STEPS for Attic Spiral Staircase

[nelsonic]

The Metal Frame of the Attic Spiral Staircase has been completed and installed: #30 (comment)
Next we need to make all the stairs for the frame so that it's actually useful as a staircase.

These measurements were taken using a laser measuring device:

In all cases I took the measurement twice. In most cases the measurement was identical. In some there was a 1mm diff.
Even though I scribbled them down, they are accurate.

Made the first step on the Laser Cutter:

Used the high(er) density Betula (Birch) Plywood from MC Madeiras and it took 8 passes of the laser at 80% intensity and 20mm/sec speed. The Leroy Merlin Plywood is Choupo (Populus alba, commonly called Silver Poplar) is much softer so it only requires two passes of the Laser cutter and that means there is far less "burn out".

I could cut the remaining steps on the Laser from (Leroy) Poplar Ply
The biggest sheet of pre-cut Leroy Ply we can fit in our car is 1200 x 600mm.
However most of the measurements listed above are too wide to fit in a 1200 x 600mm sheet of ply.
https://www.leroymerlin.pt/Produtos/Madeiras-acrilicos/Paineis-construcao/Contraplacado/WPR_REF_11034282

So we would end up wasting a lot of material (money).
For example: Cutting Step #1 (790mm x 330mm) out of the 1200 x 600mm would look like this:

Steps 3,4,7,8,9,10 exceed the width of a 600mm board therefore it's not possible to cut them.

Luckily, Leroy has a free cutting service that we can use if we buy sheet materials in store.
The biggest sheet they sell is 2440 x 1220 mm
https://www.leroymerlin.pt/Produtos/Madeiras/Paineis/WPR_REF_18896675

Note: the product listing says 2500X1220X15MM but we know that the 2440mm is the correct length. 🙄

I feel it will be more effective to get all the steps cut by the bandsaw at Leroy
and then just do the finishing in our workshop @home.

Todo

• Create an Inkscape sketch of the 2440 x 1220 mm board
• See how many of the 14 steps can fit in each board.

  this is an optimisation exercise that can be done manually as a "puzzle" or automated in code
  I estimate that we will be able to get all the steps out of 3 boards (but I might be wrong)

• Print the plywood sheet cutting lists to take to Leroy
• Take paper sheets to Leroy for cutting
• Transport cut steps back to @home for assembly
• Assemble ASSEMBLE Attic Spiral Staircase Steps #136
• Finish?
• Install

@iteles as discussed verbally, (adding info here for completeness):

1. We need two of each step as the 15mm ply flexes when stood on in the middle, so we want to sheets to make up 30mm
2. For the triangular steps (3,4,7,8,9,10) we need to add 3mm to the width & height in order to be able to cut the rectangle and make two triangles. The thickness our circular saw blade is actually 2.2mm but I prefer to round up and then sand/route down the excess.

[nelsonic]

3 Boards ready to print and take to be cut at Leroy tomorrow:

1. https://github.com/dwyl/home/blob/master/attic/attic-stairs-board-1.svg
2. https://github.com/dwyl/home/blob/master/attic/attic-stairs-board-2.svg
3. https://github.com/dwyl/home/blob/master/attic/attic-stairs-board-3.svg

[nelsonic]

Done. ✅ see: #136 (comment)