Gerber files - mirror option

"Markus Baertschi" <markus@markus.org> schrieb im Newsbeitrag

news:fuf9t9$jci$1@cheetah.cadsoft.de...

 

When I use the default gerb274x cam processor for the solder side

layers the 'Mirror' option is set. This makes verifying the produced

gerbers difficult as the layers don't sit correctly on each other.

 

Is this required by board-houses ?

If I switch Mirror off for verification and forget to re-run the

cam processor with Mirroring on will I get a non-functional board ?

 

Markus

Never had any problems with unmodified (non-mirrored) data. Many years ago I

used to mirror the bottom layer, no problems either. In theory you should be

able to send out anything you want as long as you describe all details of

the chosen format to the boardhouse, and as long as they accept it. But

maybe it reduces the likelihood of mistakes somewhat, if you stick to an

"all layers in the same format" scheme.

T.

T.Strothmann wrote:

Never had any problems with unmodified (non-mirrored) data. Many years ago I

used to mirror the bottom layer, no problems either. In theory you should be

able to send out anything you want as long as you describe all details of

the chosen format to the boardhouse, and as long as they accept it. But

maybe it reduces the likelihood of mistakes somewhat, if you stick to an

"all layers in the same format" scheme.

 

T.

 

I can see your point. But the gerb274x.cam file by default does mirror

the bottom layers. At the same time board houses say you should

carefully examine the gerbers, which seems somewhat contradictory as you

can not verify your gerbers if half of them are the wrong way round.

I did not see any remarks about this in any of the tutorials and am just

wondering if there is a consensus about thet.

Markus

Markus Baertschi wrote:

T.Strothmann wrote:

Never had any problems with unmodified (non-mirrored) data. Many years

ago I used to mirror the bottom layer, no problems either. In theory

you should be able to send out anything you want as long as you

describe all details of the chosen format to the boardhouse, and as

long as they accept it. But maybe it reduces the likelihood of

mistakes somewhat, if you stick to an "all layers in the same format"

scheme.

 

T.

 

I can see your point. But the gerb274x.cam file by default does mirror

the bottom layers. At the same time board houses say you should

carefully examine the gerbers, which seems somewhat contradictory as you

can not verify your gerbers if half of them are the wrong way round.

 

Way back when eagle was started you would be using film and need the

emulsion next to the PCB photo resist layer. So it needed to be printed

mirrored. Most of the time the Gerbers (HPGL possibly) went from the

disk to the photo/pen plotter without having (much of) a computer

available to mirror the layer.

I did not see any remarks about this in any of the tutorials and am just

wondering if there is a consensus about thet.

 

Markus

This is more of a legacy default and I have unchecked the mirror on my

cam files I use.

Paul R.

"Paul Romanyszyn" <pgr@arcelectronicsinc.com> schrieb im Newsbeitrag

news:fuitr2$kiu$1@cheetah.cadsoft.de...

Markus Baertschi wrote:

T.Strothmann wrote:

Never had any problems with unmodified (non-mirrored) data. Many years

ago I used to mirror the bottom layer, no problems either. In theory you

should be able to send out anything you want as long as you describe all

details of the chosen format to the boardhouse, and as long as they

accept it. But maybe it reduces the likelihood of mistakes somewhat, if

you stick to an "all layers in the same format" scheme.

 

T.

 

I can see your point. But the gerb274x.cam file by default does mirror

the bottom layers. At the same time board houses say you should carefully

examine the gerbers, which seems somewhat contradictory as you can not

verify your gerbers if half of them are the wrong way round.

 

Way back when eagle was started you would be using film and need the

emulsion next to the PCB photo resist layer. So it needed to be printed

mirrored. Most of the time the Gerbers (HPGL possibly) went from the disk

to the photo/pen plotter without having (much of) a computer available to

mirror the layer.

I did not see any remarks about this in any of the tutorials and am just

wondering if there is a consensus about thet.

 

Markus

This is more of a legacy default and I have unchecked the mirror on my cam

files I use.

 

Paul R.

Yes. Did the same. No problems checking the gerber plots using "GCPREVUE",

no problems no matter the board house I dealt with.

T.

T.Strothmann wrote:

"Paul Romanyszyn" <pgr@arcelectronicsinc.com> schrieb im Newsbeitrag

This is more of a legacy default and I have unchecked the mirror on my cam

files I use.

Paul R.

Yes. Did the same. No problems checking the gerber plots using "GCPREVUE",

no problems no matter the board house I dealt with.

T.

Thanks Gentlemen,

that's the info I was looking for. I'll happily uncheck the mirror

option and save is as default.

I was following the instructions given by Olimex. They are quite

specific for many things, but this was not mentioned at all.

Regards   Markus

Markus Baertschi wrote:

T.Strothmann wrote:

"Paul Romanyszyn" <pgr@arcelectronicsinc.com> schrieb im Newsbeitrag

This is more of a legacy default and I have unchecked the mirror on

my cam files I use.

Paul R.

Yes. Did the same. No problems checking the gerber plots using

"GCPREVUE", no problems no matter the board house I dealt with.

T.

 

Thanks Gentlemen,

 

that's the info I was looking for. I'll happily uncheck the mirror

option and save is as default.

I was following the instructions given by Olimex. They are quite

specific for many things, but this was not mentioned at all.

 

Regards   Markus

With Olimex you can just send the *.brd file and they do the

post-processing.

Has worked well for me over several different two-layer boards.

John G.

John Giddy wrote:

With Olimex you can just send the *.brd file and they do the

post-processing.

Has worked well for me over several different two-layer boards.

John G.

I know, but Olimex has a quite hing limit on drill and copper size. I'm

looking into one board where I'd need smaller features and Olimex would

not work out. If I'm at it, lets learn !

Markus