Another torpedo thread?

[cstranc]

I was out shopping, just

I was out shopping, just to see what I could see...



So I found some relatively small O-rings. This was at a hobby store that really specializes in RC cars & trucks. The O-Rings are made by HPI-Racing. You can see they fit snugly on a 1/8" rod.

Also I have some 1/16" aluminum tubing (inside diameter 0.014") (on the far left) I was wondering if this would be good for the gas pickup tube? I could use a few short lengths of brass to get the diameter up to 1/8" so the O-ring would seal on it. Or possibly just push O-ring on to the tapered end of the torpedo.

The two tubes on the right are potential candidates for the body of the torpedo. The tent peg, while it is stylish, is a little too small for the 1/60 scale. The aluminum tube to the far right is closer to correct.

Why would I choose to make my torpedoes a little small?



I will be doing the retractable dive planes thing also, and you can see things are going to get a little crowded up front. I bet the force of good modelling will win out and I will switch to the correctly sized tube, but it will mean that I will be forced to build and install the dive planes at the same time. Not something I would want to retrofit later.

The top half of this hull is removable. That means that the front section of the torpedoe tubes will be mounted on the removable top hull. I am assuming that I will actually attach the working part of the torpedo launcher and dive planes will be mounted to the lower hull.

Alignment could be an issue between the top and bottom hulls...

Has anyone tried to have the working part of the torpedo assembly seperate from the actual tubes on the hull. Brrr. It sounds like a potential weakness.

[pirate]

Is that a shkvall torpedo

Is that a shkvall torpedo you got goin' there, Kevin?

Pete

[ramius-ii]

another question

Aside from the other questions about two posts ago, the small inside diameter aluminum tube is .0345 as the inside diameter! Where would you get 1/16 tubing that is .014 I.D.?

Ed

P.S. I hope someone will help with the other question. Thanks

[cstranc]

The tubing I picked up

The tubing I picked up at the hobby store. It's the normal K&S engineering stuff. The label reads:
1/16 x .014
RD. ALUM
Stock # 1008

When I measure it the OD is 0.062"
And the wall thickness is about: 0.020"
So really the ID would be about 0.020".

Sorry for leading you astray.

Chris

[ramius-ii]

Not A Problem

Hi Chris,
No problem, we are both working on the same project.

For some unknown reason suppliers here in Los Angeles lean towards cars and airplanes and finding sutible materials can be difficult. It is much like hurry up and wait for deliveries.

For me, it was more of a confusion and slight concern that if the ID was large and you insert the hypo tube into the aluminium tube it would not be straight. It is very impressive to see your designs and workmanship.

How on earth do you achieve the groove for the 4 each 90 degree fins at a 15 degree angle for spin?

From your pictures, the amount of material to be inserted into the aluminum tube seems a bit much. Is there a reason for this? Like balance?

Thanks for you time and insights.

Ed

[Wheelerdealer]

I have been playing around

I have been playing around with torps too. I use an internal fil valve like the Mike Dorry design. Like Kevin I am going for alluminium tube body with polyurethane ends. The nose cone pulls out to reveal the fill valve . I use an insulin syringe needle as the gas pick up glued inside a 1/16" brass tube which becomes the knozzle. An oring on a bass cap (machined like a subtech BHS seal but with one end sealed) is used to plug the knozzle. By using a lighter refill valve I can get down to 1/72 without any trouble for a 533mm torp or about 1/90 if your calling it a 650mm torp). The torp is filled outside the sub and then inserted through the external tubes and locked in place via the blocking brass caps. The torp is fired via a servo which pushes the torp off the cap. I actually have a preferance for using lighter refill. The valve is smaller and lighter, it seems to be stored under less pressure, so the torps travel slower and more scale like and travel straighter. Not powerfull enough for the torp to fly through the air (and poke someone in the eye) and you can hold the torp quite safely with two fingers when the gas is released and torp is running. Sure its flamable, but no more dangerous that the lighter in your pocket.

Here a link i've come across.

http://translate.google.com/translate?u ... uage_tools

[cstranc]

It's a pity that electric

It's a pity that electric version was too heavy. It looks amazing.

