Latching, FRESH/DEAD Cards - Backstage cart lip (one piece, strongest)
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What it holds: Two 18 V packs, even the big 12 Ah and Forge packs, slide in toward the cart and lock with their own latch. Flip cards show FRESH or DEAD at a glance. Fits a 256 mm bed; add docks side by side for more bays.

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_RA2_m18_pair_lip.stl  (supports: no (unless your slicer warns))
  - RA_flip_card.stl  (supports: no (unless your slicer warns))
  - RA_rail_slice_M18_p04.stl  (supports: no (unless your slicer warns))
  - RA_rail_slice_M18_m04.stl  (supports: no (unless your slicer warns))

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: One piece with the Magliner/cart lip block (strongest). Holder top level with the block top; the kick pads bear on the cart side below the deck. Fit both M5 heat-set insert + thumbscrew lip clamps (up to 3.35 kg with 2 x 12 Ah). Prints upside down (top face and block top on the bed), no supports. ~326 g. Plus 2 x RA_flip_card and 2 x 45 mm of 1.75 mm filament (card pins). Also included: fit slices (RA_rail_slice_M18_p04.stl, RA_rail_slice_M18_m04.stl).

HOW IT WORKS
  Spare packs on a film cart live in a box, a bag, or on the deck where they slide around. This dock gives two 18 V packs (fits Milwaukee M18 CP2.0, XC5.0, HIGH OUTPUT 6/8/12 Ah and Forge 8/12 Ah) a fixed home on the cart side, and you can see from across the stage which one is charged. Max 2 x 12 Ah packs per dock. Need more? Put two docks side by side, or add RA1 / RB2 next to it.
  How it works: each bay is a dummy tool foot. Hold a pack upright, push it in toward the cart under the foot, and it clicks: the pack's own spring latch pops up into the window in the foot roof. You can see it from above, so you know it's locked. The pack hangs on the rail lips the way it hangs under a drill, so a bump pushes it onto the rails, not off them, and two small crush ribs in each bay stop it rattling. To take one, press the pack's release buttons and pull it toward you, one-handed. The bays are 110 mm apart, which leaves a 24 mm gap between two 86 mm-wide HIGH OUTPUT or Forge packs: room for gloved fingers on the side release buttons.
  FRESH / DEAD flip cards: each bay has a flush pocket on top with a hinged card on a 1.75 mm filament pin. Lay the card toward you and it shows green FRESH. Flip it over toward the cart and it shows red DEAD. You can read it from above when you walk up to the cart, and it travels with the bay, not the pack. To assemble, drop the card in its pocket, push a length of 1.75 mm filament through the small hole in the side of the bay, through the card, out the far side, and snip it flush. The card is about 2 g: print it red for the first 1.8 mm and green above that (AMS filament change on the layer slider).
  Cart facts (on the lip adapter)

  - The part sticks out 98 mm from the cart side. With packs: 136 mm with XC5.0, 174 mm with HD12.0. Packs hang to 58 mm (XC5.0) / 86 mm (HD12.0) below the deck. Use a cart end or a side that does not brush doorways.
  - Hangs 66 mm below the deck (the part). Its top is 34 mm above the deck, level with the adapter.
  - Kick pads on the back bear on the cart side near the bottom edge, 66 mm below the deck. The cart needs that much flat side under the lip.
  - Size 220 x 97 x 100 mm (along x out x tall)
  - Rated 4.5 kg on 3 tongues, rolling cart, lock screws fitted. 2 x HD12 = 3.1 kg + holder 0.25 kg = 3.35 kg (max 2 x 12 Ah per module); 2 x XC5.0 = 1.4 kg.
  Lock screws are required, and this is rated for a rolling cart. These parts carry their weight 100-115 mm out from the cart side, so a hard jolt pries on the DOCK tongues much harder than a holder that sits close in. Fit the M5 lock thumbscrew in every adapter, every time. The rating is for pushing the cart around a stage, a lot or a ramp. It is not yet rated for lift gates or riding in a truck: take the packs off for those, or run the moment bench test in the build notes first.
  Mount (DOCK): every holder in this collection has DOCK tongues on its back: 38 mm wide 45 degree dovetails that drop into a DOCK adapter and click. The lip adapter (A_MLN_lip, in the DOCK system collection) grips the 3.4 mm upright shelf lip of Backstage Equipment and Magliner-style carts. The same holder also fits the ToughBuilt bar, round tube, square tube and T-slot adapters. Parts with three tongues use three adapters set 60 mm apart with the DOCK spacing gauge. To lift a holder off: undo the lock screws, press each adapter's thumb tab, then lift.
  Safety: no metal, no contacts and no terminals anywhere in these parts. At the contact end of every bay there is a 3 mm air gap (18 V) or 6 mm (12 V), so nothing touches the pack contacts. Never put loose metal (bits, screws, coins) in a bay.

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/#ra2-m18-pair

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.
