Mounting Block — Risk Analysis
This page estimates and assesses the risks of the OpenPoleMount mounting block, its failure modes, and how they are mitigated. It follows the spirit of a lightweight ISO 14971-style analysis, scaled to what the part actually is: a passive, non-powered, 3D-printed pole clamp.
Scope & nature of the part
OpenPoleMount is general-purpose mounting hardware — not a medical device. It has no electrical, chemical, or software function, no patient contact, and no role in delivering, controlling, or supporting medication or therapy. The single hazard category is mechanical: the secure retention of whatever is mounted on a pole. See the Safety & Disclaimer.
Summary of residual risk
The dominant risk is a mounted object shifting or falling if the mount is mis-printed, overloaded, or mis-installed. This is mitigated by conservative, documented print settings; a stated load rating; a simple installation procedure; and — demonstrated by destruction testing — a safe, visible, non-catastrophic failure mode that retains residual grip rather than releasing suddenly. With the recommended settings and correct installation, residual risk is low for the intended general pole-mounting use.
Load rating
Recommended working load: up to ~1.4 kg (3 lb) per mount, as a conservative starting point at the recommended print settings. Actual capacity depends on material, print quality, and pole fit — verify safe support of your own load before relying on it.
Hazard / risk table
| # | Hazard | Cause | Potential effect | Mitigation |
|---|---|---|---|---|
| 1 | Mount slips or rotates on the pole | Thumbscrew under-tightened; pole diameter outside the channel's range; dusty/greasy pole | Mounted object shifts or drops | Hand-tighten + ¼ turn; match the pole diameter (resize the model if needed); clean the pole. Grip is by printed channel geometry, not just friction. |
| 2 | Overload | Object heavier than the ~1.4 kg rating; shock/jerk loads | Part deformation or failure | Respect the stated load rating; avoid impact loads; use PETG and/or higher infill for heavier objects. |
| 3 | Thumbscrew over-tightened to failure | Sustained force far beyond hand-tight | Crack propagates and the thumbscrew punches through the side wall | Do not over-tighten (documented in the Assembly Guide). Testing shows this requires force no normal user applies, the pole channel stays intact, failure is immediately visible, and the broken mount retains residual grip. |
| 4 | Weak print | Wrong infill pattern (lines/grid instead of 3D honeycomb), too few walls, under-extrusion, layer delamination | Reduced strength; premature failure under load | Follow the Print Guide minimums (6 walls, 2 mm top/bottom, ≥35 % 3D honeycomb); inspect each print; flex-test by hand before use. |
| 5 | Wrong print orientation | Block printed with layers parallel to the clamp load | Layer-line splitting under clamping force | Print the block with the pole channel vertical (layers perpendicular to load), thumbscrew flat — per the print guide. |
| 6 | Material creep / heat softening | PLA under sustained load, or in a warm environment (PLA softens ~60 °C) | Slow deformation / loss of grip over time | Use PETG for sustained-load or warm conditions; inspect periodically; do not place near heat sources; re-check tightness. |
| 7 | Pole damage | Excessive clamping torque | Marring of the pole | The printed clamp face is far gentler than metal hardware by design; use only the specified torque. This is a reduced risk versus metal clamps. |
| 8 | Undetected degradation | UV exposure, repeated stress cycles, ageing filament | Gradual weakening | Failure mode is visible, not hidden (see testing); inspect before each use; reprint if cracked, warped, or flexing. |
Evidence: destruction testing
A deliberately under-spec print (below recommended minimums) was tested to destruction on 2026-06-09. Key results:
- It never failed under normal load — the failure point was only reached under extreme, sustained thumbscrew over-tightening far beyond any real use.
- Failure was localised to the thumbscrew side wall; the pole channel and body stayed intact.
- The failure was immediately visible — no hidden or gradual weakening.
- The broken mount still held on the pole (residual grip) — a mounted object would not suddenly drop; there is time to notice and act.
The recommended settings are ~2× the wall thickness of that worst-case test print, giving a generous margin. Full write-up and video: Strength Testing.
Mitigation & maintenance summary
- Print at or above the recommended minimums, in the correct orientation.
- Inspect each printed part; reject any with cracks, warping, delamination, or flex.
- Match (or resize to) your pole diameter.
- Hand-tighten plus a quarter turn — do not over-tighten.
- Stay within the ~1.4 kg load rating; use PETG for heavier or warmer use.
- Re-inspect and re-check tightness periodically; reprint if any damage appears.
Points of failure (single-point summary)
| Point of failure | Consequence | Detectability | Net risk |
|---|---|---|---|
| Thumbscrew side wall | Localised crack under gross over-tightening | Immediately visible; residual grip retained | Low |
| Pole channel grip | Slip if under-tightened or wrong pole size | Visible/felt on install and load test | Low with correct install |
| Print integrity | Weak part if settings/orientation wrong | Detectable by inspection and hand flex-test | Low with adherence to guide |
This analysis is provided for informational purposes only and does not constitute engineering certification or regulatory approval. See the Safety & Disclaimer.