Operational Torpedoes in 1/32 scale - Eureka!

[bob the builder]

Well, after much pulling out of hair, grinding of teeth and numerous colorful dialogues between myself and the contents of my workbench, I am very happy to say that I've successfully built and tested a trio of 32nd scale torpedoes for my Type VII project.

https://www.youtube.com/watch?v=riCyu9mAwcs

The bodies were 3D printed. Electronic timers were sourced with a 6 second on state. Trigger is a NO reed switch. Power comes from a 1s LiPo.

During testing, the weapons ran straight and true despite no counter active fins to offset the propeller torque. Speed is just about right in my opinion and the video above shows slightly slower footage underwater and normal time on the surface so you can see for yourself. Battery life is really exceptional and I'm guessing you could do a day at the pond without need for recharge (after all, you're only doing 6 seconds of run time per launch!).

Loading should be able to be accomplished with the boat still buttoned up and likely even still in the water if I am guessing correctly, making for the possibility of a lot of successive launches in a very short period of time.

The R/C boat has twin forward tubes and one aft. She'll be armed for bear!

I should have a final video of the finished boat with weapons operational very soon.

For now, enjoy!

[salmon]

Are you willing to share the source for the timer?

[corsaire]

Short of actually having a real miniature bomb fuse in it it is magnifique!

[thor]

Very nicely done, Bob!

[bigdave]

Yea!
What he said.
Very nice.
Will you have them ejected from the tubes or just have the propeller push them out.
You had mentioned a ejector for the rubber band ones. BD

[jure george]

Hello Bob

First, Thank You for your torpedo post, very inspirational !

I second the request for the timer source and the motor specs/source, please.

Now a basic question, how do you make the tail fins so that they are attached to the tail cone at 90 deg. to each other ???

Thanks again for sharing this.

George

[JWLaRue]

What I got from Bob's video is that the tail cone, including the fins, was 3D printed. Same with the main body.

-Jeff

[Chuck]

Bob the Builder indeed.....actually it should be Bob the Wizard. For years, from your early Nautilus models, you have been an inspiration to the rest of us. Thanks for sharing your superb work.

[corsaire]

Masterful work indeed and I can attest to that. We need to see a "torpedo los!" in action though, hopefully soon.

[bob the builder]

Hoping for video of the torps firing from the boat later this week. I'm shooting for filming Thursday and maybe getting footage up Friday?

Timers can be obtained from curioustech.net. Greg is absolutely awesome to work with and can adjust timing to your liking with your order.

The body of the torpedo was 3D printed in two parts, the front and the tail. I drafted the parts and got them printed at Shapeways. I'll just print on my own Makerbot next time, but it was down when I was working on the torpedoes and I couldn't stand to have to wait.

Stay tuned!

[salmon]

Bob,
Thank you for the information on the timer!
In your video there seemed to be a lot of buoyancy on those torpedoes. Once fired, will the sub all of a sudden be nose heavy? or do you add more weight to the torpedo to make it slightly positive? I am really looking forward to your adventures an thank you for sharing them.
Peace,
Tom

[bob the builder]

I think the perception of buoyancy is a bit of an illusion. The torps are just slightly positively buoyant. On a 30lb sub they won't make a massive amount of difference. The reason they look like they're sitting so high when running is that the tail is heavier than the front (electric motor is much heavier than the battery). With that being the case, the tail sits low and the thrust pushes the weapon up out of the water at the bow.

[jure george]

Hello

If I remember correctly, you said the nose and tail stock were printed through shapeways? If so, are you selling them through shapeways and can you provide a link to them and the piece that holds the motor? Also where did you get the motor and battery from?

Thanks
George

[salmon]

I think the perception of buoyancy is a bit of an illusion. The torps are just slightly positively buoyant. On a 30lb sub they won't make a massive amount of difference. The reason they look like they're sitting so high when running is that the tail is heavier than the front (electric motor is much heavier than the battery). With that being the case, the tail sits low and the thrust pushes the weapon up out of the water at the bow.

Thank you Bob! That makes sense.

[bob the builder]

Hello

If I remember correctly, you said the nose and tail stock were printed through shapeways? If so, are you selling them through shapeways and can you provide a link to them and the piece that holds the motor? Also where did you get the motor and battery from?

Thanks
George

George, the 3d printed parts from Shapeways were quite pricey. I think they ended up at about $20/weapon. I can try and run a set off on my own printer and see how the quality and timing looks. Might be that I could do better than that. The interior motor and reed switch bulkheads were all printed at home quite quickly.

Let me play a bit this weekend and I'll let you know what I come up with. I'll also see if I can source more motors (the bulkheads are set up for these ones specifically).