Lakeroadster's Top Secret 2.0

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

lakeroadster

When in doubt... build hell-for-stout!
Joined
Mar 3, 2018
Messages
9,922
Reaction score
12,977
Location
Central Colorado
An upscaled re-design of Bret Simpkins "Top Secret" model rocket, circa 1973.

This upscale features a Pine Nose Cone, BT/C-55 Body, 1/8" Basswood Fins and Oval Tube Fins. Powered by 24mm or 29mm motors.

This rocket will be a test mule for a "new to me" rear eject that spits the motor out the back, and drags the parachute out with it. It has a motor tube to redirect all the ejection debris out with the rocket... the chute will never see the ejection charge.​
The motor slips fits into the motor tube and is temporarily secured with a small piece of masking tape.​
A D12 lifts the rocket to about 700' apogee... we'll try it on this motor for it's maiden voyage.​

2025-10-18 Top Secret 2.0 - Open Rocket Simulation - 3D Finished.jpg2025-10-18 Top Secret 2.0 - Open Rocket And Spool Side View.jpg2025-10-18 Top Secret 2.0 - Open Rocket Simulation - Photo Studio.jpg2025-01-18 Top Secret 2.0 Pictorial Drawing.jpg
 
Last edited:
I took some time to create an actual model in Open Rocket of a Aerotech G74 Motor for this rocket. It can be inserted into the model as a Pod, using the Override tab to zero out all the values..

Why?

The design of the motor isn't accurately reflected by using the standard motor in Open Rocket. The ejection nozzle sticks out farther, and the thrust nozzle does also.

On this rocket, the ejection nozzle is in a space restricted motor tube. Not a big deal, but I have the tools available to accurately reflect the design.

2025-01-19 Top Secret 2.0 With F42T Motor and Standard Open Rocket Simulation Top View - 1.jpg2025-01-19 Top Secret 2.0 With F42T Motor Open Rocket Simulation Top View - 1.jpgG74 Open Rocket -1.jpg
 
Last edited:
Now... you might say, come on Lake, they are close enough.

Let's look at an E20 motor... the actual ejection nozzle is huge in comparison to the Open Rocket motor...

2025-01-19 Top Secret 2.0 With E20 Motor and Standard Open Rocket Simulation Top View.jpg2025-01-19 Top Secret 2.0 With E20 Motor Open Rocket Simulation Top View.jpgE20 Open Rocket - 1.jpgE20 Motor.jpg
 
Last edited:
This rocket will be a test mule for a "new to me" rear eject that spits the motor out the back, and drags the parachute out with it. It has a motor tube to redirect all the ejection debris out with the rocket... the chute will never see the ejection charge.​

Wouldn’t that make it a “Bottom Secret?”
 

Latest posts

Back
Top