Slide-on wall mount for Samsung Galaxy Tab S6 (SM-T860 / T865 / T867), landscape
Parts to print. Units are millimetres. All files are watertight solids.

  plate.stl        wall plate with tongue, 120 x 135 x 6      print as-is, flat side down, no supports
  frame.stl        U-frame glued to the tablet's back, 110 x 100 x 3    print as-is, no supports
  block_p30.stl    pin block, pin pitch 3.0 mm  \
  block_p33.stl    pin block, pin pitch 3.3 mm   > 20 x 11.5 x 25, already stood on its base; print all three
  block_p35.stl    pin block, pin pitch 3.5 mm  /   (two grams each), the one matching the tablet's pads is used

Print settings
  Material: PLA, black.  Layer height 0.2 mm.  Infill 40 %.  Walls: 3 perimeters.  Top/bottom: 4 layers.
  Scale 100 %, no fit compensation or hole scaling.  No supports; all overhangs are 45 degrees.
  The tongue on the plate and the opening in the frame are a sliding dovetail with 0.3 mm clearance per
  side; dimensional accuracy there matters more than anywhere else.  The four small holes in each block
  are 2.4 mm on purpose and get drilled to 2.5 mm after printing.

What is what
  plate.stl : screws to the wall (4 countersunk #8 holes, 8 mm in from its top and bottom edges). The raised
              tongue is what the frame hangs on. 16 mm hole for the cable and the 12-to-5 V converter. A
              dovetail slot across the stem takes the pin block; the block slides to line up with the tablet's
              pads, then is glued. A 4 mm groove on the wall side carries the wires to the hole.
  frame.stl : glued to the tablet's back, centred, top edge about 29 mm below the tablet's top edge (the
              glue-up procedure sets this). Its dovetail opening hooks under the tongue; lift 70 mm to remove.
  block.stl : holds four 2.5 x 9 mm spring pogo pins seated in a 1 mm pocket so the tips stand 2 mm above
              the block's shoulder; the shoulder sits 1 mm below the tablet's edge, so the pins compress 1 mm.
              The body reaches back to the wall; a 3.5 mm channel on its bottom and back faces carries the wires.

mount.scad is the OpenSCAD source; every dimension is a named variable at the top.
Render a part:  openscad -D 'part="plate"' -o plate.stl mount.scad     (block: add -D pin_pitch=3.3)