Is a thicker wall always better on a robot shipping case?

Answer: No. Past 8.0 mm it gains dead weight, loses cavity space, and drop results often get worse.

How many latches does an 85 kg arm need?

Answer: Four, two per long side, under 400 mm apart; fewer leave the gasket unloaded at mid-span.

Can the case travel without a pallet?

Answer: Yes, if the base has forklift pockets and four corner blocks and the ribs are recalculated for full stack load.

Droplets inside after a sea shipment, is the gasket gone?

Answer: Check position. Droplets on the inner lid are condensation from too little desiccant; droplets low on the side wall suggest weak compression.

For 30 units, can we tool only two sizes?

Answer: Yes. Group the closest masses into one wall grade, cut foam for the largest model, and fill spare cavities with blocks.

Robot Shipping Case Selection: Five Hard Criteria

Quick answer: Fix wall thickness from robot mass and route, size the cushion from the drop height your customer tests, then close the outer dimensions against stacking load and pallet footprint.

Five Criteria for a Robot Shipping Case
From Robot Mass to Wall Thickness
Cushion Depth versus Drop Height
Stacking Load and Pallet Size
Sea versus Road Freight
FAQ

1. Five Criteria for a Robot Shipping Case

Start with one machine, not a catalogue. Four inputs settle everything downstream: mass, centre of gravity, removable parts, and the route the unit travels. Once those are fixed, wall thickness, cushion grade, rib layout and latches all follow.

Mass sets thickness, drop height sets cushion, and both set the cavity that pallet width then pushes back. Scoring a robot shipping case in parallel freezes the shell first, though it should be frozen last.

Criterion	What it changes	Cost of getting it wrong
Mass and centre of gravity	Wall grade, base ribs	Base sag when lifted
Test drop height	Cushion thickness, density	Joints over shock limit
Pallet and hold width	Outer length, foot pads	One tier lost per load
Climate and route	Gasket, desiccant pockets	Condensation, rust

On a robot shipping case, outer dimensions are the expensive revision and wall thickness the cheap one.

2. From Robot Mass to Wall Thickness

Take an 85 kg six-axis arm. With a dynamic factor of 3, peak load lands near 255 kg, shared across four base ribs and four corner blocks. A 1.3 m reach model carries its mass higher, so lateral acceleration adds a side-wall push.

Robot shipping case: close-up of a black case side with one latch half open, egg-crate foam in the lid, pliers and screwdrivers on a workbench

Three wall grades cover most of the range: 4.5 mm below 30 kg, 6.0 mm from 30 to 80 kg, 8.0 mm above 80 kg, all running on an 1850 tonne press at ±0.3 mm. Above 90 kg, add a base cross rib at 12 mm height and 180 mm pitch, or the floor bows when a forklift lifts one side.

Corner blocks take moulded inserts, and lifting points should hold 1200 N without pull-out.

3. Cushion Depth versus Drop Height

Thicker foam is not automatically safer. Every extra millimetre steals cavity space and grows the shell, so fewer units fit per load. Work from the tested drop height, then solve for thickness from mass and contact area.

A robot shipping case for an 85 kg unit at a 0.8 m test drop wants 50 mm of EVA or 55 mm of EPP. EVA is specified at 45 kg/m³ and EPP at 30 kg/m³; absorption at equal thickness is close, and cycle count separates them. Round trips favour EPP, one-way delivery favours EVA.

Second and third axis housings bulge outward on six-axis arms. Add a 15 mm local block over nominal thickness, or they crush first in a whole-unit test.

4. Stacking Load and Pallet Size

A robot shipping case at 120 kg gross stacked four high puts 360 kg of static load on the bottom lid. It all lands on the lid ribs, which must line up with the foot pads above; offset past 30 mm and the lid dishes.

Robot shipping case: grey black case open on white, foam cavities holding a handheld device and a square module, trolley handle and two latches

The pallet is the 1200 × 1000 mm standard, so the base is moulded at 1180 × 980 mm with 10 mm clearance per side. Foot pads sit over the two stringers. A 40HQ gives 2350 mm internal width: two rows, no third.

5. Sea versus Road Freight

A sea route means 25 days at 85% relative humidity with a −5 °C to 45 °C swing. Hold gasket compression near 30%: less leaks, more takes a permanent set and fails the second shipment. Allow 200 g of desiccant per cubic metre of cavity.

Route	Dominant risk	Case-side response
Full load, sea	Humidity, condensation, stack load	Gasket, desiccant, stack step
Road line haul	Vibration, braking	Four-point straps, foam stops
Air freight	Low pressure, handling drops	Relief valve, corner build-up
Multimodal	Repeated handling, thermal cycles	Perimeter blocks, double wall

Road transport needs four straps rated 2000 daN, anchored on moulded bosses rather than latches. Hardware should also survive 48 hours of salt spray; stainless keepers pass, zinc-plated parts show white rust near 24 hours.

Conclusion

The five criteria are a cost curve: early decisions are cheap to revisit, late ones are not. Mass first, drop height second, pallet width last, and the rest is verification. Teams that keep this order tool once, for a robot shipping case that passes the first drop test.

This article discusses only the container (case body) side of specifications and design intent, and does not cover any handling, loading or use of the contents.