Drawing finish question

[frankml]

Hi all,

Just looking for some input on how other companies handle coatings and such on parts.

I made a drawing for a sheet metal panel that needs to be irridited and subsequently powder coated.

Say you were having one shop fabricate the panel and another irridite and powder coat it.

Would you...
A) Send the one complete drawing, which includes the pertinent finish information, for the part and ask the fabricator to quote just the unfinished part and submit a PO for said RFQ. Then send it to the plater asking for a quote for the irriditing and powder coat and send them the parts and a PO?

OR

B) Create a drawing for the unfinished part. Then create another drawing with another unique dwg number for the irridite process for that particular part, and yet another for the powder coating of that same part, again with a unique number. So, if down the road you want one shop to perform all three processes, you would send them 3 drawings for the same part. And of course the two finishing drawings would need to reference the original unfinished part drawing. Also if you revise the original drawing you would need to revise the 2 subsequent irridite and powder coat drawings.

Just curious to hear your thoughts...

This is not a joke.

Thanks,
FrankML

 

[hydtools]

My first reaction would be to separate them. Then it does not confuse the process of requesting a quote from the fabricator. And it allows you to easily change colors or provide parts with different colors, if that becomes necessary.

I assume you do not have a CAD system that updates assemblies when a component part is changed. You commented about having to change the coating drawing when the uncoated part is revised.

If you change to a vendor that can fabricate and coat the part, just send all drawings for the request for quote.

Ted

 

[handleman]

I guess it depends on how "formalized" and/or "hands-off" your quoting/ordering process is. And maybe whether you are doing product design or one-off, etc. Unless there are very specific instructions on how to paint/irridite/powder coat (masked areas, etc), I don't see the benefit of a drawing. If you must make it a different part number, just tabulate it on the one drawing.

-handleman, CSWP (The new, easy test)

 

[frankml]

Thank you for the replies.

As the color is the same as all of our other parts, I can't say there would be an instance where the color would change.

I love the idea of tabulating it on the drawing, or even using a suffix such as -00 = nofinish -01 = irridite -02 = paint, however the powers that be mandate a part number can only be 5 digits + R + the revision number... e.g. 90210R1
This is to ensure compatibility with shops that use computers from 1982.

It just seemed like a waste of time to me and wanted some other opinions. As far as updating, everything is kept as a hard copy in a manila folder, so each time they would all need pulled and changed, even though the anticipated change of color is unexpected.

The purchase orders are done manually in WORD. and each one goes in its own manila folder. Also to keep from having to open the PO folder, the "powers that be" have the secretary hand write the items on the PO on the outside of the folder in pen. I suggested folders with clear fronts, but they cost more than having someone hand write on the front I guess. I also suggested printing the PO on a label and sticking it to the front of the folder, and that was shot down...

The part numbers are also kept in a composition notebook, written in ink. This is to prevent two people from using the same part number, you have to manually go get the notebook to get the next part number.

Regards,
FrankML (aka FML)

 

[Tunalover]

Don't let the process dictate how you do your drawings. This is a trap that a lot of people fall into. Have a single drawing calling out all processes regardless of how many sources it takes to make it. If you can't get a single source to sell you the part then write POs with line items calling out what is needed. Make the system work for the drawing not the other way around! Of course every rule has an exception.


Tunalover

 

[hydtools]

Having a single composition notebook for recording part numbers is a good thing. The basis for a form of document control.

Having vendors stuck in the past with computers with software that cannot handle long file names is not a good thing. You or 'the powers that be' are allowing your vendors to structure your business instead of the other way around.

Once you start using significant part numbers, base numbers with suffixes, you might as well just assign non-significant part numbers. A number is a number. If you use significant numbers, be sure to create a code table to define the significant number sequence.

Ted

 

[drawoh]

frankml,

I specify finishes like Iridite on the fabrication drawing. We don't change this information, and the instructions usually are simple.

