iPad friendly arms for tablet mount

Remade the arms from the ground up, removing a lot of the previously needed hardware. 

Removed: 

• The toothed plates and mating surfaces for retaining the cut elastic cords
• All of the 4-40 hardware. 
  • (I literally could not source the bolts locally, none of the major box-stores within 50 miles carry hardware that small)

Changed:

• Raised the corner walls to accommodate my folio case.
• Shortened the arm itself to better fit my iPad.
• Opted to use off-the-shelf hair elastics. one for retracting each of the arms, and one for each corner (Double wrapped to use up excess length.
• Added a single M3 hole to anchor the two bands.
• Moved one of the two hooks retaining the elastics on the corners, so that they could better hold my iPad.
   
• NOT SHOWN IN MODEL I drilled out the holes on the arm retaining plates to accept m3 screws as well, but I didn't remake the other models to reflect that. 
  
  NOTE: I am using this adapter plate so I may use mount it on this articulating arm. (Not directly related to my remixed part, but relevant to my specific build.)

Remade the arms from the ground up, removing a lot of the previously needed hardware. Generally made more accessible and easier to print.