====== Arc ======

{{tag>assembly structure shelter}}

//A tube-and-connector arch — a passage, a gateway, or shade across a span. Built flat from the 1,33 m module, then tilted upright.//

  * **Type:** Structure
  * **Status:** In use
  * **Primary function:** arch / passage / shade

===== 1. At a glance =====

^ Specification      ^ Value          ^
| Footprint          | 7,98 x 1,33 m  |
| Height             | 3,99 m         |
| Volume             | 42,29 m3       |
| Total weight       | 125,0 kg       |
| Assembly time      | 1h |
| People needed      | 2 |
| Tools              | Hammer (optional, for pins) |

===== 2. 3D model & steps =====

{{url>https://mobil.brussels/wiki/three-viewer/viewer/index.html?p=arch 100%,720px noborder noscroll}}

//If the model doesn't load, [[https://mobil.brussels/wiki/three-viewer/viewer/index.html?p=arch|open it in a new tab]].//

===== 3. Parts (bill of materials) =====

Everything you need to build one arc. All tubes diameter 50 x 2 mm wall. Click a part for specs and handling.

^ Part ^ Qty ^ Spec ^
| [[mobil:parts:core_kit:short_tube|Straight tube]]      | 44 | 1329,4 mm |
| [[mobil:parts:core_kit:long_tube|Diagonal tube (45)]]  | 31 | 1880,1 mm |
| [[mobil:parts:core_kit:t_connector|T-connector]]       | 56 | 2 per connector node |
| [[mobil:parts:core_kit:x_connector|X-connector]]       | 28 | 1 per connector node |
| [[mobil:parts:core_kit:locking_pin|Locking pin]]       | .  | 1 per tube-connector joint |
| [[mobil:parts:hub_elements:panel_square|Panel]]        | 8  | 1329,4 x 1329,4 mm //(panel type to confirm)// |

  * **Connector nodes:** 28 (each = 2x T + 1x X)
  * **Tubes total:** 75 - **tube length:** 116,78 m
  * **Tube weight:** 95,1 kg - **connector weight:** 30,0 kg - **total:** 125,0 kg

//Source: MoBil builder. Locking-pin count and panel type to confirm.//

===== 4. Assembly =====

The arc is built flat as the profile of the arch, then tilted upright. Each node = the [[mobil:assemblies:structures:connector|connector]] assembly (2x T + 1x X), joined by tubes.

  - **Lay out the contour.** Set connectors flat on the ground in the arch profile.
  - **Connect with tubes.** Join the nodes.
  - **Build up.** Add all vertical and diagonal tubes, with connectors on top.
  - **Close the top surface.** Cap with connectors.
  - **Tilt 90.** Stand the arch upright on its hinge.
  - **Add panels to the bases.**

//Each step maps to a stage in the viewer above.//

===== 5. Safety & correct use =====

==== Build safety ====
  * Pinch points at every connector - keep fingers clear when seating joints.
  * Don't hammer pins with the frame unsupported; seat the joint by hand first.
  * Tilting the span upright needs enough hands - never lift it short-handed.

==== Use & load limits ====
  * **Max vertical load (stage/roof):** . kg //(to define / test)//
  * **Do not climb** the frame unless rated and ballasted.
  * **Wind:** above . km/h, remove banners/roof and ballast or take down. //(define - sail-bearing span)//
  * Never leave a tall configuration up unattended in changing weather.

==== Ballast / anchoring ====
  * Footprint anchoring with [[mobil:parts:accessories:water_weight|water weights]] at the base corners for any raised or sail-bearing configuration.
  * [[mobil:parts:accessories:ropes|Ropes]] to fixed points where available.
  * Minimum ballast: 15 kg per corner ont he ground.

===== 6. Takedown & storage =====

  - Remove add-ons and ballast first.
  - Tilt the frame back down flat before breaking joints.
  - Pull top pins, lift off the top surface.
  - Pull verticals and diagonals.
  - Break the base. Nodes can stay assembled for next time, or break to flat-pack.
  * **Packs into:** [[mobil:parts:logistics:normal_bike_trailer|normal bike trailer]] (tubes + euroboxes for connectors).
  * Store dry. Check pins aren't bent before repacking.

===== 7. Compatible add-ons =====

What this arc accepts:

  * [[mobil:assemblies:modules:roof|Roof]]
  * [[mobil:assemblies:modules:banners|Banners]]

===== 8. Media & credits =====

  * Photos - Drawings - Exploded diagram
  * Linked: [[mobil:assemblies:structures:connector|Connector]] (the core joint)

//Designed by . - Year . - Iteration . - Last updated: .//