Fabrication Drawings With Full Detail

[weaston]

When creating drawings for fabricated (welded) items, what is the industry standard? Should there only be one drawing for the fabricated item inclusive of all required detail or should we create multiple drawings detailing each part which the fabrication consists of.

I think we should create one drawing with all required detail, however, our management wants individual drawings.

How can we convince them that it would be better to create only one drawing for fabricated items??

[RICHARD ZASTROW]

The method I'm most familiar with is seperate drawings for individual components, though I have seen large drawings with details also on the same drawing.

The large drawings were often damaged or burned as they moved through various operations. To keep the product progressing along required making more copies of the large prints.

I personally prefer individual detail drawings with a bill of material for the assembly for the above reason. Maybe your management agrees.

[JerryFlyGuy]

I think it depends on what your people want. I like having drawings w/ only one part per page, possibly showing several views of various fab steps. However, it is the mandate of the company I work for to minimize paper and complexity of drawings. Therefore I'm forced to do drawings w/ several parts per page and it does make it more difficult from a tracking and drawing layout perspective.

Anyway, either will work.. some sometimes it's a combo of both.. It's much easier to organize large projects when there is one part per page.. and you can publish a drawing binder and let the fabricators pull the drawings only they need.. saves sorting through lots of pages to find a detail.. I've got lots of job's where there are 100+ pages of drawings. It's not a simple job to make the drawings "flow" so fabricators can find parts. Having drawing numbers which duplicate as part numbers elliminates this problem, but forces the need for single part drawings.

As always, everything is a compromise..

[low_48]

I've been in one engineering career position or another for 24 years. We've always made individual drawings of the piece parts and then assembly drawings. For really simple parts I guess one drawing would work. If there is machining needed, all the tolerances and geometric tolerances would really make a confusing drawing. We do have machining on a welded assembly and those dimensions are called out on that drawing. We have 3 levels of drawings here; the group drawing that shows all the parts, bolts, washers, etc.... that make up a major component, assembly drawings that show how to weld and machine that weldment, and the lowest level piece parts. It's worked for over 75 years here.

[MDLang]

Definitely separate drawings for each part and an assembly drawing for the assembled unit.

There is usually too much detail to cram all the required info into one drawing. I have occasionally worked with drawings that had partly assembled views only and I think it's a royal pain.

If the parts are simple then you can put a couple related parts per page for example a left and right hand part. That way your likely dealing with similar tolerances and features so it helps avoid the confusion and mistakes that comes with plastering parts on a drawing willy nilly.

Mike

[bigbunny5]

Weaston:
I've been doing Mechanical Drafting and illustration for the better part of 20 Years,and I can tell you The absolute UNQUESTIONABLE industry standard For Drawings is what ever management wants!!!! Now when you are dealing with Military Contracts, you have to abide by their standards. If you were an ISO 9000 Company, it would be up to you ISO Officer to set "Standard". In Drafting there are no fast and hard rules on stuff like this, it's all up to company management, after all at the end of the day they do put food on your table, WHO ARE YOU to question their wants ?

[Charlie Gary]

The more you pack onto one piece of paper, the more the cost of manufacturing the parts increases. JerryFlyGuy has a bad scene with being told to both reduce the complexity of the drawings AND put more stuff on one piece of paper.
When you put more stuff on a drawing, you increase the amount of time the person making the part(s) has to devote to figuring out how to build it, and not the other stuff on the drawing. If there's only one part to build it's OK, but if it's a production part that time is added every time the parts are built. This is where you have to find out if the extra time spent generating drawings will save time on the shop floor.

[Charlie Gary]

echo deleted

[nazar]

if your fabrication work has a lot of individual parts, i think you should make individual part drawing as well as final assembly drawing.