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Parallel ruler with crossed arms and slots
How does a parallel ruler stay parallel? · Hardware · basis: Xem Studio design following Brown No. 324 (1868)
Also called: parallel ruler, navigation parallel rule, drafting parallel ruler, regla paralela, Parallellineal
Exact dimensions. True size, with no printing tolerance added.
- sizes
- 3 in table
Notes
- Two straight-edges joined by two equal crossed arms pinned at their middles; each arm is pinned to one blade and slides in a slot of the other. The pinned ends are always one above the other, so the blades stay parallel and square to each other at any opening.
- Built from two 200 mm blades and two 80 mm centre-hole links: drawn open 40 mm; the slot lets it open from 0 to 55 mm.
- Brown's No. 324 (compound parallel ruler, crossed arms with slot-and-pin).
- Parts (each has its own page): parallel-ruler-blade-200, centre-hole-link-80, dowel-pins-metric.
- Brown's movement No. 324 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.
Parallel ruler with crossed arms and slots size chart
| parameter | value |
|---|---|
| blades | 2 × 200 × 20 × 5 mm |
| arms | 2 × 80 mm, crossed at the middle |
| opening | 0–55 mm (drawn 40) |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| Henry T. Brown (1868, public domain) | Five Hundred and Seven Mechanical Movements — scan on archive.org | web | Publisher's page; dimensions are facts |
| 507movements.com | Brown's movement No. 324: figure, his text and an animation | web | Publisher's page; dimensions are facts |
Free files
★ Free files 1 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json
| parallel-ruler-crossed-arms-mechanism-assembly | Assembled mechanism, all parts placed at one pose (STEP keeps each part separate) | STEP · STL |
https://xemstudio.com/mcp to Claude, ChatGPT, Cursor or any MCP client (free, no account, one minute) and it can look up exact sizes, mating fits and free STEP/STL from every chat.Plain text: sheet.txt · JSON: /api/geometry?object=parallel-ruler-crossed-arms-mechanism
Fits with
Questions
How does a parallel ruler stay parallel?
Two straight-edges joined by two equal crossed arms pinned at their middles; each arm is pinned to one blade and slides in a slot of the other. The pinned ends are always one above the other, so the blades stay parallel and square to each other at any opening.