Wednesday, March 26, 2025

 

Miles M.39C Libellula... A WWII Odd-Roc

 Here's a rather obscure British WWII plane that seems to work nicely as a rocket pretty much as is.

Miles M.39B Libellula Wikipedia

The Miles M.39B Libellula (from Libellulidae, a taxonomic family of dragonflies) was a Second World War tandem wing experimental aircraft built by Miles Aircraft, designed to give the pilot the best view possible for landing on aircraft carriers. A scale version of the M.39 design was proposed by Miles to meet Air Ministry specification B.11/41 for a fast bomber. The M.39B was used by Miles to generate data from which the M.39 design was improved, but the M.39 project was cancelled and the M.39B broken up.
The M.39C was a pusher version... and that's similar to the rocket I've created below.

I moved the motor nacelles in tight to the rear tailcone. The ejection will be through the side wall of the motor tube into the fuselage, and the parachute will eject via bomb bay doors on the bottom of the rocket. At least that's the plan.

I wanted to use some 29mm Estes black powder motors but the off the rod speed is less than 30 mph. Using composite 29mm motors only (1) is req'd... so I can cluster the two motors without fear of one not lighting.

Looks like a fun project. I may opt to not use the front canards.... but I had good luck with my Hammerhead.
 

 



 

 

A couple of videos...

 

Thursday, March 20, 2025

(BAR-44) Gee Bee Pod Racer

I saw the rendering below on the Facebook Dieselpunk Gallery.

It's kind of a bash of Star Wars pod racers, and what I believe to be a 1930's Gee Bee Model R Super Sportster air racer. Gee Bee's were purpose built, just for racing. A way cool airplane that doesn't look like it should even fly.. but fly they did. In 1932 it not only won the Thompson Trophy Race, but actually lapped all the other competitors, except one.

Here's the final design I'll enter into CAD.
  • Standard Front Eject
  • Flies on a single 29mm Motor
  • Using a piece of 3" Steel Pipe as Ballast, buried inside the nose.
  • 30" Dia Nylon Chute
  • Onboard Altimeter Stowage
  • 4" Dia. Nom. Body




 2025-03-21
I was able to finish the CAD Model and create an outline drawing of the BT-400 version. Pretty pleased with the results. 




 
 
2025-03-21 Drawing Set, Sheets 1 through 10, Rev 00
 










 2025-03-23
Somewhere in this mass of wood hides the Engine Cowling / Nose Cone of a Gee Bee Pod Racer.

A 6" piece of 4x4 and (4) 1x4's.... all glued together to be turned on my wood lathe.
 


 
2025-03-24 Prepped the wooden block for turning using my table saw.
 

2025-03-25 Nose Cone ended up turning out quite nice.
 










 2025-03-27 Cutting, Routing, Gluing and Sanding the Fins
 



2025-03-28 Centering Rings and Body Tubes

I made the Centering Rings from 1/4" plywood using a Fly Cutter, a Forstner Bit and my Wood Lathe. Then started wood gluing the Front Centering Ring to the Nose Cone, and the BT/C-80H to the Nose Cone / Front Centering Ring.​
Also located my stash of now vintage B-B's, which I'll be using for Ballast instead of the 3" Sch 40 Pipe.
 





2025-03-29 Nose Cone Ballast

I used 16 Ounces of "Copper Head" (good name for a rocket) B-B's. Placed a 3rd of them, drizzled some wood glue on them, and repeated that 2 more times. I then placed a centering ring over the B-B's and glued it into place.​
Weight of the copper plated steel B-B's is approximately 2.24 Ounces per Cu-In.
 




2025-03-30 
Rear Fins CWF, Slotting the C-55 and beginning to installing Fins
 





2025-04-01 Intermediate Fin Initial Gluing and Slotting the BT-400

The Intermediate Fins glue to the surface of the C-55 and to the Rear Fins.​
Slotted the BT-400 for the Pods.
 






 
Glued the Nose Cone to the BT-400 and applying glue fillets to the Intermediate Fins. Also added some cheaters to the TTW portion of the pod fins.
 




 
2024-04-02 Gluing the TTW Pod Fins to the BT-400

I dry fitted the internal Centering Ring to the BT-80H and it's a tight fit. So I decided to leave it there temporarily and glue the Pod Fins to the BT-400. That should help to keep the BT-400 in place once the glue dries. I can then glue the pods to the BT-80H.​
The rectangular box in the 3rd photo was made from some scrap BT/C-60 from the fin tubes on my Fleet Interceptor. It will glue inside the BT-400 and act as a stowage compartment for my Altimeter Two.​
 



Glue Fillets: BT-400 to Pod Fins
 

 

Gluing the TTW Pod Fins to the BT-80H

Laying down a couple wood glue fillets, then placing the Centering Ring back on.​