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Crank webs (bar cranks), Ø5 bore, 10 to 30 mm stroke
What is a crank web and how do two make a crankshaft throw? · Hardware · basis: Bar crank 6 thick with a Ø22 × 12 hub, Ø5 bore, Ø3 pin at stroke / 2 and a counter-mass lobe
Long Earth Society build part. Balanced cranks for the 2 in gamma. The engines
Exact dimensions. Every file is drawn at true size with no printing tolerance. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your printer's or process's clearance before making the part. Mating features
- sizes
- 5 in table
Notes
- A 14 mm wide bar 6 thick with a Ø3 pin hole at half the stroke, a Ø18 counter-mass lobe centred 6 mm behind the axis, and a Ø22 hub 12 tall with a Ø5 bore.
- A radial Ø2.5 hole (M3 tap drill) 9 mm up the hub locks it to the shaft.
- Two webs and a Ø3 pin make a throw in the middle of a shaft, so the con-rod sits between two bearings.
- Overall length 27, 29.5, 32, 34.5, 37 for 10–30 mm stroke; 22 wide.
Sizes
| file | stroke | pin offset | overall | hub |
|---|---|---|---|---|
| crank-web-stroke10 | 10 | 5.0 | 27 × 22 × 12 | Ø22 × 12 |
| crank-web-stroke15 | 15 | 7.5 | 29.5 × 22 × 12 | Ø22 × 12 |
| crank-web-stroke20 | 20 | 10.0 | 32 × 22 × 12 | Ø22 × 12 |
| crank-web-stroke25 | 25 | 12.5 | 34.5 × 22 × 12 | Ø22 × 12 |
| crank-web-stroke30 | 30 | 15.0 | 37 × 22 × 12 | Ø22 × 12 |
Mating features
Drawn at the exact size. Open press, slide, run and socket features by your process's clearance; leave designed gaps and clamp fits as drawn.
| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| web bore | Ø5 | Ø5 crankshaft (M3 grub) | slide | crank-web-* |
| web pin hole | Ø3 | Ø3 crank pin | press | crank-web-* |
| web grub hole | Ø2.5 | M3 tap drill | designed | crank-web-* |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| Wikipedia | Engine balance | web | CC BY-SA 4.0 (text) |
| Wikipedia | Crankshaft | web | CC BY-SA 4.0 (text) |
| Long Earth Society | Engine builds | web, video | LES site |
Free files
★ Free files 5 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json
| crank-web-stroke10 | crank web (bar crank) 10 mm stroke, Ø5 bore with set-screw hub, Ø3 pin; two make a full crankshaft throw | STEP · STL |
| crank-web-stroke15 | crank web (bar crank) 15 mm stroke, Ø5 bore with set-screw hub, Ø3 pin; two make a full crankshaft throw | STEP · STL |
| crank-web-stroke20 | crank web (bar crank) 20 mm stroke, Ø5 bore with set-screw hub, Ø3 pin; two make a full crankshaft throw | STEP · STL |
| crank-web-stroke25 | crank web (bar crank) 25 mm stroke, Ø5 bore with set-screw hub, Ø3 pin; two make a full crankshaft throw | STEP · STL |
| crank-web-stroke30 | crank web (bar crank) 30 mm stroke, Ø5 bore with set-screw hub, Ø3 pin; two make a full crankshaft throw | STEP · STL |
Plain text: sheet.txt · JSON: /api/geometry?object=crank-webs-5mm-bore
How it fits
Goes in or on
Crankshafts Ø3, Ø5 and Ø8 with full-length D-flatØ5 bore, M3 grubConnects to
Connecting rods 30 to 80 mm centres with 623 pockets623 on the pin between the websAlso needed
Crank and wrist pins Ø3 × 12, 16, 19, 20 and 23Ø3 pin between two websYou might also need
Questions
Disc crank or crank web?
A disc is one part with the con-rod outboard. Two webs make a centre throw so the con-rod runs between two bearings: stiffer, for two-cylinder or beam engines.
What pin joins two crank webs?
A Ø3 pin through both pin holes; the con-rod's 623 turns on it between the webs.