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Creative & Custom LED Displays Bend limits for flexible LED cylinder wraps are set by module size, not pixel pitch. 240×120mm modules reach a 764mm minimum outer diameter; 320×160mm modules need 815mm. Columns below those limits cannot use standard flexible modules without risking copper-trace micro-cracks. This guide explains the geometry, how to choose module size, and what to do when the pillar is too small. Part of our Cylinder LED Buying Guide cluster.
- 240×120mm flexible modules → min Ø764mm finished cylinder diameter.
- 320×160mm flexible modules → min Ø815mm finished cylinder diameter.
- Limits come from PCB bend radius and copper-trace fatigue — not from pitch (P1.5–P4 share the same module-size limits).
- Measure finished wrap diameter (pillar + frame clearance + module thickness), not bare concrete alone.
- Below 764mm: do not force standard flex modules. Request a feasibility drawing within 48 hours — or change form factor. Product page: /cylinder-led-screens/.
The Two Hard Numbers: 764mm and 815mm
DOIT VISION cylinder builds use flexible modules from the same families documented on our Flexible LED line. For cylinders, the published minima are:
| Module | Min Outer Ø | Circumference at Min Ø |
|---|---|---|
| 240 × 120mm | 764mm | ≈ 2.40m (π × 0.764) |
| 320 × 160mm | 815mm | ≈ 2.56m (π × 0.815) |
These numbers are finished outer diameters of the LED surface — the diameter a viewer measures after modules are mounted. Absolutus Lisbon ran Ø1.53m, well clear of both limits. Specs and options: Cylinder LED Screens.
Why Module Size Sets the Limit (Not Pitch)
A flexible module is a PCB with LEDs and copper traces that must curve around a cylinder. Bend radius is limited by how far those traces can deform without micro-cracking. Larger modules (320×160) span a longer chord — they need a gentler curve, hence a larger minimum diameter.
Pixel pitch (P1.5 vs P4) changes LED density on the same board outline. It does not change the physical board size that wraps the column. That is why P1.5 GOB and P4 outdoor builds share the same 764 / 815mm floors when they use the same module footprint.
Ring and circular products have different geometry (band loops and flat discs) — see Ring Buying Guide and Ring vs Circular vs Cylinder. Do not apply ring “minimum outer diameter” rules to cylinders.
What Happens If You Go Smaller
Forcing a standard flexible module below its rated diameter typically fails in this order:
- Install-day resistance — modules fight the curve; magnets seat unevenly; seams open.
- Copper-trace micro-cracks — dead pixels or dead rows appear days to weeks after power-on.
- Warranty void — damage from over-bending is not a factory defect; it is a specification error.
If the finished wrap diameter cannot clear 764mm (240×120) or 815mm (320×160), stop the quote process and open a feasibility review. Do not “try a sample module on site” as a substitute for calculation — sample success does not prove long-term trace reliability.
How to Measure On Site
Integrators often measure bare concrete and miss the finished diameter. Use this sequence:
- Pillar diameter at multiple heights — check ovality (max − min).
- Cladding / plaster / fire wrap thickness that will remain under the LED frame.
- Frame clearance — steel cage outer radius above the pillar surface.
- Module depth — finished LED face sits outside the frame.
Finished Ø ≈ pillar Ø + 2 × (cladding + frame build-up + module thickness). Compare that number to 764 / 815 — not the raw pillar alone.
For wrap vs freestanding form factor after diameter clears the floor, read Column Wrap vs Can-Shape.
Choosing 240×120 vs 320×160
- → Min Ø 764mm — use when columns are tight
- → More modules per circumference — slightly more seams to manage
- → Preferred when finished Ø sits between 764 and ~850mm
- → Min Ø 815mm
- → Fewer modules per loop — faster hang on large columns
- → Common for mall atriums and taller wraps (e.g. Absolutus-scale)
Pitch and GOB are independent decisions: public-access fine pitch (≤P2.0) should still specify GOB regardless of module footprint. Absolutus Lisbon used P1.5 GOB at Ø1.53m — case study.
When the Pillar Is Too Small
If finished wrap diameter cannot clear 764mm, options are limited and should be decided before budgeting:
- Increase finished diameter — thicker frame build-out or cladding build-up so the LED face sits at ≥764mm (confirm architect / landlord).
- Move to can-shape freestanding totem nearby if the pillar itself cannot grow — see wrap vs can-shape.
- Change creative shape — ring halo or circular wall disc may fit the brief better than a forced micro-column. Start at Creative LED.
- Custom engineering — non-standard module or rigid facet solutions exist in rare cases; they are not the default Flexible LED cylinder BOM and need explicit engineering approval.
Send column diameter photos for a feasibility drawing within 48 hours — do not assume a “custom small cylinder” is a stock SKU.
Spec Checklist
-
Finished outer diameter calculatedPillar + cladding + frame + module depth. Compare to 764mm (240×120) or 815mm (320×160).
-
Module footprint selectedTight columns favour 240×120; larger atriums often use 320×160.
-
Pitch and GOB decided separatelyP1.5–P4 by viewing distance. Public-access ≤P2.0 → GOB.
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Ovality and services documentedMax/min diameter, fire risers, access panels — before CAD.
-
Below-limit plan agreed if neededBuild-out, can-shape, or alternate creative shape — not forced over-bend.
Buying sequence: Cylinder Buying Guide. Install: Installation Guide.
Send pillar diameter (with cladding notes) and target height. We return a feasibility drawing within 48 hours and CAD within 72 hours if the diameter clears the module limit.
