Mid-Winter Blues

[TuptubBuilder]

DISCLAIMER: Chemically propelled projectiles are inherently dangerous. The following is for educational and or entertainment purposes, any attempt to replicate it is done so at your own risk.
This project is a “proof of concept” for a torpedo launch system. It is not configured to fit in any scale boat. I just want to see if it warrants further development.
The concept:

1. Deposit a metered amount of baking soda (sodium bicarbonate) into the torpedo.
2. Load and lock the torpedo into the launch tube.
3. Inject a metered amount of cleaning vinegar (acetic acid) via peristaltic pump.
4. Let the reaction “cook” for a few seconds and then release the launch lock.

The reaction byproducts are: water, CO2 and sodium acetate.
The water adds some mass to the propellant and it should behave like a horizontal bottle rocket.
The test device was completed in late September 2025 but then, life got in the way and testing never happened. I have hand launched the torpedo (it’s messy) and it looks promising.
Know Pros: cheap and simple to make and operate, and it’s reusable (number of times TBD).
Known Cons: aside from the potential danger as a KE device, the torpedo becomes a pressure vessel subject to catastrophic failure (think bomb). I haven’t addressed the case for misfires yet.
I hope to post test results in the Spring if it ever thaws out here in the North.

[redboat219]

Had the same idea 20 years ago. Tried it with a pen full of baking soda. Squirted some vinegar using a syringe. My reaction produced little gas. Either the amount of reactants were insufficient or expired.

How about using hydrogen peroxide.

[redboat219]

Might be illegal in your place

https://youtube.com/shorts/EN_tFMjLh40?si=c7KqOoAYWEKAeXlu

[TuptubBuilder]

Had the same idea 20 years ago. Tried it with a pen full of baking soda. Squirted some vinegar using a syringe. My reaction produced little gas. Either the amount of reactants were insufficient or expired.

How about using hydrogen peroxide.

My first attempt was to slip fit the brass tube nozzle to an O Ring and let the pressure launch the torpedo. This arrangement did not allow enough pressure to build up. Locking the torpedo in the tube and allowing the pressure to sufficiently build solved that problem.

[RCSubGuy]

I'd love to see how this prooves out. The trail of soda and bubbles should be pretty cool, too!

[TuptubBuilder]

I probably should have posted this version first. This first attempt was without the launch lock and check valve. I also had to fix all the torpedo leaks. An O-Ring replaced tape, JB Weld replaced CA glue and threads replaced a press fit.

[TuptubBuilder]

Better image

[redboat219]

...........

[He Who Shall Not Be Named]

...........

Ouch!

(she asks: "Who you gonna please with that little limp thing?" I answer: "Me!")

[TuptubBuilder]

Even better image

[Albacore 569]

Funny and timely. Drachinfel just posted a video article on 19th century early torpedo inventors.

'Experimental Torpedoes of the 19th Century - The Roads Not Taken' Just posted yesterday. Yes attempts with Vinegar and baking soda too. lol

I have a question; I think electric torpedoes have been well demonstrated. But could automatic pitch control electronics be miniaturized further and used in model torpedoes too? Not only for pitch but azimuth too? I don't see why not. Make miniaturized device and combine pitch but azimuth into one tiny unit? Tiny control rods to the tail surfaces or a tiny gyroscope forward to elevate the need to tail surfaces? Just thinking out loud.

[redboat219]

Maybe make one in 1/35

[TuptubBuilder]

Funny and timely. Drachinfel just posted a video article on 19th century early torpedo inventors.

'Experimental Torpedoes of the 19th Century - The Roads Not Taken' Just posted yesterday. Yes attempts with Vinegar and baking soda too. lol

I have a question; I think electric torpedoes have been well demonstrated. But could automatic pitch control electronics be miniaturized further and used in model torpedoes too? Not only for pitch but azimuth too? I don't see why not. Make miniaturized device and combine pitch but azimuth into one tiny unit? Tiny control rods to the tail surfaces or a tiny gyroscope forward to elevate the need to tail surfaces? Just thinking out loud.

I looked for an "al in one" flight controller for a micro quadcopter to fit the bill. It has stability control and ESC built in. The only problem is the form factor (cross shaped).

[redboat219]

could automatic pitch control electronics be miniaturized further and used in model torpedoes too? Not only for pitch but azimuth too? I don't see why not. Make miniaturized device and combine pitch but azimuth into one tiny unit? Tiny control rods to the tail surfaces or a tiny gyroscope forward to elevate the need to tail surfaces? Just thinking out loud.

Maybe use one of those RC heli heading lock gyros to make it run straight.

Here's a 1/12 rc torpedo from Japan
540mm length, 40mm diameter

Corona receiver
550 lipo battery
2 FA 130 motors
PICO X2 Servos
MS10 ESC
PS10 automatic pitch controller