This is the Variable Nozzle for Jet Engine Afterburner (Reheater, Augmentor).
There are several type of Variable Nozzle. This is the Cam & Roller Type by my imagination.
This model was designed in order to understand what the elements are required to Variable Nozzle mechanism.
A. Design points (Cam & Roller Type):
1. Cutaway model to see Mechanism and Nozzle Movement.
2. Open /Close of Nozzle can be done by the tool.
3. Ball Joint is used one end of Link rod only, because too small to print.
4. This can be disassembled and assembled by the screw drivers.
Related this, Flap total quantity is limited to ten (10). Seven (7) flaps are used for this cutaway.
5. Open / Close diameter ratio is about 1.35 (=1.8 area ratio).
[Next Model] "Link Rod Type" Nozzle will be made. - See photo shown Types.
B. Assembly Manual (PDF format, total 22 pages)
The detail assembly manual including "Parts-List", "After printing treatment" and "Assembly procedure" are prepared based on "Standard Skill (Filing, Drilling, Tapping and painting)".
My design hole diameter is considerably smaller than the finish hole diameter in order to ensure the wall thickness at the time of printing.
Then the following drills and Tap required.
Drill : φ1, 1.5, 2, 2.5, 3.5, 5.2 Tap : M1.4 (Optional), M2, M3.
For the parts having small ball end, carefully drill to finish hole, then carefully break ball stickiness.
If ball comes out part, use suitable size washer and your printed plate at assembly.
C. Download files includes;
- files: STL Files (29 items)
- “ws” of last 2 digits means “With Support” special designed.
- PDF(Zip) File: Assembly Manual
D. Purchase Parts Information; - See Assembly Manual
- Aluminum Tubes - φ3
- ABS Pipe - φ5
Micro screws M1.4x3.5L and 6L - Direct screw-in to 1 mm dia hole (No nut)
But there are many small parts, if you can get M1.4-P0.3 Tap, using it to make introducing thread is recommended.
Quantity of screws can be adjusted by your experience.
Screws M2 x *, M3 x *
E. Total Net Print Time: Approx. 60HR
- (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.
Retired Aircraft Engine Engineer