Hi All,
I have been running into some problems with overseas manufacturers and CAD files. I do my work in solidworks and it seems manufacturers are using every CAD package differently. How do other transfer files to manufacturers? Do people prefer stp.iges, stl?
Thanks any insights or tips are helpful
mark
The answer is to work in the same CAD package as your manufacturer. Pro E is a pretty much defacto Asian standard these days, but Solidworks is also very common.
You should not use STP, IGES, and certainly not STL (which is a tessellated rapid prototyping part) unless all other means have failed. All of these formats usually involve some level of “recalculation” which can corrupt or modify data in a way that you did not intend.
We’re seeing just as much SolidWorks as ProE these days, so we most often send files in SLDASM, SLDPRT and .x_t
I agree with cyberdemon - try not to STP, IGES or STL files (or even offer to) unless it’s a last resort, but beware; the files become dumb solids at that point and are next to useless.
Ok thank you both. I have been zipping my assemblies which is my preferred way of doing things . Do you send via email or FTP?
Thanks
.zip (or more commonly with the Far East .rar) is what we do as well. A few clients will have their own FTP (we always ask) and it’s easy to map a drive to their FTP for consistent back-and-forth, but email transmission is becoming more common - although we don’t prefer it.
I have to say, that I simply don’t get the negative comments with respects to STEP files.
For me, they make a lot of sense. I rarely have seen any translation problems of STEP files, especially if it is between like systems (e.g. Pro/e to Pro/e).
They also reduce risks of alteration errors. If you’re sending your files out to someone to manufacture you simply do NOT want them making alterations to your files. The good old fashioned “oh, we just need to increase that hole for clearance tolerance by .5 of a mm” more often than not does not make it back into the original file database.
By driving the manufacturer to use non-modifiable files, it forces everyone to be on spec. It holds me responsible for making sure the dimensions and specs are correct, and it holds the vendor responsible for machining it properly.
@ ip_wirelessly
thanks for the input, is step file the common go to file type for you when sending CAD files to manufacturers? Do they ever have issues with these files?
Thanks so much it has been such a hassle trying to find a good go to format that works for most jobs.
Thanks again to everyone for the invaluable input
First of all: ask what they prefer. Here’s what it usually looks like for us:
Tool makers in Asia: STEP. zip, rar, ftp, email, dropbox, skype whatever… as long as they get the file. Just accompany it with a dimensioned 2D drawing. I prefer zip (no extra software needed) and email (foolproof track record).
When we use an external ID agency they use Rhino. The STEP files they send never work well for some reason, IGES imports better (into SW)
3d printing vendor: Parasolid (.x_t)
Before we used STEP and there were some knitting problems. Solidworks can export 2 different STEP extensions, the second one works better for some reason so I always use that one, but I have no idea what the difference is. I think it’s called STEP214, and the other one is 212 or something.
Also I don’t see why you would care about a format that works for most jobs. You still have your native file, just export an up to date version in any format when you need it…
I wouldn’t call a dumb solid next to useless, in fact I agree with IP in that a dumb solid is precisely what a manufacturer should have. Not that anything is stopping them to remodel it (which they do)… but if anything is not according to my dumb solid I can point to it and say so.
engio is correct, get to know your vendor(s).
I have had almost no problem with STEP. But, reality being what it is, there are setting within every translation system to tune to the needs of the task at hand,etc.
I’ve spent countless hours in the past (the 90s were hell for this) trying to get clean files for transfer. But we seem to be reaching the point of “good enough” on this stuff. I rarely have to go back and forth with my vendor. If I do, it tends to be an error on my side.
I wouldn’t say it’s STP hatin’ - STEPs for many systems work fine.
From the Pro E side, you can always export a Neutral file that is featureless if you do not want a vendor monkeying with geometry.
With that said, even with a step file I could easily bring it into my CAD tool, offset some surfaces, monkey with it, etc. This is EXACTLY what happens when you send any file to a model maker. They need to make changes, and it doesn’t matter what format you send, they’ll do what is needed to tweak it.
Data exchange is a non-trival process, and even within the corporate realm where we should all be on the same system and tolerances I’ve seen first hand what happens when vendor 1 uses a different set of tolerances from vendor 2 and data gets crapped up in the process.
As long as you (Point A) and whoever is at Point B are using the same data, all is well. But I can recall multiple first hand experiences where 99/100 IGES files (our old method of transfer) would be perfect, and 1/100 times when a surface was rebuilt by the software, washed out a subtle design detail, and the part almost went to tooling before we noticed.
Fair points and agreed on all fronts.
I guess the core message is that no matter how you slice it, you need to be diligent in managing your data. No matter what the format is.
Just want to make sure the readers out there know that there is some agreement to the details of data exchange and disagreement to the message that you should default to protecting your data’s design integrity.
If the project is my own property where we are the designers and the manufacturer, I do all that is necessary to make sure our data remains in our control all the way to shooting parts/assembly, etc, but…if the project is for a client, please know that you risk losing that client if you become Mr-or-Mrs-ego-designer and intentionally send data that is not editable when better options might be at your disposal. When my company is acting as the industrial design, CAD and engineering functions of a client’s team, I do my best to make our actions as efficient and compatible as possible. We check the egos at the door, unless you’re a paying client, then you can exhibit all the ego you want as long as your check cashes. 
We once had a client confirm they had SolidWorks native data as a starting point for our work - three weeks later, after multiple iterations to a proposal, we started the project…only to find they’d STEP’d data into SolidWorks and sent it to us as native. Like we wouldn’t know…
Some companies use STEP files, etc. as built in customer retention tools. I know of several that do this with mech/id CAD data as well as schematics and electrical. They, effectively, hold their clients’ data hostage.
Good for the short term bottom line, I suppose. But the bitching and moaning I hear about this from prospective clients is far from insignificant. People know, and don’t like, it when you hold their data hostage.
In some cases a file without the parametricy makes sense, but in my experience its much easier to give them the native file and try and keep tabs. If they are going to make the changes, they will.
They key is to know what software they really need. On one occasion we were told that the vendor needed SolidWorks so we built the whole thing in SW. But they were really using Pro/E (which we would have gladly used), so when they got the files they got a viewer, took SCREENSHOTS and rebuilt the whole thing from scratch!!
They then sent the data back to us to check and we saw that every surface was just a little bit different. It was a mess. Like roadkill. A clean rebuild in Pro/E was the kindest way to put the poor tortured design out of its misery.
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