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Author Topic: how do you make the torpedo fire  (Read 6108 times)

martinbrewster

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how do you make the torpedo fire
« on: June 01, 2011, 08:59:53 PM »

 Italeri S-100 Schnellboot can any body tell me how to make the torpedo fire
thanks martin
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Roadrunner

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Re: how do you make the torpedo fire
« Reply #1 on: June 02, 2011, 01:00:36 AM »

With great difficulty i imagine.

There are methods,.. pyrotechnics could be one method ( but i would'nt try that at home!)  the other maybe a spring loaded torpedo tube, similar set-up to how kids toy guns work when they shoot you in the head with one of those rubber bullets!

This method will work but its a basic guide you will need to play with it to fit your needs. you may want to also consider the retrieval of the torpedoes you fire some how...
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wartsilaone

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Re: how do you make the torpedo fire
« Reply #2 on: June 02, 2011, 01:16:17 AM »

There is a video on youtube where a magnet is used to operate a switch which starts the torpedo motor. The torpedo then just propels its way out of the tube. The switch is on the torpedo and is probably a reed switch. The magnet is on the sub and ether moves past the switch or it could be an electro magnet.

Ali.
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steve pickstock

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Re: how do you make the torpedo fire
« Reply #3 on: June 02, 2011, 07:11:08 AM »

The torpedo then just propels its way out of the tube.

Surely that only works where the torpedo is underwater and there's something for the props to work against? This is above the water.
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wartsilaone

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Re: how do you make the torpedo fire
« Reply #4 on: June 02, 2011, 09:18:43 AM »

Pardon my ignorance, I assumed it was a sub. You learn something every day.

Ali.
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Roadrunner

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Re: how do you make the torpedo fire
« Reply #5 on: June 02, 2011, 11:40:34 AM »

If it was a torpedo from a sub  then your method would work just by powering the torpedo out of the tube, but in this case its a 'fast launch' which the torpedo is thrown from the deck, which means my method would do the job of launching it of the deck, powering the torp up I'm leaving to the builder to figure out, (bit of self help goes a long way) although i can't really see a point in making the torpedo's work, you will most likely loose most you fire, which is a costly feature, unless its being used for display purposes it becomes a redundant feature.
There are to many things to consider on a torpedo, planes to help it plane right in or above the water, and if there fixed then you have issues at scale with a poor launch can result in just making a splash and the item hitting the lake bed with some force, which is not the effect you were going with, that's just one of the list of things that you have to over come.

Trial and error through bench testing it best before fitting to the model. I have my doubts if you can achieve working launchers but i would like to be proven wrong, so crack on boy!
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hopeitfloats

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Re: how do you make the torpedo fire
« Reply #6 on: June 02, 2011, 11:48:53 AM »

it would certainly need a strong spring to launch and propel any distance. have you got deep pockets for this project because i i think you will need them.  a compressed air system would be one way around it but as said earlier, recovering torpedo's will be a problem however you do it. good luck though and photo's/video if it works please. :-))
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Roadrunner

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Re: how do you make the torpedo fire
« Reply #8 on: June 02, 2011, 12:02:10 PM »

I have my doubts as it is, since the question on how to fire one was asked! So I've suggested an 'idiot proof' method that won't kill you should it go wrong! compressed air from a source, (fire extinguisher, or small compressor) would work nicely.. but umm like i said i have my doubts.

You will be surprised how strong a 'small spring' is and the distance they can fire, go down to your 99p shop and buy a toy gun and shoot the bullet, you get about 6 foot distance in flight on most ( some more if you spend more cash) 6 foot with a cheap toys spring is enough to launch a light weight 'torpedo'  of the deck i would have thought,, some suggestion on springs would be use some from a Tranxx Rc Truck (i have loads spare)  those springs hold the weight of a 4kg monster truck & engine up and take the compression of the suspension (under my rough punishment) ... ( although 4 per wheel) but one is enough to launch a Nail across my workshop all 16 foot of it with good effect, trust me i tried it in boredom once!!
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wartsilaone

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Re: how do you make the torpedo fire
« Reply #9 on: June 02, 2011, 12:05:53 PM »

I think the inner workings of a toy gun would do nicely. you could use the ends of the dart things to lock the torp in.
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Roadrunner

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Re: how do you make the torpedo fire
« Reply #10 on: June 02, 2011, 12:11:38 PM »

I will try to get to the workshop later today or tomorrow and make up a torp tube with  firing pin and get a vid of it working at a basic level with a spring from my tranxx truck, just to proive the method works, i will most liklt fire a nail as the head makes a great 'notch' and had a nice flat head for the spring to be in contact with  :-)) besides im i need to shoot something  %%
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philk

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Re: how do you make the torpedo fire
« Reply #11 on: June 02, 2011, 12:25:25 PM »

you will also need to bear in mind the kit in question is 1/35 scale that means the torpedo's will only be 15mm in diameter

phil
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hopeitfloats

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Re: how do you make the torpedo fire
« Reply #12 on: June 02, 2011, 12:27:26 PM »

does the torpedo have to run in the water or just launch off the ship. a spring would launch ok but i think it would need a seperate system to propel it through water as well. what size torpedo would it be (diameter, length etc).
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hopeitfloats

