Old Gerber & Drill File Format

For general questions regarding the software and for all questions that do not fit in any of the threads above.
Post Reply
Message
Author
OldTechie
Posts: 11
Joined: 19 Sep 2015, 15:51

Old Gerber & Drill File Format

#1 Post by OldTechie » 14 Oct 2022, 09:31

I've found an old project (not Diptrace format) that has the Gerber files (but none of the original source CAD files) that I'd like to build. However the drill file is WAAAAY out of proportion to the rest of the Gerbers. Viewing the Gerbers in Gerbv shows the problem very plainly.
Does anyone know of a utility (hopefully free) that I could use to fix the scaling and coordinates of the old drill file?
I know that I could completely recreate the design in Diptrace, but it surely would be much easier if I could just fix the drill file. This is a one-off project for me, not show-stopping if I must recreate it in Diptrace, but looking for an easy way to fix the problem.

Thanks for any help,
DaveM

OldTechie
Posts: 11
Joined: 19 Sep 2015, 15:51

Re: Old Gerber & Drill File Format

#2 Post by OldTechie » 16 Oct 2022, 05:00

HA!!!
I figured out how to fix the problem, almost by accident!! I use Gerbv, a freeware Gerber viewer to confirm my PCB design is correct. I knew the problem was in the drill file, so I concentrated on that layer in Gerbv.
I tried changing the scale and translation numbers in the Layer/Edit Layer menu, but things only got worse.
Then, checking the format of the drill file in the Layer/Edit File_Format menu revealed that the number of digits was set to 5 digits. Since the scale of the drill file seemed to be enlarged by a factor of 10, I changed the Digits settng to 4 digits, and VOILA, everything was all in place! The drill holes matched the pads and mounting holes exactly.
I saved the drill layer with File/Save Active Layer, reloaded all the files into Gerbv, and everything was good.
So now, I can send all the Gerber files to the fab house; hopefully, they will be good enough to make the board.

Apparently, the person who originally designed the project didn't have the Gerber job parameters set correctly, causing the scaling and registration problems with the drill file. I don't know how the fab house handled the problem and was able to make a good board, but apparently they were aware of the problem, and handled it correctly. But now, the old file formats are rejected by the fab houses, and expect to see properly formatted and scaled files.
Maybe this will help someone else down the road from going crazy trying to build a project made with old software.

Cheers!
DaveM

Post Reply