Mechanical expanding cardboard lamp - This way up!

Step 9 Cut the uprights

Mark out the plan and cut out the four uprights, but don't cut the slots for the base connectors yet, or the centre slot. And don't worry about the accuracy of the curve on the plan, it isn't significant. Each upright won't have been labelled yet, so don't cut the "punch on xIN" holes on the plans yet.

To make sure the slots were all cut the same, I punched the top hole and the one at the bottom of the slot, and threaded all four uprights onto a pair of skewers. Then I used a long bladed knife to carefully saw out each slot in all four uprights at once. (pic) Slide a piece of scrap board into the slots to make sure it's true.

Cut the central slot in each upright slightly wider than the holes, so it holds a bamboo skewer loosely - a bit of play here won't hurt, and it's better to have it loose than jamming because it's tight.

The shape of the uprights are identical, but their wiring is different. Number them 1 to 4, and mark each side "in" or "out" for which direction it will face (see pic). Turn each "IN" side upwards, and lay your plan on top, and mark the positions of the holes for each upright. Don't punch right through now, that'll come later when installing the wiring.

Cut out the two base connectors. These need folding pretty hard (see step 7 for hints about folding), but are otherwise simple.

Test the base
Do a test fit when you've got all your parts, with your uprights in their proper order and orientation, 1 to 4, left to right. You should find that there's some "smudginess" in the fit of your parts, but nothing that a bit of light twisting won't fix. Corrugated cardboard is good like that, and the base will be very solid once done. Put skewers through the holes and slots to make sure they all line up.

Remember if you find that your parts don't fit well (for whatever reason), you can always just glue them rather than rely on a friction fit. But do it later, when all the hardware is installed.

Cut out the gondola. This is the basket that you will fill with your heavy counterweight material. The design I have given you uses glued panels, but the original was simply folded and locked using the skewer that it hangs from. There's no significant difference: I was just trying to show off. I feel a bit embarrassed now. There are no real engineering factors here, but don't underestimate how much space you'll need for the counterweight material (higher capacity is better).

You will be pleased now you have something structural rather than just a pile of sticks. More tea - you've earned it, soldier.