# Build list: Ross yoke alpha, two parallel 10 mL syringes > What parts do I need to build a Ross yoke alpha, two parallel 10 mL syringes? - Category: Stirling engines › Guide - Kind: List / guide - Basis: Every printed part is a free file on this site. - Page: https://xemstudio.com/objects/list-ross-yoke-alpha/ · JSON: https://xemstudio.com/api/geometry?object=list-ross-yoke-alpha · Plain text: https://xemstudio.com/objects/list-ross-yoke-alpha/sheet.txt - License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses **Exact dimensions.** True size, with no printing tolerance added. ## Notes - Two syringes side by side, one crank, a Ross yoke solved for 90° and near-straight piston motion. - Numbers: e 6 · yoke a = h = 20 · link 40 · rods 60 · strokes 17 mm (2.8 mL each) · 90.0° · rod angle < 1° ## Sizes | subsystem | object | parts | qty | note | |---|---|---|---|---| | Frame | ross-yoke-kit | ross-frame-2x-10ml | 1 | print on its back | | Yoke | ross-yoke-kit | ross-yoke-a20-h20 | 1 | a = h = 20: 90° between the pistons | | Rocking link | ross-yoke-kit | rocking-link-40 | 1 | frame post to the yoke's top-middle pin | | Crank disc | ross-yoke-kit | ross-crank-disc-e6 | 1 | e 6, the yoke's bottom corner rides its pin | | Con-rods | ross-yoke-kit | conrod-60 | 2 | yoke corners to the piston forks | | Pistons | syringe-pistons | syringe-piston-10ml-f008 | 2 | lap into the barrels, run dry | | Cylinders | plastic-syringes | syringe-10ml | 2 | barrels only; flanges turned front-to-back | | Crankshaft | stirling-shafts-and-rods | crankshaft-5x80-dflat | 1 | | | Bearings | ball-bearings-metric | bearing-625 | 2 | both ends of the boss | | Pins | stirling-shafts-and-rods | pin-3x20, pin-3x12 | 1 | 2 × 3×20 (crank pin, rocking pin) + 1 × 3×20 (frame post) + 2 × 3×12 (rod pins). | | Spacers | stirling-shafts-and-rods | spacer-5mm-t2, spacer-3mm-t1, spacer-3mm-t5, spacer-3mm-t2 | 1 | 2 on the shaft; 1 between disc / yoke / rods; 5 + 2 under the link | | Pin collars | shaft-collars-clips-and-shafts | collar-3mm | 3 | crank pin, rocking pin, frame pin | | Piston pins | dowel-pins-metric | dowel-3x12 | 2 | through each piston fork | | Flywheel | nut-weighted-flywheels | flywheel-100-m8-b5 | 1 | behind the boss | | Flywheel weights | nut-weighted-flywheels | nut-m8 | 12 | remove until it still carries | | Transfer | alpha-twin-crank-90 | transfer-tee-4mm | 1 | between the tips, mesh plug inside | | Tube | silicone-tube-and-fittings | silicone-tube-4x6-50 | 1 | short | | Mount | t-slot-extrusions | 2020-100 | 1 | foot: 2 × M5 at 50 mm | | Heat | tea-light-candles | tea-light-38x16 | 1 | under the hot barrel's tip end | ## Where the files are - Long Earth Society: [Engine builds](https://longearthsociety.com/engineering/) — web, video — LES site ## Build order 1. Print frame, yoke, link, crank disc, two con-rods, two syringe pistons, shaft, pins, spacers, flywheel, tee. 2. Lap each piston into its barrel; no oil. 3. 625s into the boss; shaft with the 2 mm spacer; crank disc on the D-flat. 4. Press the 3 × 12 pins into the yoke corners and a 3 × 20 into its top-middle; yoke onto the crank pin (1 mm spacer), collar. 5. Con-rods on the corner pins; rocking link on the top-middle pin over 5 + 2 mm spacers and onto the frame-post pin; collars. 6. Pistons onto the rods with 3 × 12 dowels; barrels over them from below, tips up, flanges front-to-back; pinch screws. 7. Tee and mesh between the tips; flywheel behind the boss; heat one tip end; flick. All printed STLs: https://xemstudio.com/objects/list-ross-yoke-alpha/stl-list.txt ## Questions **What parts do I need to build a Ross yoke alpha, two parallel 10 mL syringes?** 23 parts, every one a free STEP/STL on this site; see the table and the build order on this page. **How do I download every STL for this build at once?** The stl-list.txt on this page lists every printed part's STL URL. ## Fits with - [Ross yoke alpha for two parallel 10 mL syringes: frame, yoke, rocking link, crank and con-rods, solved for 90°](https://xemstudio.com/objects/ross-yoke-kit/) - [Syringe pistons: ring-less printed pistons with a con-rod fork for 10, 20 and 30 mL syringe barrels](https://xemstudio.com/objects/syringe-pistons/) - [Plastic syringes 1–60 mL as pistons and cylinders](https://xemstudio.com/objects/plastic-syringes/) - [Stirling shafts and rods: Ø3 rods, Ø5 / Ø8 D-flat crankshafts, Ø5 tube rods, Ø3 pins, thrust spacers](https://xemstudio.com/objects/stirling-shafts-and-rods/) - [Ball bearings, 683 to 6210 and flanged F6xx (ISO 15)](https://xemstudio.com/objects/ball-bearings-metric/) - [Shafts, D-flats, set-screw collars, E-clips (DIN 6799) and circlips (DIN 471)](https://xemstudio.com/objects/shaft-collars-clips-and-shafts/) - [Dowel pins, 2–6 mm (ISO 2338 / DIN 6325)](https://xemstudio.com/objects/dowel-pins-metric/) - [Nut-weighted flywheels: Ø100–200 with hex pockets for M8, M10, M12, 3/8 and 1/2 in nuts](https://xemstudio.com/objects/nut-weighted-flywheels/) - [Alpha V-twin: 90° two-pin crank discs, V block, transfer tee](https://xemstudio.com/objects/alpha-twin-crank-90/) - [Silicone and PU tube, hose barbs and push-fit fittings (the transfer port)](https://xemstudio.com/objects/silicone-tube-and-fittings/) - [Aluminium T-slot extrusion: 2020, 2040, 2060, 2080, V-slot, 3030, 3060, 4040, 4080, 1010, 1515](https://xemstudio.com/objects/t-slot-extrusions/) - [Tea lights, maxi tea lights and votives (heat sources)](https://xemstudio.com/objects/tea-light-candles/)