Can the 3.1 N·m hold-open torque be raised?

Answer: No. At 3.5 N·m one-hand opening turns stiff and bushing wear after 4400 cycles pushes decay past ≤10%; 3.1 N·m follows from a 4.2 mm wall and 360 N catches.

Why is slot-width tolerance set to ±0.34 mm?

Answer: Six slots share one mould, and ±0.34 mm keeps each cell of a Film V-mount battery & charger protective case from shifting sideways at 3.5 kg without crushing the foam; above upper tolerance that cell gains room to move.

How is the ≤0.58 mm drop shift measured?

Answer: Datum marks go on all six slots before release; their coordinates are stored, then re-read after the 1.0 m drop, and the largest offset decides. Six cells drifting together means base flex.

How is ≤10% torque decay over 4400 cycles judged?

Answer: Re-read the 3.1 N·m datum every 1100 cycles and join the four readings; flat-then-late-lift is bushing clearance, near-linear drops point to loose hinge preload.

Why is ≤3.5 kg judged cell by cell?

Answer: Each of the six cells loads on its own, so a neighbour's spare cannot offset an over-limit cell; per-cell rejection keeps the drop shift of a Film V-mount battery & charger protective case traceable by slot.

Film V-mount battery & charger protective case

Quick answer: A Film V-mount battery & charger protective case fixes hinge torque at 3.1 N·m and caps slot shift at 0.58 mm after a 1.0 m drop.

Hold-open hinge torque of the Film V-mount battery & charger protective case
Base locating-slot width tolerance
Slot shift on drop retest
Torque decay on the cycle rig
Per-cell load rejection line for film lots
FAQ

1. Hold-open hinge torque of the Film V-mount battery & charger protective case

A Film V-mount battery & charger protective case has an outer envelope of 550×395×225 mm, a cavity of 485×335×160 mm and a 4.2 mm wall, with lid and shell joined by a hold-open hinge. The nominal hinge torque is 3.1 N·m: the damping that holds the lid at any intermediate angle after release, neither dropping back nor springing up, and not the closing latch force.

Torque set too low lets a half-open lid creep down onto the mouth; torque set too high makes one-hand lifting stiff and wears the hinge bushing faster, so decay crosses the ≤10% line early after 4400 cycles. The 3.1 N·m figure follows from a 4.2 mm wall, two catches at 360 N each and the lid's split between a plain panel and foam. A Film V-mount battery & charger protective case logs hinge number, angle points and torque on one assembly card, read back by the same number on life retest.

2. Base locating-slot width tolerance

Six locating slots divide the base into cells rated at ≤3.5 kg each, and the ±0.34 mm slot-width tolerance is the key quantity here.

Film V-mount battery & charger protective case white open shell on steel bench, dark foam lid with rectangular reliefs, boxed modules

A Film V-mount battery & charger protective case moulds all six slots in one tool, so width is measured slot by slot rather than one averaged figure for the whole base.

One gasket at 20% compression sits around the mouth and fills the seam when the lid is shut. The seal check shuts the lid to working height, then a pressure-hold run checks whether the joint stays mated, using IP66 only as a reference level rather than a pre-attached label. If mouth flatness shifts after a 1.0 m drop, slot width and compression are measured again.

3. Slot shift on drop retest

The drop criterion for a Film V-mount battery & charger protective case is ≤0.58 mm of slot shift at 1.0 m. Before the drop every slot gets a datum mark and its coordinates are stored; afterwards the same marks are re-read and the largest of the six offsets decides the result.

Torque grade	Slot-width tolerance	Post-drop slot shift
2.7 N·m	±0.34 mm	0.72 mm
3.1 N·m	±0.34 mm	≤0.58 mm
3.5 N·m	±0.34 mm	≤0.58 mm

At 2.7 N·m the half-open lid creeps and the frame loosens its hold, pushing shift to 0.72 mm past the limit; 3.1 N·m with ±0.34 mm slot width holds it to ≤0.58 mm; 3.5 N·m still passes but makes one-hand opening stiff. A Film V-mount battery & charger protective case therefore holds 3.1 N·m as nominal rather than trading more damping for a better number.

4. Torque decay on the cycle rig

The life side of a Film V-mount battery & charger protective case is held to ≤10% hinge-torque decay over 4400 cycles. One cycle opens the lid from shut to 90° and back at a fixed pace, and torque at the 3.1 N·m datum is re-read every 1100 cycles, the four readings forming a decay curve. The angle points reuse the numbers on the assembly card.

Film V-mount battery & charger protective case tan open shell on steel bench, half egg-crate foam lid, kraft packs, two metal latches

A flat early curve that lifts late usually means bushing clearance has opened; four near-linear drops send the check first to loose hinge preload. A Film V-mount battery & charger protective case re-measures slot shift after 4400 cycles too, so the ≤0.58 mm drop criterion is read again at the same checkpoints at the end of life.

Slot number	Per-cell load	Shift retest
C1	3.5 kg	0.42 mm
C2	3.5 kg	0.51 mm
C3	3.5 kg	0.58 mm
C4	3.5 kg	0.36 mm
C5	3.5 kg	0.48 mm
C6	3.5 kg	0.44 mm

Life and drop both clear only if every one of the six cells stays under ≤0.58 mm and the torque loss stays under ≤10%.

5. Per-cell load rejection line for film lots

The lot card for a Film V-mount battery & charger protective case carries slot width, torque decay and per-cell load in three columns, checked together before release. Per-cell load has a hard ceiling of ≤3.5 kg: a cell over it is scrapped, and headroom in a neighbouring cell is not allowed to compensate. Beside those sit the 1.0 m drop shift and the 4400-cycle torque-decay columns, all three passing for release.

Shift reading	Verdict	Action
≤0.40 mm	Pass	Release directly
0.40–0.58 mm	Retest	Re-run drop and recheck slot width
>0.58 mm	Reject	Inspect slot tolerance and hinge torque

Each lot card lists box number, slot number, width reading, angle point, torque reading and shift value for the Film V-mount battery & charger protective case. Drop the width column and a failed shell cannot be traced to a wide tool or a loose hinge. Sampling is layered, and cells beside the mouth flange and hinge seat are pulled into a separate group where scraps tend to cluster. A scrapped box is quarantined instead of joining the next lot, with its neighbours rechecked at the same time. Two retest verdicts in one lot put every slot width back under the dial caliper. Cards are filed by lot and a settled reading is never altered; the 20% gasket compression is re-measured before release and only an in-band value is signed off.

Conclusion

The specification of a Film V-mount battery & charger protective case comes down to three linked readings: ≤0.58 mm slot shift after a 1.0 m drop, ≤10% hinge-torque decay over 4400 cycles, and ≤3.5 kg per-cell load. Together they cover the 3.1 N·m hold-open hinge, the ±0.34 mm slot-width tolerance and the base stiffness of a 4.2 mm wall. JUNZHIJIA keeps slot widths, torque readings and shift values on one lot card, and release is signed per cell.