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Tri-clamp con-rod: 58, 70 and 95 mm centres with 623 pockets
How long is the con-rod for a 2 inch tri-clamp piston? · Hardware · basis: Rod centres = wrist-pin height + crank height + stroke/2 (1.5 in 58, 2 in 70, 3 in 95 mm), keeping the rod angle under 11°
Long Earth Society build part. Full-bore pistons for the tri-clamp beta and alpha engines. 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
- An I-section connecting rod with a Ø10 pocket for a 623 bearing at each end: the small end on the piston's Ø3 wrist pin, the big end on the Ø3 crank pin.
- Centres 58 / 70 / 95 mm for the 1.5 / 2 / 3 in piston and crank frame. 5 mm thick, Ø14 ends, 10 mm wide web recessed 1.2 mm each side (2.6 mm web).
- Overall 72 / 84 / 109 mm long. At bottom dead centre the piston skirt is flush with the ferrule face.
Sizes
| spool_in | centres_mm | overall_len_mm | thickness_mm | end_od_mm | pockets |
|---|---|---|---|---|---|
| 1.5 | 58 | 72 | 5 | 14 | 623 (Ø10) both ends |
| 2 | 70 | 84 | 5 | 14 | 623 (Ø10) both ends |
| 3 | 95 | 109 | 5 | 14 | 623 (Ø10) both ends |
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 bearing pockets | Ø10 | 623 bearing | press | conrod-* |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| Long Earth Society | Tri-clamp Stirling engine builds | web, video | LES site |
| James R. Senft | An Introduction to Stirling Engines (piston fit and leakage) | book | Moriya Press verify |
| ASME | BPE tube dimensions (16 ga sanitary tube) | standard | ASME verify |
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-1.5in-58 | 1.5 in con-rod, 58 mm centres, 5 mm thick, Ø10 623 pockets both ends (wrist pin and crank pin Ø3) | STEP · STL |
| conrod-2in-70 | 2 in con-rod, 70 mm centres, 5 mm thick, Ø10 623 pockets both ends (wrist pin and crank pin Ø3) | STEP · STL |
| conrod-3in-95 | 3 in con-rod, 95 mm centres, 5 mm thick, Ø10 623 pockets both ends (wrist pin and crank pin Ø3) | STEP · STL |
Plain text: sheet.txt · JSON: /api/geometry?object=tri-clamp-con-rod
How it fits
Connects to
Tri-clamp power pistonsmall-end 623 on the Ø3 wrist pin
Tri-clamp crank webbig-end 623 on the Ø3 crank pinAlternatives
Crank discs for a Ø5 shaft, 10 to 30 mm strokeother rod lengthsAlso needed
Ball bearings, 683 to 6210 and flanged F6xxtwo 623 (3 × 10 × 4)You might also need
Questions
How long is the 2 inch tri-clamp con-rod?
70 mm between centres, 84 mm overall, 5 mm thick, with a 623 pocket (Ø10) at each end.
How are the con-rod lengths worked out?
Wrist-pin height + crank height + half the stroke: 23.5 + 34 + 12 ≈ 70 mm for 2 in.