$20.00Propfan Engine, Pusher Type

myminifactory

Propfan Engine, Open Rotor Engine, and Ultra High Bypass Engine were developed as Advanced Turboprop Engine to achieve high flying speeds while consuming about the same amount of fuel as a Turboprop Engine. Several types of engines exist, including Puller (Retract) type and Pusher (Un-Ducted Fan) type, with different configurations. The development of these engine types seems to have been halted due to noise issues, except for one company in France. I was particularly interested in the contra-rotating power turbine mechanism with sweep-back angle fan blades of the Pusher Type. I attempted to create a desktop model but encountered difficulties achieving smooth contra-rotation. After several trial and error attempts, I successfully created my target model. The features of this model include: 1) Contra-Rotating Fan (PT: Power Turbine) can be turned by a home type vacuum cleaner; 2) Engine (Gas-Generator) cutaway model is inside the cowling but not rotated by air; and 3) Entire engine cowling with removable cover. Video: https://youtu.be/2Hu1QvJ5J9o B. Assembly Manual (PDF format, total 19 pages) The assembly manual includes detailed instructions for "Parts-List," "After printing treatment," and "Assembly procedure" based on Standard Skill (Filing, Drilling, Tapping, and painting). The important adjustment of axial clearance is described in the manual as marked ●. C. General Notes 1. Bearing Selection: Bearings are crucial components to achieve smooth rotation. This model uses Open type ball bearings with low friction due to the following sizes: ID x OD x W = ① 7 x13 x 3, ② 9x17x4, and ③ 17x30x7 (2pcs). [CAUTION]: Shield type ball bearing is thicker, which may cause rubbing issues. 2. For M1.4 Screw: No need to "Tapping." Drill with φ1.0 drill then directly screw-in. 3. STL file name "ws" of last 2 digits means With Support special designed. Download files include: * STL Files (48 items) * PDF(Zip) File: Assembly Manual * images: Assembly Photos Purchase Parts Information: * BRGs - See Assembly Manual * Aluminum Tubes - See Assembly Manual * Screws Micro screws M1.4x3.5L - Approx. 30 ea - Direct screw-in to 1 mm dia hole (No nut) * Screws M2 x ** - See Assembly Manual Assembly Points: * Standard Skill (such as Drilling, Tapping, Filing, Tightening, Painting and Gluing etc) is needed and perseverance too. * Others: See Assembly Manual Total Net Print Time: Approx. 80HR - (Estimated as case of PLA, 0.4mm Nozzle, 0.2mm Layer Height, 40% infill and No raft and support) Note: When at actual print, each parameter may be adjusted by your experience.