How do I create/enter/mod an empty map (unlimited resources) just for building schematics?

[Silanre]

I am probably overlooking something simple but as I have hit eradication maps I want to build some custom base designs. I have seen this videos where unloaders work without being connected to a base or container. Also would be fun to toy around with.
Thanks in advance...

[TheNightglow]

In Sandox you can build item sources (which just spawn items out of nowhere)
those are these "unloaders" you are talking about

When starting a custom game a menu opens where you can select which game mode you want to play (survival, sandbox, attack etc)

just pick sandbox and you ll have infinite resources and acces to sandbox structures like item spawners

[killall -q]

1. Create a new map in the editor
   
2. Menu -> Map Info -> Generation -> remove all the random terrains and ores
   
3. Menu -> Resize, make it big
   
4. Manually paint some special terrain tiles and ore patches for testing on
   
5. Place at least 1 core
   
6. Paint a single Enemy Spawn tile in a corner so it will be a valid survival map
   
7. Save
   
8. Play -> Custom Game -> select your test map -> Sandbox

[Silanre]

Thanks so much!