I prefer separate fabrication and paint drawings. You have the option of sending both drawings to one fabricator, or sending out for fabrication, then sending the fabricated part for paint. You have the option of creating a new paint drawing or tabulating the existing drawing with a different colour.

If you have a procurement process in which you order stuff, receive it then send it out for more work, you need part numbers for each stage, starting with your unpainted part. Each colour requires a different part number.

A long time ago, I set up a drawing list in plain text. I set up scripts that wrote a lock file, then launched the drawing list in a text editor. The whole thing worked from UNIX servers as well as from Windows.

Microsoft Word only allows one person access at a time. This would allow you to maintain a network accessible drawing list as long as everyone is on the same version of Word.

JHG

 

[frankml]

Thank all of you for your input.

At least it is friday. :>)

Take care all,
FrankML

 

[dgallup]

We do this with tabulated drawings. The drawing number is something like 1234-5678. The unpainted part is 1234-5678U, the painted part is 1234-5678P. We do the same thing for all outside processes like heat treating, plating, etc. One part number suffix when it goes out, a new part number suffix to receive it back in.

We have some tabulated drawings for items like o-rings where the suffixes go from A to ZZ because of the number of instances. It is very easy to find the right drawing. That is not the case if you start giving completely new part numbers to each instance.

 

[frankml]

Dgallup,

I agree. It makes it intuitive and over time increases efficiency.

I did something similar for assembly dwgs, I made them start with A, i.e. A1005R1. This way you can tell it is an assembly dwg. One would think that would be enough...
However I was chastised because I left ASSY out of the file name, which indicates it was an assembly. Even though the A prefix already tells you that.

WRONG FILENAME:
A1005R1-WIDGET_ROUND_1000_2500_0250_PLASTIC_NYLON_WHITE

RIGHT FILENAME:
A1005R1-ASSY_WIDGET_ROUND_1000_2500_0250_PLASTIC_NYLON_WHITE

The ASSY reaffirms it is an assembly, just in case the big A in front didn't give it away. All part numbers must be less than 8 characters, but file names(aka, extended part descriptions) can be up to 256 characters long.

My whole point was to avoid the following...
20765R1 - Base Part Unfinished
20854R1 - Same Part With Irriditing (references 20765R1)
20947R1 - Same Part Already Irridited With Purple Paint (references 20854R1)
20989R1 - Same Part Already Irridited With Blue Paint (references 20854R1)

Now if I revise 20765R1, I have to revise the subsequent dwgs to reference the proper base and irridited part, granted the finishing drawings could reference the base part number without revision, but that wouldn't fly.

Oh well...

Almost quitting time...
FrankML

 

[frankml]

"We have some tabulated drawings for items like o-rings where the suffixes go from A to ZZ because of the number of instances. It is very easy to find the right drawing. That is not the case if you start giving completely new part numbers to each instance."

We tried tabulated drawings for a part that had the same ID, OD, etc. but the OAL varied.

Well the guy in purchasing forgot the suffix and the shop picked one of the lengths from the table instead of contacting us. From that point on, each length needed it's own part drawing and number. Meaning if there were 15 different lengths and the ID changed, you would have to rev 15 drawings instead of 1. All because a guy left off a suffix and making unique dwgs for each instance was the best way to solve this issue?

Regards,
FrankML <- Livin' The Dream

 

[Ron]

Why not have the fabricator responsible for the coating as well...even if he subcontracts the coating to someone else, he bears direct line responsibility to you...keeps the separate subcontractors (vendors) from pointing fingers at each other and leaving you out in the cold in the event of a problem.

Yes...one drawing should have all the info on it. Too much chance of leaving something important off one of the parsed drawings.

 

[KENAT]

I'd rather have the fabricator take care of subbing out the plating, what we normally do, as well.

Means you can say things like 'DIMENSIONS APPLY AFTER PLATING' etc.

Separate docs is arguably more robust, but has disadvantages.

If at all possible I'd stick with single drawing.

"dash" numbers on the same drawing might work.

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