You can follow the instruction given below for easily creating Gerber or Ecellon files in Eagle.
1. Select the CAM Processor and execute it.
2. Click the option “Option for Job” in the “File” menu.
3. In the User Interface that opens, you have to supply the right *.cam file. For example, choose “gerbXXX-4layer.cam” where XXX stand for the example that you want to open.
4. Now in the CAM Processor, this new project is launched and the required tools are configured in the right side window.
5. Dimension has to be activated in each layer by selecting it. Now you can see outer edges of the PCB. You have to uncheck the checkbox with the Mirror.
6. Now this is finalized and you can finish the project by selecting “Process Job” .
7. Gerber files are then generated in the project folder by CAM Processor. Number of files (6 for a 2-layer design) in the folder depends upon the layers of your Job.
8. To generate a file with information regarding holes of the design, you need to open excellon.cam in steps two and three while selecting the *.cam file. Press “Process Job” and you’ll get excellon file in the project folder.
9. Create a zip archive containing the above mentioned files and send it to sales88@greattong.com.