Click-Lock Tilt Knuckle (1/4-20, Clamp Fan or Handheld Fan) - Backstage cart lip (one piece, strongest)
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What it holds: A tilt knuckle that hangs a fan from the cart and locks in 15 degree clicks. A floating lock washer lets it re-aim properly. Two heads: a 1/4-20 stud with a clamp-fan tab, or a handheld-fan cradle with a snap lip.

PRINT SETTINGS
  Filament:  PETG
  Walls:     5
  Infill:    35% gyroid
  Orientation: the files are already oriented for printing. Put them on the plate as they load;
               don't rotate them.

FILES AND SUPPORTS
  - H_QE_fan_knuckle_lip.stl  (supports: no (unless your slicer warns))
  - QE_lock_washer.stl  (supports: no (unless your slicer warns))
      how it lies on the plate: back face down, teeth up
  - QE_head_stud_clamp.stl  (supports: no)
      how it lies on the plate: flat bottom on the bed (hub axis horizontal), no supports
  - QE_head_handheld.stl  (supports: no)
      how it lies on the plate: tube bottom on the bed, no supports
  - QE_knob_M5.stl  (supports: no (unless your slicer warns))
      how it lies on the plate: top face down (hex pocket on the bed), stem up
  - QE_jam_wheel_quarter20.stl  (supports: no (unless your slicer warns))
      how it lies on the plate: flat, nut pocket up
  - QE_sleeve_32.stl  (supports: no (unless your slicer warns))
      how it lies on the plate: upright, TPU 95A or PETG
  - QE_sleeve_36.stl  (supports: no (unless your slicer warns))
      how it lies on the plate: upright, TPU 95A or PETG
  - QE_sleeve_40.stl  (supports: no (unless your slicer warns))
      how it lies on the plate: upright, TPU 95A or PETG

HOW IT MOUNTS
  BACKSTAGE CART LIP (ONE PIECE, STRONGEST)
    The cart-lip slot is printed into the holder, so it is one piece and as strong as it gets.
    Hold it tilted, hook the slot over the upright lip on the edge of a Magliner / Backstage-style cart
    shelf, and rock it down until it sits flat against the side.

    Notes for this holder: Strongest: one piece with the Magliner / cart-lip block, the holder fused to an 8 mm back plate that bears on the cart side down to the holder bottom. Sits at the same height as the swappable version on the Magliner adapter, 7 mm closer to the cart. Fit an M5 heat-set insert + M5 thumbscrew. Prints upright, floor down like the swappable version; use build-plate-only supports under the 14 mm deck-side flange of the lip block only. The heads, knob, lock washer, jam wheel and sleeves are the same for every version.

HOW IT WORKS
  Moving air is the cheapest heat relief on a long outdoor day. This knuckle hangs a fan on the cart, aimed where you stand.
  The lock: the head's hub has 24-tooth face gears on both sides. One side meshes with fixed teeth in the cheek. The other meshes with a floating lock washer, which is keyed so it can't turn but slides freely along the bolt. The star knob's stem presses the washer, and the washer presses the hub into the fixed teeth. Nothing can slip, so a bump can't swing the fan into anyone's face. To re-aim: loosen the knob 3-4 turns, tilt until it clicks (15 degrees a step), and tighten. An optional M10 wave washer turns the loose knuckle into a ratchet, so light fans hold each click while you turn the knob. Ticks on the cheek show each step.
  Head A (stud + clamp tab): a captured 1/4-20 stud takes any fan with a tripod thread, and the knurled jam wheel keeps it facing forward. The 44 x 40 x 22 mm ribbed tab gives a clamp fan something to bite.
  Head B (handheld fan cradle): a 44 mm bore with spring petals, slit sleeves for 32, 36 and 40 mm handles, and a front slot for the USB-C cable. The sleeve's top edge snaps in under a lip on the petal tips, so a bump can't lift the fan out. A firm pull takes it out.
  Real size with a fan fitted (measured on proxy fans, so check your own):

  - 4 in caged fan on the stud: reaches 113-137 mm out from the cart side and 128-153 mm above the deck. It clears the cart from 45 degrees down to 45 degrees up. Roll with it at +45.
  - 6.5 in clamp fan: stands about 210 mm above the deck and clears the cart from -45 to +15. Roll at 0.
  - Handheld fan: clears the cart from -45 to +45.
  - Folding the head flat to +90 (41 mm stick-out) is for the head with no fan on it.
  Safety: caged fans only. Keep the knob tight while rolling, and fit the dock lock screw for fans over 0.5 kg. A battery clamp fan (about 1.2 kg) is at the top of the rating, so keep it off lift gates.
  Mount: a DOCK tongue on the back (a 38 mm, 45 degree dovetail with a click latch). It fits every DOCK carrier adapter in this collection: the Magliner/Backstage 3.4 mm lip adapter, the ToughBuilt bar adapter and the 19-32 mm tube adapter. Drop it into the receiver from above until it clicks. To swap it, push the release tab and lift it out. For anything heavier than 1 kg, or on a lift gate, fit the M5 lock screw on the receiver.
  Hardware

  - Knuckle: 1 x M5 short heat-set insert, plus 1 x M5 x 50 hex bolt pressed into the knob top
  - Optional: 1 x M10 wave washer (DIN 137 B, about 10.5 x 21 mm)
  - Head A: 1/4-20 x 1-1/2 in hex bolt, plus a 1/4-20 hex nut in the jam wheel
  Original design. It is not the patented golf-cart fan clip.

OTHER MOUNTS
  The same holder also comes ToughBuilt bar (one piece), Dock (swap between mounts), Mountless (desk, shelf, case or screw to a panel). Pick the mount on the site: https://cart-tools.sdos-placeholder.workers.dev/#qe-fan-knuckle

TEST THE FIT FIRST
  Carts, bars and tape rolls vary a little. Before a long print, print the small fit test from the
  Test pieces section of the site (or this part at low infill) and check it on your own gear.

Not affiliated with or endorsed by Magliner, Backstage Equipment, ToughBuilt, Milwaukee, Hollyland, Eartec, Sekonic, Inovativ, Matthews or Manfrotto. Brand names only say what a holder fits.
