title_body: why do drone frames have spaces and holes This may sound like a very dumb question, but I am building my first quadcopter and I just realized that some frames have these perfectly symmetrical holes/spaces.
  I used up all the screws on mine, so I don't think I have to actually use those spaces, but why are they there?
  Is it to allow the user to make more modifications? Are some of the spaces/holes deliberately made to fit certain screws for modifications?
  This is the drone frame that I am specifically referring to, but this applies to a lot of other frames (and even electronics in general) as well.
upvoted_answer: A major consideration is weight reduction; if material can be removed without significantly reducing the strength of the item, this will result in an increased payload or flight duration. This is particularly evident in the motor arms of the product you linked, as the triangular shapes are renowned for their relative strength.
  Another advantage of this is that it allows additional equipment to be attached easily, with cable ties or similar; in some cases I expect the cut-outs will be designed with this in mind - for example; a selection of parallel cut-outs can allow for a wider range of battery sizes to be securely attached to a frame.