Build guide

Geodesic dome hub connectors

The hub is where a dome is won or lost. The struts are simple sticks; the connector is what has to resolve five or six of them meeting at an angle that is different at almost every vertex. Pick the wrong hub system and you will spend the build fighting tolerance you could have designed out.

The three approaches that actually get built

Flattened and drilled tube

The cheapest hub is no hub at all: flatten the last few inches of each steel tube, bend it to the required angle, drill one hole, and bolt the whole cluster together at the vertex. This is the classic EMT conduit dome. Material cost is almost nothing beyond the tube and a bag of bolts, and the tools are a hammer, a vice, and a drill.

The catch is that the bend angle is not the same at every hub, and eyeballing it accumulates error around the dome until the last struts do not want to meet. That is exactly the kind of error a per-strut bend template removes.

Steel or plywood hub plates

A hub plate is a flat disc or star with an arm for each incoming strut, set at that vertex's true angles. Struts bolt to the arms. It costs more in material and requires cutting the plates, but it is far more forgiving during assembly and far more repeatable — the angle lives in the plate rather than in your bending technique.

This is the system that benefits most from proper fabrication files, because a plate cut at a generic angle defeats the whole point of using plates.

Panelized (no discrete hub)

Panelized construction skips struts and hubs entirely: each triangle is built as a framed panel, and panels bolt to each other along their edges. The connection problem becomes an edge-bevel problem instead of an angle-cluster problem. It is the most weatherproof approach and the friendliest to sheet coverings like plywood or polycarbonate, at the cost of more cutting and more material.

Choosing between them

Lowest cost, temporary or seasonal — flattened tube. A shrink-wrap or film-covered dome that comes down in spring does not need more.
Repeatable, semi-permanent — hub plates with timber or tube struts. Easier to assemble accurately, easier to disassemble and re-erect.
Weathertight, insulated, permanent — panelized. If it is going to be a cabin or a heated greenhouse, the edge-to-edge seal is worth the extra work.

Why generic hub plans disappoint

Most dome hub plans sold as static PDFs give you one plate drawing and leave you to adapt it. But a dome does not have one hub geometry — a 3V 5/8 sphere has several distinct vertex types, each with its own arm count and its own set of angles between arms, and the base ring is different again where the sphere was truncated.

DomeFab generates DXF hub plates at the true per-hub angles for your specific dome, not a representative one, along with per-strut drill and bend templates for flattened-tube builds and panel templates for panelized ones. Those go to a laser cutter, plasma table, or CNC router directly — or get printed at 1:1 and used as a drilling guide.

DomeFab plans are informational. They are not a stamped structural analysis and are not intended for permit submission.