All pins off grid, pads move when viewing gerbers

Eric Griswold wrote:

Hi, I'm new to eagle. Designing a small two-layer relay board.

 

When I place the relays from the library, the outer packages "snap"

to the grid, which I have set at .025. However, apparently all the

pins are off grid and the DRC gives me about 20 errors. Is this

anything to worry about? Can I/should I make the PINS snap to the

grid instead of the package outline, and if so, how do I do this?

Your pads don't need to be on-grid.  For tidy looking routing, start your

traces at these off-grid pads and route them to an on-grid point.

More troubling, when I view the Gerbers with a free viewer (Viewmate

10) some of the pads are displaced between the two layers... in one

case, they are "next to" each other instead of being "on top of" each

other as they should be.  Is this related to all the pins being off

grid?

I don't know what is wrong there.  Sometimes Gerber formats get confused.

It's best to use the RS274X format, as produced by the ger274x.cam CAM file.

I use GC-Prevue to peruse the Gerbers produced by Eagle.

--

Bert Menkveld

Eric Griswold schrieb:

When I place the relays from the library, the outer packages "snap" to the

grid, which I have set at .025. However, apparently all the pins are off

grid and the DRC gives me about 20 errors. Is this anything to worry about?

Can I/should I make the PINS snap to the grid instead of the package

outline, and if so, how do I do this?

As Bert already mentioned, the pads don't need to be on-grid. Many parts

(especially those with "metric" packages) have off-grid pads, regardless

of the grid you use for routing.

Just take care to always start routing at the off-grid pad and end

somewhere on grid.

More troubling, when I view the Gerbers with a free viewer (Viewmate 10)

some of the pads are displaced between the two layers... in one case, they

are "next to" each other instead of being "on top of" each other as they

should be.  Is this related to all the pins being off grid?

Simply take a /working/ gerber viewer. I have heard of many (more or

less serious) problems with Viewmate. Personally, I prefer GCprevue (in

fact an older version...).

Tilmann

Eric Griswold wrote:

Hi, I'm new to eagle. Designing a small two-layer relay board.

 

When I place the relays from the library, the outer packages "snap" to the

grid, which I have set at .025. However, apparently all the pins are off

grid and the DRC gives me about 20 errors. Is this anything to worry about?

Can I/should I make the PINS snap to the grid instead of the package

outline, and if so, how do I do this?

 

If the pins would lie on the grid then it is better practice to line them up

that way when you make the package rather than the package outline on grid.

However off grid DRC errors are not something to worry about unless you have

some special conditions. I never have that option checked in the DRC (or angle)

cheers

David