Thank you for the instructions on the gas propelled. I will make a nice cup of coffee and sit down for a good read.

Chris

[subshop]

torpedoe

chris, i too have been toying w/ electric torpedoes and weight has definitely been an obstacle to overcome . i have been using casting materials and have been able to reduce the overall weight by 1/3. but i still need to shed more weight. the gear section along with the gears themselves have proven to be a challenge.
i have since moved on to a different part of my build so as not to trash the whole idea of the electric "fish". if you would like to see my progress go to
http://s181686668.onlinehome.us/phpB...ageboards.php5.

neil

[cstranc]

Neil,
I would love to

Neil,
I would love to read up on that. The link you posted seems to get me back to the forum. Not a specific topic.

I find that when you right click on a topic and "open in new window" that URL works better in posts.

Look forward to reading up on your work. And I am amazed you could find gears that could fit in a torpedo!

Chris

[subshop]

TORPEDOES

CHRIS, SORRY, GO TO THE FLEETBOAT DOCK FORUM. Then look for the thread "1/32 scale torpedoes and casting materials. The gears i used are brass 1/8 " bore miter gears . To fit three of them into the gear section of the torpedoe , i first soldered them to a 1/8" brass shaft then milled down the base by about 3/16". since the planetary is part of the torpedoe's body the more material i can remove the lighter the overall weight will be. The o.d. of the torpedoe is 21/32". The gear and tail section along w/ he nose were all milled from brass rod. the body is just ks tubing. if you read the thread i have been able to cast the nose and tail section from a lighter material. I also used the same casting material to make the gear section. i used plastic gears and have not had much luck. with the brass gears if they did not mesh perfectly i just put the gear box on my lathe and run them down till they wear in and turn real smooth . the gear box i cast with the plastic gears is not so forgiving. the nylon gears will not wear in and tend to cause the gear section made out of the casting material to crack. my next attempt will be to use different combinations: nylon gears w/ brass gear box or brass gears w/ cast gear box. but for now i'm puttting this part of the build on the back burner ! i find if i walk away from a problem and think about it awhile i'll come back with a different solution. neil

http://s181686668.onlinehome.us/phpBB2/viewtopic.php5?t=5599

[KevinMC]

Is that a shkvall torpedo

Is that a shkvall torpedo you got goin' there, Kevin?

Naw... Thought about it, but I've decided to reserve the rocket motors for just the Granit cruise missiles. My fish are just run-of-the-mill Type-53s.

[ramius-ii]

Hey Kevin

Hey Kevin,
Any chance you could post a picture of your torpedo with a ruler in the picture?

Thnaks, Ed

[KevinMC]

Will do Ed.

Will do Ed.

[scott t]

To reduce weight has any

To reduce weight has any one tried flow(spin) forming the nose & tail cones from thin aluminum, such as a soda can?

I remeber getting a aluminum tube that a cigar was sold in, I played with it as a missle when I was a kid. It was not as thin as soda pop can aluminum, but I'm sure they must have spun it into the shape. It included
roundish wide threads for the cap to screw on.

I'm guessing it could be formed over a wood mandrel.

Scott

[KevinMC]

Chris- I also had to

Chris- I also had to deal with the WTC being mounted in the lower half of the hull, but having bow planes and torpedo controls best placed in the upper half of the hull. My solution was to make a secondary WTC. I've placed the bow plane pitch and retract servos in this WTC and I'm currently working on getting the mechanics to drive masts and control electronics for the torpedos into there as well.

As for getting Rx signals to this Aux WTC, I made up an electronic circuit which links the Aux WTC to the Main WTC through a serial IR link. I made a transmitter board plugs into my Rx and transmits the signals for 3 channels out the clear sidewall of the WTC via and IR LED. (Meaning I can pump out 3 channels without drilling any new holes in my WTC.) This signal is received by an IR Rx device mounted to the upper hull half just outside the main WTC. I then built a "decoder board" for this device which I've installed in the aux WTC to send the appropriate signal to each servo. Why'd I go to all this trouble? I can now have servos in each hull half, but when I open it up there are no connectors to disconnect.