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Re: how do you make the torpedo fire
« Reply #13 on: June 02, 2011, 12:29:01 PM »

whoops. half the question answered. %)
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Roadrunner

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Re: how do you make the torpedo fire
« Reply #14 on: June 02, 2011, 12:38:14 PM »

you will also need to bear in mind the kit in question is 1/35 scale that means the torpedo's will only be 15mm in diameter

No guarantees... you just assumed that.. he could be making a larger scale model from plans or a hull with the rest scratch built... were not told what scale or if its a kit, you are right that the plastic kit is 1:35th but still we don't know, however....

If it was me.... i would use a tiny prop ... a single  AAA battery and wire it to a motor from a servo to just spin up you can fit that (just) in a 15mm torpedo!

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hopeitfloats

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Re: how do you make the torpedo fire
« Reply #15 on: June 02, 2011, 12:59:57 PM »

my idea was a bit more elaborate. :embarrassed: spring loaded to launch off the ship and a magnet in the deck to trip a reed switch as the torpedo passes over it and starts the electric motor. feasible or not. what do you think. the only problem i could see would be positioning the magnet. it would take time to make but i dont think it would be that expensive to do.
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steve pickstock

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Re: how do you make the torpedo fire
« Reply #16 on: June 02, 2011, 01:20:12 PM »

I think if you just want to eject the torp from the tube a spigot system into the base of the weapon and powered by a sparklet's system would do it.
You can screw the sparklet bulb into place in the hul, which would charge the system. Have a Safe/Armed valve in line, and once it's all ready open a rotating valve to launch the fish. Just got to remeber to close the launch valve afterwards or there won't be anything left in the system to power a second launch.
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unbuiltnautilus

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Re: how do you make the torpedo fire
« Reply #17 on: June 02, 2011, 03:32:56 PM »

We have a system for launching torpedoes from a 1/24 scale 71' Vosper boat being developed down here in Portsmouth. We decided to go with expendable torpedoes, so no motors etc, the firing was the effect. This uses an air cannister from an Air Retract System for model aircraft undercarriages, this is charged to between 40 and 60 psi and the full charge is dumped into two 1/8" dia lengths of K&S brass tube fixed inside the torpedo launcher. The torpedo has a long hole drilled into it and the next size up K&S tube is bonded into it (5/32"?). The air venting into this long pair of tubes is enough to propel the torpedo ( an 18mm plus diameter piece of hardwood dowel ) across the floor over 6' from lthe launch model. The dowel torpedoes can be recovered from the pond afterwards as they drift downwind to join the other debris!
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steve pickstock

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Re: how do you make the torpedo fire
« Reply #18 on: June 02, 2011, 03:48:34 PM »

That is what I was describing - the smaller of the tubes is the spigot - provides guidance and support during the launch. Substitute the sparklets bulb for your aircraft cylinder and Bob is you mother's brother.
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unbuiltnautilus

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Re: how do you make the torpedo fire
« Reply #19 on: June 02, 2011, 04:02:27 PM »

Indeed you are correct, however Bob was my fathers brother, however I will let that pass :-))
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Listen politely, nod approvingly, then do what you want, works for me!

steve pickstock

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Re: how do you make the torpedo fire
« Reply #20 on: June 02, 2011, 07:26:43 PM »

My rofund propologies.
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philk

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Re: how do you make the torpedo fire
« Reply #21 on: June 02, 2011, 11:30:37 PM »

No guarantees... you just assumed that.. he could be making a larger scale model from plans or a hull with the rest scratch built... were not told what scale or if its a kit, you are right that the plastic kit is 1:35th but still we don't know, however....

If it was me.... i would use a tiny prop ... a single  AAA battery and wire it to a motor from a servo to just spin up you can fit that (just) in a 15mm torpedo!



not unless italeri make two kits which they don't
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Roadrunner

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Re: how do you make the torpedo fire
« Reply #22 on: June 02, 2011, 11:32:29 PM »

lol doh!  {-)
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NickKK

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Re: how do you make the torpedo fire
« Reply #23 on: September 30, 2011, 03:25:30 AM »

I'm just starting to play around with torpedo's .... I have tested a torp out with a reed switch motor and battery. The magnet should be on the torpedo tube. I was thining of loading the torp under spring preassure and using a slot cut in to the deck for a longer extended servo arm .... flick the switch, servo arm moves out of the way ... sprinf pushes torp out of the tube and once the reed switch is clear of the magnet the motor starts ... I have seen in the USA a torp launching system used on submarines built by Caswell ...1/72 scale using vibration motors I think .. Another system used contra rotating shafts and a scalectric car diff  one shaft running inside the other ... not sure how big that would make it ...
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hopeitfloats

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Re: how do you make the torpedo fire
« Reply #24 on: December 15, 2011, 10:37:45 AM »

nick...did you get your torpedo system to work
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