[sdiy] Building parts in Eagle - continued

[Ingo Debus]

Am 12.12.2009 um 02:39 schrieb Julian:

> However, now i want to go and alter some things in the package.   
> Notably, i want to increase the pad sizes.

Uh, careful. There's an ugly pitfall concerning pad sizes. See below.


> If i try and edit the package, i get the "package is in use"  
> error.  I assumed this ment it was in the scematic and board file,  
> so i coppied and renamed the whole lib. file, and im still getting  
> the error.

No, that's not because the package is in use in a board or schematic.  
That's most probably because the package is in use in a device (in  
the same library) and you're trying to change something that woudn't  
fit with how the package is used in the device (for instance,  
deleting pads that are used).

There seems to be no other way around this than deleting the whole  
device - that's pretty unelegant. Isn't there any way to remove a  
package from a device? Does anybody know?

BTW, my eagle version (5.6.0 for Mac OS) shows a much more elaborate  
error message than "package is in use" in this case. It's something  
like "cannot delete a Pad/Smd that's used in a device". Are you using  
an older version?


> So, what im wondering is -
>
> How do i get to edit this package now?
> And, when i can, i didnt initially see any way to increase the pad  
> size.

There are two ways to change pad sizes in libraries:
1. the traditional one (also possible in eagle 4): use change (the  
wrench tool), a popup will come up, select Diameter, then select the  
new diameter from the next popup, or if the diamater you want is not  
in the list, select "..." and enter a new diameter. Then click on all  
the pads you want the diameter to change.
2. the modern way (new since version 5): use info (the i icon) and  
click on the pad or just right-click on the pad with any tool  
selected and change the diameter in the box that comes up then.

And now for the pitfall mentioned above:
you probably already noticed the the diameter of a pad can be set to  
"auto". This means the diameter of the pad will depend on the  
diameter of the hole. But where this dependency is set, is very well  
hidden: it's in the design rule check. So if you change design rule  
parameters you not only change the rules the board is checked  
against, you probably change the board itself! That's one of the most  
cranky things in Eagle IMHO. Not sure, but I think this even happens  
if the pad diameter in the library is set to a fixed diameter rather  
than to auto. I once investigated this, but I haven't my notes at  
hand. If anyone's interested, I can look this up.

> And... how do i copy 'devices' between libaries?

Both ways descibed by Tom Bugs work.You can do that from the control  
panel or use cut/paste (what everyone else but Cadsoft calls copy/ 
paste). Just create a new package or symbol and paste to it whatever  
you have "cut" earlier. The "clipboard" is not deleted when you close  
a library file and open another one.

Ingo