Exhaust cones

[Ch@oZ]

Hello. During building my plasticard jetfighter i stumbled upon a sizeable obstacle- jet exhaust cones. As jet intake tutorials already exist, I've decided to share my method for building jet exhaust cones. The method is rather time-consuming, but the effects are worth it.

1. Acquire 0,25mm plasticard (HIPS, sheet styrene) and a papercraft template of the model you're building. Or scale-up one for Your purposes. Or go to step 3, if You feel You can brave through this without templates.

2. Cut out the chosen cone layout. Cut 2mm down from the thinner to the wider edge. From the tip of the 2mm line cut 1mm to each side, and then back up. For me the cone was 22mm on the wider side and 15 mm on the thinner. The length was 18mm. These measurements are important for further steps.

3. Acquire a program, which can be used to print out cone layouts. "The cone" is one, supposedly, or "Cone layout", which I've used.

4. The backbone of the cone consists of two cone layout layers. Bear in mind, that plasticard thickness has to be taken into account for them- I printed out layouts for 21mm wide, 14mm thin, 18 mm length and a layout for 21,5mm/14,5/18. Cut templates out of plasticard (use watered pvc to glue paper to plastic).

5. Cut two strips of 0,25mm plasticard roughly 1-2mm wide and circa 10mm long.

6. Print out a spare paper exhaust cone of the final size and glue it into shape using gel superglue. This will serve as a drying form.

Here You can see the first layer of flaps' templates and the cone layouts.

7. Glue the smaller plastic layout into a cone shape, using the thin cuts of plasticard as Your suports, by gluing them perpendicular along the seam. I've glued one on the wider edge and had to remove it later. Hold the cone with two fingers along the seam, until the glue is semi-dry.

8. Push the plastic cone into the paper drying form and leave to dry

9. Glue on the medium sized plastic cone layout onto the dried thinner cone. I've placed the new seam roughly opposite the old one, to make the structure more round.

10. Push the two layers You've glued into the drying form and leave to dry.

11. Back to the papercraft cone- cut it into separate flaps, as seen in the first picture. Use watery PVC glue to place this big flaps onto 0,25mm plasticard and cut them out once dry. Wrap the plastic cutouts around a pen or thick marker and secure with rubber bands. Leave this contraption to pre-strain the flaps.

12. Glue the big flaps around the dry 2-cone template, as seen here:

13. Force into the drying form and leave to dry. Run the tip of a knife or edge of a file between the flaps to separate the flaps visaully.

14. Print more papercraft tempates and cut out flap sets, as seen here, and glue onto plasticard. You will need six of each (i lost two, oh well):

15. Wrap all around a pen using rubber bands, like before:

16. Glue the controlling flaps on, starting from the biggest ones. Glue each size sepearately (max six at a time) and force into dryer mold in between size-steps.

17. Once all the layers are glued on this is the result:

18. Cut out the parts of the two inner cones, that can be seen in the tip openings of the first layer of flaps, as in the picture above.

19. Done. Have fun and tell me how it went!