Tried install OpenSCAD.

doc/erko_howto_tools.txt

@@ -801,3 +801,43 @@ https://lwn.net/SubscriberLink/847039/3016fa7278000b77/
 - upload the zip file and publish the DOI.
 
 
+
+*******************************************************************************
+* Install OpenSCAD
+*******************************************************************************
+
+https://ubuntuhandbook.org/index.php/2019/01/install-openscad-ubuntu-18-10-18-04/
+
+> sudo apt-get install openscad  # werkt niet voor Unbuntu 18.04 = Mint 19.03
+
+> sudo add-apt-repository ppa:openscad/releases  # use Personal Package Archive = PPA instead
+You are about to add the following PPA:
+ Backports of OpenSCAD stable releases
+ More info: https://launchpad.net/~openscad/+archive/ubuntu/releases
+Press Enter to continue or Ctrl+C to cancel
+
+Executing: /tmp/apt-key-gpghome.2EIWTkQ4Yk/gpg.1.sh --keyserver hkps://keyserver.ubuntu.com:443 --recv-keys CB86A1742C718B1EEA0440B3176F9F68AD382CA4
+gpg: key 176F9F68AD382CA4: public key "Launchpad PPA for OpenSCAD packagers" imported
+gpg: Total number processed: 1
+gpg:               imported: 1
+
+> sudo apt-get update
+Hit:1 http://dl.google.com/linux/chrome/deb stable InRelease
+Hit:2 http://archive.ubuntu.com/ubuntu bionic InRelease
+Get:3 http://ppa.launchpad.net/openscad/releases/ubuntu bionic InRelease [15,9 kB]
+Get:4 http://archive.ubuntu.com/ubuntu bionic-updates InRelease [88,7 kB]
+Hit:5 http://ppa.launchpad.net/remmina-ppa-team/remmina-next/ubuntu bionic InRelease
+Get:6 http://archive.ubuntu.com/ubuntu bionic-backports InRelease [74,6 kB]
+Hit:7 http://security.ubuntu.com/ubuntu xenial-security InRelease
+Hit:8 http://archive.canonical.com/ubuntu bionic InRelease
+Ign:9 http://packages.linuxmint.com tricia InRelease
+Get:10 http://ppa.launchpad.net/openscad/releases/ubuntu bionic/main i386 Packages [2296 B]
+Hit:11 http://security.ubuntu.com/ubuntu bionic-security InRelease
+Get:12 http://ppa.launchpad.net/openscad/releases/ubuntu bionic/main amd64 Packages [2296 B]
+Get:13 http://ppa.launchpad.net/openscad/releases/ubuntu bionic/main Translation-en [1020 B]
+Hit:14 http://packages.linuxmint.com tricia Release
+Fetched 185 kB in 1s (191 kB/s)
+Reading package lists... Done
+
+> sudo apt-get install openscad
+Gelukt !