Editing Psion Series 5mx Hinge Repair (section)

== The printed replacement ==

A complete printable '''inner chassis''' for the Series 5mx is published on MakerWorld by '''ivor.hewitt''' (released 13 June 2026). It is a remix of '''"Psion 5MX — Internal housing / hinge panel"''' by Jon on Printables, which was incomplete; the remix '''adds and corrects the hinges, adds a hole for the battery cover, and updates the holes for M2 screws'''.<ref name="mw">ivor.hewitt, [https://makerworld.com/en/models/2928425-psion-5mx-inner-chassis "Psion 5mx inner chassis"], MakerWorld, released 13 June 2026. Licensed CC BY-NC-SA. Remix of [https://www.printables.com/model/1123397-psion-5mx-internal-housing-hinge-panel "Psion 5MX — Internal housing / hinge panel"] by Jon on Printables. Source for the model's provenance, the described changes, and the four published print profiles and their settings.</ref>

Both models are licensed '''Creative Commons Attribution–NonCommercial–ShareAlike''', so print them for yourself, credit the authors, and do not sell the prints.<ref name="mw" />

=== Which version to print ===

The model is published with '''four print profiles'''. Two of them slice the chassis into a tray plus a separate hinge spine; the other two print it as one piece.<ref name="mw" />

{| class="wikitable styled-table" style="width:100%; text-align:left;"
|+'''Published print profiles'''<ref name="mw" />
! Profile !! Settings !! Time !! Notes
|-
| Sliced, AMS || 0.2 mm layer, 2 walls, 15 % infill || 3.3 h || Chassis and hinge spine as separate parts
|-
| Sliced, no AMS || 0.2 mm layer, 2 walls, 15 % infill || 1.8 h || As above, single material
|-
| '''Single piece''' || 0.2 mm layer, 2 walls, 15 % infill || 3.6 h || '''Recommended'''
|-
| Fine || 0.2 mm nozzle, 0.1 mm layer, 4 walls, 15 % infill || 17.8 h || Slowest, finest detail
|}

'''Print the single-piece version.''' The two-part versions are quicker and easier to print, but they put a joint exactly where the spring wires apply their load — which is the failure you are trying to eliminate.

=== Orientation ===

'''Print it standing up, so the layer lines run along the length of the hinge spine rather than across it.'''

This is the whole point. A part printed flat has its layer boundaries lying perpendicular to the direction in which the spring wires pull on the hooks, and FDM parts are weakest exactly there — the hook does not break, it '''peels off along a layer line'''. Standing the part up puts the extruded filament along the load path instead of across it.

It costs you a longer print and more support material. Take that trade.

=== Material ===

'''PLA is not adequate for this part.''' It creeps under sustained load — which is exactly what a spring wire applies — and it goes brittle with age, reproducing the original failure.

Use one of:

{| class="wikitable styled-table" style="width:100%; text-align:left;"
|+'''Recommended materials'''
! Material !! Why !! Watch out for
|-
| '''PETG''' || Tough, good layer adhesion, forgiving to print, does not creep the way PLA does || Stringing; dry the filament. Slightly flexible, which is fine here.
|-
| '''ABS''' || Strong, stiff, good under sustained load, and can be vapour-smoothed || Warping — needs an enclosure. Ventilate.
|-
| '''PC (polycarbonate)''' || The strongest and stiffest of the three, and the best choice if your printer can manage it || High nozzle and bed temperatures; needs an enclosure and dry filament.
|}

Print '''hot enough for good layer adhesion''' rather than for a pretty surface finish. This is a structural part; interlayer bonding is the whole specification.

Consider raising the wall count above the profile's default of 2 — '''3 or 4 walls''' puts more solid material into the thin hook features, at very little cost in time.

=== Fasteners ===

The model's holes are '''sized for M2 screws'''.<ref name="mw" /> Recover the original screws if they are in good condition; otherwise M2 machine screws of the right length will do. '''Do not over-tighten''' — the original service manual warns that the case screws purchase into the chassis moulding and strip easily, and that is even truer of a printed part.<ref name="s5sm" />