Xem Studiomeasured geometryLibrary › Stirling engines › Drives & mechanisms ·
Con-rods with Ø3 pin ends, 45 and 60 mm, 8 × 5
What size con-rod connects a syringe piston to a crank? · Hardware · basis: Centres from the solved linkages (Ross yoke 60, alpha V-twin 60, can / LTD 45); Ø3 ends at the Ø3 pins; 5 thick for the syringe piston's 5 mm fork
Long Earth Society build part. The parallel-cylinder alpha, solved. 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
- 3 in table
Notes
- Plain con-rods whose Ø3 end holes turn on Ø3 pins (fit: run). All are 5 thick, the width of the syringe piston's fork slot, with 8 mm wide ends.
- Conrod-45: 45 mm centres, 53 × 8 × 5, for the can and coffee-cup engines.
- Conrod-60: 60 mm centres, 68 × 8 × 5, yoke corner to piston on the Ross yoke alpha.
- Alpha-conrod-60: 60 mm centres on Ø8 ends joined by a 6 wide web, for the alpha V-twin, where both rods share one crank pin and keep 0.8 mm from the syringe barrel wall over a full turn.
Sizes
| file | centres | length | end width | thickness | holes | used on |
|---|---|---|---|---|---|---|
| conrod-45 | 45 | 53 | 8 | 5 | Ø3 | can engine, LTD engine |
| conrod-60 | 60 | 68 | 8 | 5 | Ø3 | Ross yoke alpha |
| alpha-conrod-60 | 60 | 68 | 8 | 5 | Ø3 | alpha V-twin |
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 |
|---|---|---|---|---|
| con-rod ends | Ø3 | Ø3 pins (turn on them) | run | alpha-conrod-* |
| con-rod ends | Ø3 | Ø3 pins (turn on them) | run | conrod-* |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| Wikipedia | Ross yoke | web | CC BY-SA 4.0 (text) |
| Long Earth Society | Engine builds | web, video | LES site |
Free files
★ Free files 3 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json
| conrod-60 | con-rod 60 mm, 8 wide × 5, Ø3 ends (pins turn in them): yoke corner to the syringe piston's fork | STEP · STL |
| conrod-45 | con-rod 45 mm, Ø3 running ends, 8 wide × 5: plain-end rod for the can and coffee-cup engines' syringe pistons | STEP · STL |
| alpha-conrod-60 | con-rod 60 mm, 8 wide × 5, Ø3 plain ends (the pins turn in them; make two): small end in the syringe piston's 5 mm fork | STEP · STL |
Plain text: sheet.txt · JSON: /api/geometry?object=pin-end-con-rods
How it fits
Connects to
Syringe pistonssmall end in the piston's 5 mm fork on a Ø3 pin
Ross yoke a = h = 20 for two parallel syringesconrod-60 on the yoke's corner pins
Alpha V-twin crank disc Ø26, one pin, 16 mm strokeboth alpha-conrod-60s on the one Ø3 crank pin
Rod clevises for a Ø2 or Ø3 rod or a Ø5 tube, 5…conrod-45 on the Ø3-bore crank discsAlternatives
Crank discs for a Ø5 shaft, 10 to 30 mm strokecon-rods with 623 bearing endsAlso needed
Dowel pins, 2–6 mmØ3 pinsIn these build lists
Soda-can gammaA 12 oz can as the displacer cylinder over a tea light, a 10 mL syringe barrel a…LTD coffee-cup engineRuns on a cup of coffee: wide thin displacer, small piston.Alpha V-twin, two 10 mL syringesTwo 10 mL syringe barrels in a 90° V on one crank pin: the V is the 90° phase.Ross yoke alpha, two parallel 10 mL syringesTwo 10 mL syringe barrels side by side on a Ross yoke: a = h gives 90° between t…Mug LTD (sits on a coffee mug)Test-tube marble enginecrank and flywheel at the end.You might also need
Questions
Why is the alpha V-twin con-rod 60 mm long?
A shorter rod swings further and touches the 14.5 mm barrel near its mouth; at 60 mm and 16 mm stroke it clears the wall by about 0.8 mm.
How thick are these con-rods?
5 mm, the width of the 10 mL syringe piston's fork slot.
What pins do the con-rods use?
Ø3 pins; the rod ends turn on them.