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Eagle Parts Library for QRP projects?


Curt
 

At age 71, decided to attempt learning how to design a PCB for fabrication by the numerous available shops.  Selected Eagle, using the free version at least for starting, managed to draw a schematic and produce a board design for a simple crystal transmitter using parts from the numerous available libraries.  Managed to build one "device" in a personal "library".  When the fabricated board arrived, unfortunately the parts pads weren't as large as I wanted, and the device I had built was larger than would have liked.  The board is likely usable, but nothing would care to share.

So, back to the drawing board.

I think the defaults in the program aren't what an amateur should use, but am not sure what the defaults should be.  For example, default design rules for pad around hole has a minimum of 10 mils and maximum of 20 mils.  What should they be?   

I think the parts vendor libraries are voluminous and targeted toward commercially designed PCBs.

With the many  PCBs designed and fabricated for QRP projects, there are libraries already populated with parts appropriately scaled for the parts that we use with QRP projects.   I have looked unsuccessfully for such a library.  I could build my own of course, but not sure of the value reinventing that wheel.

Is there a resource for QRP PCB design rules and library?  Or is every hobbyist rolling their own?

73, Curt KB5JO


Dave NZ1J
 

Hi Curt,
 
Like you, I prefer to have enough copper on the board to be able to work with it easily.
 
For something like a DIP package, the lead spacing is 0.100"  The drilled holes are about 0.040"  That leaves 0.060" of fiberglass between the holes.  If 0.020" annular rings are used around each hole, that leaves 0.020" of space between the rings.
 
As you say, modern manufacturing uses pretty tight tolerances.  To pass a trace between those DIP pads, things need to be squeezed a bit.  I think the standard libraries may allow room for that trace as the default.  Though it is some extra work for us, customizing the rings to be larger where possible makes for a board that is more tolerant of some rework.  We can also use oblong pads that leave room for the trace, but provide more copper where there isn't an issue.
 
I also choose wide traces wherever possible.  Sometimes the default is 0.012" or even narrower.
 
I'm sorry that I don't know of any libraries that will do what we want.  Please let us all know what you find.
 
73,
Dave NZ1J


---------- Original Message ----------
From: "Curt via Groups.Io" <rhulett1@...>
To: main@4SQRP.groups.io
Subject: [4SQRP] Eagle Parts Library for QRP projects?
Date: Tue, 16 Apr 2019 08:16:37 -0700

At age 71, decided to attempt learning how to design a PCB for fabrication by the numerous available shops.  Selected Eagle, using the free version at least for starting, managed to draw a schematic and produce a board design for a simple crystal transmitter using parts from the numerous available libraries.  Managed to build one "device" in a personal "library".  When the fabricated board arrived, unfortunately the parts pads weren't as large as I wanted, and the device I had built was larger than would have liked.  The board is likely usable, but nothing would care to share.

So, back to the drawing board.

I think the defaults in the program aren't what an amateur should use, but am not sure what the defaults should be.  For example, default design rules for pad around hole has a minimum of 10 mils and maximum of 20 mils.  What should they be?   

I think the parts vendor libraries are voluminous and targeted toward commercially designed PCBs.

With the many  PCBs designed and fabricated for QRP projects, there are libraries already populated with parts appropriately scaled for the parts that we use with QRP projects.   I have looked unsuccessfully for such a library.  I could build my own of course, but not sure of the value reinventing that wheel.

Is there a resource for QRP PCB design rules and library?  Or is every hobbyist rolling their own?

73, Curt KB5JO



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Curt
 

Well, as it happens, just now found the SparkFun libraries https://www.sparkfun.com/EAGLE , which look promising.  Not sure how missed these. I am going to wander through those parts to see what the footprints are like.  Also that site seems to have some tutorials that ought to be useful.

Curt KB5JO


Mike D
 

The Sparkfun libraries are a good resource for getting started. 

I use Eagle extensively, and generally Mouser has libraries available for most parts they stock.  I usually order most of my components from there anyways, so it's a good resource.

Mike kd5rjz

On Tue, Apr 16, 2019 at 11:28 AM Curt via Groups.Io <rhulett1=consolidated.net@groups.io> wrote:
Well, as it happens, just now found the SparkFun libraries https://www.sparkfun.com/EAGLE , which look promising.  Not sure how missed these. I am going to wander through those parts to see what the footprints are like.  Also that site seems to have some tutorials that ought to be useful.

Curt KB5JO


Nick Kennedy <kennnick@...>
 

I've found the same thing, Curt. Using ExpressPCB to make SMT toner transfer designs, the footprints that are standard are no-doubt fine for machine assembly or paste & heat, but if you are using a soldering iron you long for a bit more room to put down your soldering iron tip and solder without disturbing the part. 

Those little SOT23-3 transistors and regulators are especially difficult. But even big ole 1206 parts can benefit from a bit more foil. So I do make a lot of custom parts, sometimes starting with what came with the program and making the pads larger if there's room.


73-

Nick, WA5BDU