Most of the plans downloaded from ThePlanCave will be compressed to a Zip format, here are steps to take to open them.
If the ZIP file is protected with a password you can enter a simple command to open it using Apple’s native terminal emulator.
Right-click the ZIP file on your Mac, click “Open With” from the pop-up menu and then click “Archive Utility” to decompress the file.
To unzip a single file or folder, open the zipped folder, then drag the file or folder from the zipped folder to a new location.
To unzip all the contents of the zipped folder, press and hold (or right-click) the folder, select Extract All, and then follow the instructions.
If you have the appropriate app on the iPad, the zipped file can be sent to that app to be unzipped. For example,
someone emails you five photos that are zipped. You tap on the zipped file in the email, a popup window will ask you
if you want to open the file in an app, for example, Zip Browser
Google Play to access unzip apps