FEELER: what do you guys think about sharing parts libraries?

Since I have begun to source parts for my first pcb, as you could imagine I have no part library for many parts we normally use in our builds. Consequently I am having to build them from scratch off of datasheets, just like those who have come before me.

Has anyone thought to build a "prodigy-pro official parts library" or "51x alliance parts library"? one that could be added to and modified like a 'creative commons' piece of software?

Not only would it reduce the chance for errors in part creation for new people like me, it could be used as a learning tool to xref my own part creations, collective use would reveal errors early in part submission and folks could fix them in real time and submit updates, and parts that have been used on tried and true pcb's out there in the retail world would help build confidence for folks getting into pcb production for the first time, and yes, certainly it would be time saving for the initiate.

Are parts libraries something to guard like a gerber? Isn't there a .lib standardization or conversion utility for people who use different pcb programs? What's the general attitude concerning these? I ask because I am surprised there isn't something like this already pooled around here. What do you think?

EDIT: I now realize this question would probably be better recieved in the "drawing board" thread, but I wanted to see what people thought shooting from the brewery hip...

good question -- however, one of my major sources of frustration when getting boards made is when I've used someone else's libraries...



I have found that Sparkfun's collection is quite good. Fewer errors there.

major sources of frustration when getting boards made is when I've used someone else's libraries...

Click to expand...

Sure, I understand. Is that becuse the parts don't fit with the datasheets or is it because you like to customize? I imagine the library could be based on standards and modified to suit. You could even have modified parts with a extension on the end  

tx.001.2234.std
tx.001.2334.rochey.churchill

it's more about how you intend to assemble the board etc.

some folks do the minimum pad lengths, some do the longest. (longest is easier to hand solder, minimum gets you tighter pcb density).

there's other stuff too, like autorouter keepouts, silkscreen layers, center of the device (for pick place),

Creating and managing layout libraries is not simple stuff if they are to be shared. Some companies hire component engineers who's job it is in life to create the libraries and make sure that they are done to company standards. Without a "librarian" - things get messy REAL quick.

Boji, 95% of the stuff I use came from Eagle stock libraries or downloaded from Eagle website library.
The other 5% I created on my own.

But regardless if you created your own, or used parts by others, you must verify them all by yourself. 

You can't just plop a part down on your CAD screen and send it off for manufacturing and hope it works.

For library parts I create myself, I buy the part beforehand so I can measure with a digital caliper. I do lots of printouts and lay the actual part on top of the printout to see if it fits. If mechanical drawings are available for the part, I consult it and verify that my real-world measurements come close or is the same as the "official" drawings. 

minimum pad lengths, some do the longest

Click to expand...

Sure pads can be adjusted to size once imported, however pin to pin center dims would be mostly consistant no? I mean there's a min/max for everything. The standard lib would be roughly the mean avg.

Without a "librarian" - things get messy REAL quick.

Click to expand...

I actually internned for a short while with a company in this very position.
It was a lot of web surfing for datasheets and confirmng pin dims.
When a part had thermal sensitivities (the geeks were developing a DWDM switch that would send light full duplex thru one fiber optic cable) I just had to overlay keepouts on the part. I never did any placement or work on the actual boards. 

Creating and managing layout libraries is not simple

Click to expand...

It can be as difficulty or as easy as we want it to be, really. If Eagle has as Owel says, 95% of the parts already created, well then, perhaps a Prodigy DIY library would not be very useful.

you must verify them all by yourself

Click to expand...

This I don't understand. I mean I understand due diligence and wanting things right the first time, but if Joe uses a TX not found in a eagle library, and Jim wants to use the same part, it still seems that a mutual library between them would be benefit them both over time, assuming they both contribute to it.

You can't just plop a part down on your CAD screen and send it off for manufacturing and hope it works.

Click to expand...

Not in our lifetime.

I buy the part beforehand so I can measure with a digital caliper.

Click to expand...

I just have this dark vision of thousands of DIY-ers all over the world, at slightly different points in time, at their benches under lamplights, all measuring the dimensions of a part they all got from the same manufacturer's batch in a unceasing pageantry of parallel discovery. =P

I just have this dark vision of thousands of DIY-ers all over the world, at slightly different points in time, at their benches under lamplights, all measuring the dimensions of a part they all got from the same manufacturer's batch in a unceasing pageantry of parallel discovery. =P

Click to expand...

;D

Isn't that what we do for fun?

There are industry standards:
http://www.pcbmatrix.com/Products/lpsoftware/lpviewer/

Of course, like Rochey said, there are at least 3 main standards, small, medium and large footprints for almost every part. 

I expect the trend where parts sellers, and contract manufacturers are partnering with or providing PCB cad software, suggests that connection (component sellers) could be exploited to integrate footprints for any parts they sell seamlessly into the supported design software.

Of course easier to say than do... and the vendor doing all that work, isn't guaranteed the parts sale so cost recapture isn't certain. 

JR

boji said:

Has anyone thought to build a "prodigy-pro official parts library" or "51x alliance parts library"? one that could be added to and modified like a 'creative commons' piece of software?

Are parts libraries something to guard like a gerber? Isn't there a .lib standardization or conversion utility for people who use different pcb programs? What's the general attitude concerning these? I ask because I am surprised there isn't something like this already pooled around here. What do you think?

Click to expand...

Sharing parts libraries between different ECAD tools is basically impossible. Sure, Tool X might have a program that converts Tool Y's libraries but these are often problematic, and you might as well not even bother. Nothing is standardized. You'll end up spending more time vetting the conversion than you'd spend actually creating the new library parts.

One thing to consider is that some people (especially those of us used to a professional design environment) want the schematic symbols to include information that simplifies BOM generation. This can mean either a full orderable part number (say, "SN74LV595AD" instead of "595"), or perhaps a "company part number" that can be used in a database lookup to derive an orderable part number. For a simple 10-part board, it might be reasonable to print a list of generic part numbers and look up orderable numbers by hand. For anything more complicated, forget it. BOM generation needs to be automated.

-a

Thanks for the replies, suggestions, and links everybody.

I'm still thinking this is a good idea.
A meta that folks could contribute to would help people I'm sure, with a subsection for different CAD software people use.

A few tutorials I watched all said the same thing: The best thing to do is to copy parts from other libraries to make your own. It saves time and helps one understand the part creation process.

I'll let go of this, but I don't think any of the arguments made against having one are stronger than the educational value that would be gleaned for those new to pcb design.  

Examples where it would have been beneficial for people:
http://www.groupdiy.com/index.php?topic=39722.0
http://www.groupdiy.com/index.php?topic=36090.msg446460#msg446460
This is just doing a search on "parts libraries".

I've already modified some of harpos contributions to fit my own; I used his as a baseline.

I'll start a thread if anyone shows any interest. Once I actually HAVE an Eagle library that uses parts not found in sparkfun, ect. 

Found this lib for eagle this morning...

It has basic parts that I needed. For example I need a standard 1 deck pot. that I could mount off board. it has it. As well as some other cool stuff like generic resistors  layouts and such.

http://gaussmarkov.net/eagle/lbr/gm-lbr.zip

and the website it came from incase the link doesn't work

http://gaussmarkov.net/wordpress/tools/software/eagle/eagle-2-libraries/

I'm designing on an older version of Eagle that doesn't accept the new eagle library formats...  I'm a little too cheap to buy a new license right now.

Perhaps a smaller PCB could be done on the trial software, but 4" x 3.2" doesn't cut it for my products.

Sounds like a personal problem (for me).

JR

I have the opposite problem... I have a more current version of eagle and some of the older libs on the cadsoft site no workie