A Stupid Eagle Question: Non-Circular Holes

[jaybird3rd]

I'm hoping this will be a simple question to those who have more experience with circuit board layout than I do.

 

I'm working on the final revisions to my Mattel Aquarius multi-cart circuit board, using Eagle 5.10.0. It needs to include elongated oval holes in the top corners for the screw posts, like this:

 

 

I currently have these holes specified as filled polygons in the Dimension, Holes, and Drill layers. They're showing up in the top copper layer when I export the design to Gerber files, but my manufacturer is asking me to move them into the drill file instead. I've selected the correct layers in the Eagle CAM processor, but I can't get these holes to show up in the drill file. I've Googled every permutation of "eagle polygon hole drill file" that I can think of, and I can't find anything relevant.

 

So, my question is: has anyone here used holes similar to these in other projects, and if so, how did you get them into the drill file? Should they be polygons, or should I specify them some other way?

 

Thanks in advance!

[+batari]

AFAIK, the drill file can only specify circular holes and not ovals. Do you really need an oval, or will two overlapping holes do? If you need an oval, I'd try a couple of holes for the ends over a rectangular cutout on the dimension layer and see what the board house says.

 

Making holes is easy - In the draw menu, select hole. Manually enter the correct diameter, and place the hole.

[jaybird3rd]

AFAIK, the drill file can only specify circular holes and not ovals. Do you really need an oval, or will two overlapping holes do? If you need an oval, I'd try a couple of holes for the ends over a rectangular cutout on the dimension layer and see what the board house says.

 

Making holes is easy - In the draw menu, select hole. Manually enter the correct diameter, and place the hole.

If the drill file can only specify circular holes, that's probably the reason. I already have several circular holes on this board, but when I tried to overlap them, the board failed Eagle's DRC checks. The holes need to be ovals because the posts are in slightly different positions depending on which variety of cartridge shell the board is used in: some have screws, while others have plastic pins.

 

Another option that occurs to me is to specify these holes in the Mill layer instead (a Gerber .GML file). I'll bring these alternatives to the board house to see what they say.

 

Thanks!

[+batari]

AFAIK, the drill file can only specify circular holes and not ovals. Do you really need an oval, or will two overlapping holes do? If you need an oval, I'd try a couple of holes for the ends over a rectangular cutout on the dimension layer and see what the board house says.

 

Making holes is easy - In the draw menu, select hole. Manually enter the correct diameter, and place the hole.

If the drill file can only specify circular holes, that's probably the reason. I already have several circular holes on this board, but when I tried to overlap them, the board failed Eagle's DRC checks. The holes need to be ovals because the posts are in slightly different positions depending on which variety of cartridge shell the board is used in: some used screws, while others used plastic pins.

 

Another option that occurs to me is to specify these holes in the Mill layer instead (a Gerber .GML file). I'll bring these alternatives to the board house to see what they say.

 

Thanks!

Don't worry about the DRC. Just about every one of my boards had a DRC "failure" of some kind. Many DRC errors are meaningless as far as manufacturability is concerned. It's really up to the board house if they will allow overlapping drills - some allow it, some don't, and some allow it for production boards but not prototype boards, etc.

[+Stephen Moss]

If the drill file can only specify circular holes, that's probably the reason. I already have several circular holes on this board, but when I tried to overlap them, the board failed Eagle's DRC checks.

I have not used Eagle but in a lot of PCB software you can select what is and is not checked in the DRC, provided the rest of the design passes the DRC either ignor the flagged error or if that is preventing Eagle from producing the Gerber file have you tried disabling relevent DRC rule prior to greating the Gerber?

 

Another option that occurs to me is to specify these holes in the Mill layer instead (a Gerber .GML file). I'll bring these alternatives to the board house to see what they say.

 

Thanks!

That is probably the better method as it will produce a neater result. Using holes usually requires you to finish it off with a needle file to smooth the side of the oval off due to the curvature of the drill bit.

[+batari]

Another option that occurs to me is to specify these holes in the Mill layer instead (a Gerber .GML file). I'll bring these alternatives to the board house to see what they say.

 

Thanks!

That is probably the better method as it will produce a neater result. Using holes usually requires you to finish it off with a needle file to smooth the side of the oval off due to the curvature of the drill bit.

I don't know about that - milling and drilling are different things. They both make rounded shapes but milling bits generally can't drill holes. You would need to drill a hole first at least to get started. Perhaps you could drill one hole then mill out the rest of the oval. Edited October 28, 2010 by batari

[jaybird3rd]

Okay, I talked to the board house, and adding those holes to the Mill layer was the easiest option. I did so and sent it back to them, and they just said that it's now okay to process. Thanks again for all your help!

[candle]

in the industry, we call these ovals ports

if software can't use port holes, then you need to draw them manually as set of overlaping holes - some pcb houses may object to this as they

a) can do the ports already - best to discuss how to obtain them

b) will break dills if holes are placed too close to each other

 

if you have relativly large diameter of port to cut out, and don't have any other means to do it but to make overlapping holes - go for it

[Game-Tech.US]

Okay, I talked to the board house, and adding those holes to the Mill layer was the easiest option. I did so and sent it back to them, and they just said that it's now okay to process. Thanks again for all your help!

Who do you use for manufacture?

[Video]

It seems to me you could tell it to do two circle holes, and one square one in between to smooth the holes out, that would give you a elongated hole with smooth sides, or you could try for overlapping circles, though you'd get sawtooth patterns along the edge of the hole.