendor, and our inspection uses our casting drawing to make sure the component meets the dimensional requirements of our casting drawing. Then the component is machined, and our inspection uses our machining drawing to make sure the dimensional requirements of the machining operations are met.
So no drawings are revised, they are both initial release drawings.
casting = unique p/n
machined = unique p/n
think of it from purchasing point of view.
you bought a part (cast) then inspect and receive it.
that p/n is finished.
in our plm system this would be represented as an assembly.
i'm guessing you don't want to hear that though.
this is one of those rare instances where i would use a configuration in a part.
in solidworks i would use the weldment feature.
as welded = as cast
as machined = as machined
one model with 2 drawings
i think it's better to keep the two processes separated.
Message was edited by: Kenneth Barrentine
And show the casting p/n as the raw material for the machined p/n.
I agree with Wayne.... The casting drawing is the raw material for the machined drawing. Both documents stand independently on their own. The casting part number could be used for several different machined part numbers.
KISS works real well here.
Thank you all for your replies.
How would this drawing appear?
1. MATERIAL: CASTING XXXX-X.
Then, in the part table:
YYYYY-Y This is a machining of a casting See Note 1 Material Specification Here Anodize per XXX Part Number Description Material Specification Finish
Any further comments; do you agree?
That's pretty much how we do it at my company, Charles. All of our detail drawings have BOMs but without the quantity, item, and descripiton columns. Each part number (dash number) gets its own row in the BOM. The only difference from your machined example is we put the casting / forging / extrusion part number into the material column instead of in a general note.
Alternatively, we will add a "Make From" column to the detail BOM, add the casting / forging / extrusion part to that column. Then the Material column will reference in parenthesis the material that the casting / forging / extrusion is made from. This is useful when the higher up assemblies need to show the finish machined part's actual material instead of the part number it was made from.
All the drawings I've seen have a bill of materials listing the casting as a sub-component or a note saying make from XXXXXXX.
ASME Y14.24-1999 Fig 11 shows an Altered Item Drawing (Mechanical Alteration). The example shows the part in its final form with several dimensions added and a flag note which states "ALTERED FEATURES". It also calls out the finish and coating of the faces created by the alterations, and the usual deburr note. The example doesn't mention the source component, but I think that is just an oversight.
An Altered Item Drawing shall not be prepared to modify an existing item that was developed by the design activity.
That is me. I "shall not" prepare an alterered item drawing for something that was developed by myself. I'm on board with the above suggestions to say that the casting is a raw material. That is how our ERP system manages it, too.
Yup, I think your safe with that bet. I used to create Make-from drawings which called out the source part as the material for the make-from part.
It appears that altered items drawing was intended for modification of purchased/received parts (like if you need to modify a bolt, as in the example), but not for mistakes. Routed parts (parts routed to have multiple processes applied in order to get the final product) do not appear to be a consideration in ASME Y14.24.