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Journal · The Long Bench log

Field notes from the bench, dated in the week they happened.

This page is the shop-floor log: what was on the bench, what the room was doing to it, and what gave way. Entries are written in the week they happen, conditions included, and they are not rewritten into procedures afterwards.

Repeatable, tested steps belong to the guide library — 581 articles, each one built, broken and rebuilt before it was written up.

Read the latest field note Browse the guide library

Reverse chronological

Newest note first. Older entries stay where they were written; corrections arrive as dated appendices underneath, never as silent edits.

Bench conditions attached

Every entry carries the ambient temperature and humidity it was written under, taken at the bench at the time — not estimated later from memory.

Not a how-to archive

Dated observations only. The repeatable procedures live in the guide library, and they stay there across reprints.

Standing notice

The journal records what happened at the bench. Tested procedures are read in the guide library.

What this page holds

  • Dated field notes from the shop floor, newest first, under running headers such as “What broke this week”.
  • The ambient temperature and humidity recorded at the Long Bench when the note was written.
  • Failures that did not make it into a guide, and fixes that are still being watched.
  • Errata pointers: when a reader finds something we missed, the date and the change are appended to the original article.

What this page does not hold

  • Step-by-step procedures. A note here describes one bench on one day; a guide has been rebuilt by a second person from the written steps alone.
  • Tolerances presented as targets. Our numbers describe one printer, one material batch, one room.
  • Comments, replies or messages. Nothing on this page is transmitted or stored.

Looking for something you can repeat on your own bench? Browse the guide library — that is where the procedures live.

Running header

What broke this week

Newest note first. Each entry is dated, carries the ambient temperature and humidity it was written under, and stops there — no steps, no procedure, no promises about your printer.

Print farm · Machine 3

The drag chain ate its own thermistor ribbon

21.8 °C · 41% RH · PETG batch 22-B · 0.4 mm nozzle

Machine 3 had been running the same enclosure panel all week. The thermistor ribbon was zip-tied to the drag chain at the factory anchor point, and by Thursday the tie had worn a 1.2 mm notch in the insulation. The print did not fail for a print-quality reason — the thermistor reading dropped out mid-layer and the controller threw a thermal error at layer 214, which is the only reason we caught it before the conductor went through.

The fix was a printed strain-relief clamp that pins the ribbon 40 mm back from the chain anchor, so the movement happens in the slack instead of at the tie. Roughly 190 printing hours later the notch has not grown. It is on the bench card for entry 118 and will move into the guide library once a second pair of hands reproduces the clamp from the written steps alone.

Hand tools

A torque wrench that had drifted 0.6 Nm against the reference

20.9 °C · 46% RH · 5 Nm wrench, checked against a beam reference

The wrench had been living in the unheated side of the shop since November. Checked against the beam reference it read 0.6 Nm high at 5 Nm — enough to matter on the M3 hardware we use for fixture clamps, and enough to strip a printed boss if you lean on it.

It came back into agreement after 40 minutes at room temperature, which is the honest and slightly annoying answer: the tool was not broken, it was cold. Storage has moved indoors. The original tool guide keeps its text; this note is the appendix.

Finishing

Humidity turned a fast-drying topcoat matte overnight

18.4 °C · 61% RH · same tin, same brush, same technique

The three-coat test panel was in spec at five in the afternoon. By morning the topcoat had bloomed matte across the lower half. Same tin, same brush, same technique — the only variable we can point at is the room sitting at 61% RH overnight while it cured.

Panels sprayed the following week at 43% RH cured clear. The tin was not the problem and has been reinstated. Written down so the next person does not re-blame the finish.

Fixtures

The jig that needed a shim, and the shim that stayed

19.2 °C · 38% RH · MDF fence, 0.28 mm brass shim

MDF is not stable and this jig proved it again: 0.3 mm of bow across the 300 mm fence after a fortnight in the dry shop. Rather than remake the fence we shimmed it with a strip of 0.28 mm brass, bedded on the low side.

Twelve weeks on, a feeler gauge still will not take 0.05 mm anywhere along the joint. Documented as a dated appendix under the original fixture article, with the original text left standing so you can see what changed and when.

Data pulse

Bench conditions

The ambient readings that sat behind the entries above, and the ones still being logged. Each row is one bench card at the Long Bench, read off the thermometer and hygrometer hanging over the bench.

Readings taken at the time of the entry. They describe one shop, not a controlled environment — compare them against your own conditions rather than treating them as targets.
Date Ambient Humidity In play What it affected
12 Mar 2026 21.8 °C 41% RH PETG 22-B, Machine 3 Ribbon wear inside the drag chain; thermal error at layer 214
5 Mar 2026 20.9 °C 46% RH 5 Nm torque wrench 0.6 Nm drift on cold tooling; recovered at room temperature
27 Feb 2026 18.4 °C 61% RH Fast-drying topcoat Matte bloom on the lower half of the test panel overnight
19 Feb 2026 19.2 °C 38% RH MDF jig fence, brass shim 0.3 mm bow measured across a 300 mm fence after two weeks

Standing guest column

Someone else’s bench caught what ours did not

“I rebuilt the enclosure guide from the written steps alone, in a cold garage, with nobody to ask. The hinge clearance listed as 0.4 mm worked at 22 °C and bound shut at 9 °C. Two lines of that guide are wrong in winter, and I have written down which two.”

Guest column · a reader who reproduced a published guide and found the part the authors missed

This is the most useful kind of entry the journal gets, and it is why the two-hands rule exists: a build is published only after a second person reproduces it from the written steps without asking the original author anything. When a reader’s bench catches something ours did not, the note lands here first, then becomes a dated appendix under the original article. Corrections are sent through the reading-and-corrections channel on the contact page.

Two duties, two shelves

Dated notes are read here. Tested procedures are read in the guide library.

The journal holds what happened on the bench in the week it happened, conditions and all. When a build survives the second-hands rebuild, and any step that needed verbal clarification has been rewritten, it graduates into the guide library — 581 articles, all of them keeping the addresses they have always had.

Read the latest field note Browse the guide library

Reference tables — tolerances, fastener equivalents, wire gauge and the cost-per-part worksheet — sit in resources.