When people first see the camper popped out, they assume it's "a big roof top tent". After that, their concern turns to the thin spindly looking poles that support the bed. The two poles are 25/22mm OD tube with approx 1.4mm wall thickness. There is certainly not much to them, but we have had over 250kg on the bed with no issues. The full length hinge on the car side supports half the bed weight, and so the poles only have about a quarter of the load per pole.
The bed poles are probably the most vulnerable part of the camper, so I carry two complete sets of pre-drilled poles, cable tied to the chassis under the car. I also have an extra length of pole, the next size up (28mm?), which can be used as a repair sheath for either the bed or tent section poles. The spare poles weigh next to nothing, and are out of the way.
I use a spiked ground plate like this https://www.allterraingear.com.au/shopexd.asp?id=8750 when camped on soft sand or mud. It stops the poles sinking into the ground, and also stops the poles moving around when there is no weight on the bed. On smooth hard ground or concrete, the bottom of the unweighted poles can slide around if bumped. I have been thinking of making a spring loaded sleeve to go over the bottom of the pole for these instances.
For the tent section corners, in my wisdom, I used rounded "Supapeg" corners. Later I changed the long poles down the length of the canvas from 1.6mm wall, to 3mm wall poles, to reduce the bowing of the 3m long poles when the wet canvas shrinks. This involved a lot of work remelting the Supapeg corner into the smaller ID poles. This also reduced the plastic end on the Supapeg corner down to 19mm, so the corner is probably a smidge weaker than before. I haven't had any issues, but I carry two spare Supapeg corners as these aren't available everywhere.
Next time I would just use c clips to join the corners Plastic Snap Grip Fits In 19mm ID, Over 25mm OD Tube | Caravan Pole & Rafter Parts | CaravansPlus - as per Trayon (photo with grey canvas below). The c-clips are cheaper, lighter, and available everywhere. The resulting square corners would have also made sewing the canvas corners easier. The strength of the tent section structure actually comes from the canvas walls, and there is little front to back movement.
