Found this bash script online that has quality documentation:
HOST=ftp.server.com #This is the FTP servers host or IP address.
USER=ftpuser #This is the FTP user that has access to the server.
PASS=password #This is the password for the FTP user.
# Call 1. Uses the ftp command with the -inv switches.
#-i turns off interactive prompting.
#-n Restrains FTP from attempting the auto-login feature.
#-v enables verbose and progress.
ftp -inv $HOST << EOF
# Call 2. Here the login credentials are supplied by calling the variables.
user $USER $PASS
# Call 3. Here you will change to the directory where you want to put or get
# Call4. Here you will tell FTP to put or get the file.
# End FTP Connection
After configuring and saving the .sh script, make it executable:
chmod +x ftpscript.sh
Lastly, configure your cronjob