Model Gunnery

[Guest]

From time to time I see posts in the model boat sites I visit enquiring about "how to make guns work", and, in particular, how to mimic the smoke/gunflash of large calibre (turreted) guns.

It has been suggested that the model tank technology may provide an answer, hence this post in "General".

Can anyone give advice? The ideal arrangement would need to be small, low cost, realistic, in terms of smoke, flash and sound, bearing in mind that the guns normally considered will be 9.2in (monitors) at the small end and 15inch (battleships) at the large end, and environmentally sympahetic, ie not cause a great deal of model cleaning after a "firing" exercise.

J.

[Guest]

Hmm, i've never looked at model boats before so im unsure how suitable this would be, but possibly the use of blank ammo?

It would obviously require you to make a firing pin assembly though, but blank ammunition (8mm, 9mm, 12g, .22) is readily available and fairly cheap.

Might be worth noting though that 8/9mm and 12g blanks are bloody loud ie, not recomendable to fire indoors. For indoor use .22 blanks are more suitable, although, i doubt they would really produce much in the way of a flash, and only minimal smoke, which might be okay depending on the scale i guess.

Apart from that hmm, could suggest some kind of electronic solution? using something like a camera flash behind some orange cellophane for the muzzle flash, a recorded bang sound, and some kinda smoke machine? just thinking off the top of my head here lol no doubt others will have some more feasible suggestions!

[Guest]

5th, when he was mentioning the gun calibers i dont think he ment litterally, he ment to scale

eg. my battleship i am making has 45" calliber guns, but on the model they are 350x smaller than in real life so only mesure about 3mm accross!

so in other words real blanks would be out the question, and also in terms of cleaning they would probably burn the model and also leave residue.

i was thinking about this for my battleship but have stuck with using servos to turn the turrets.

one possible idea....caps?....again you would have to create some sort of firing pin but from what i can remember as a kid they create quite a bit of smoke and a small flash, although the sound would be a bit high-pitched to realisticly re-created the sound.

another idea....white LEDs insde the turret and sound recordings and also a smoke gen inside the model, these could all be run off a 555 timer or something but a delay would have to be put on the sound recording and the led as you would have to wait a bit for the smoke to reach the end of the turret (just thinking to myself for the smoke to be able to come out you couldnt have the LED inside, you would have to put it inside the model directed towards the turret and hope the light will travel far enough to seem realistic.)

just typing out my thoughts there, sorry...

hope our ideas help, please let us know what you think.

[Guest]

I'd assumed even on scale they might be 6/8/9mm across...6mm being a .22 blank. Looks like i guessed wrong lol

Hmm, what about some kind of fibre optics for the flash? come in really thin strands, so could be bunched up as thick as you need and lit from somewhere more convenient aswell. I guess they might not provide a very bright flash though hmm

Not sure how you'd go about combining smoke aswell hmm *goes off to think*

[Guest]

I can't actually find anything specific but I have read about in the past such things as:

Black powder down the barrel fired out with a shot of compressed gas such as from a CO2 cyliner. Only one shot per loading though.

An on board smoke generator, either of the oil burning variety or the nebuliser type, once again fired out with a shot of compressed gas via a solenoid valve operated by a servo.

I would play with the last one as it has the possibility for continued firing. Maybe a smoke generator could produce smoke for the funnel but some could be taken off into a reservoir ready to be shot out of the gun barrel.

I have also attached a picture of a model that uses led's down the barrels to produce a flash. To be honest it wasn't worth the effort as it did not look in the least bit convincing!

[ATTACH]14178.IPB[/ATTACH]

[Guest]

so is that a one of your models richard?

[Guest]

Not mine I'm afraid. Nice model but I didn't like the LED's down the gun barrels.

[Guest]

Thanks folks,

You have illustrated the kind of suggestions being made elsewhere, some ingenious possible solutions.

The real problem is getting multiple firings with the smoke/sound/flash all at the right time, particularly to scale. On most models the scale of 1;128, which gives a boat length of about 5 foot, means the barrel is only about 4mm max available inside diameter.

The other real problem is that, on the real thing, there was always a very visible fire flash from the end of each barrel, very difficult to replicate.

What do the rc Tanks use, TigerTC, Nigel?

J.

[Guest]

These sites any help?

http://www.rcwarships.com/rcwarships/

http://www.ircwcc.org/

http://www.modelwarshipcombat.com/

http://www.swampworks.com/SwampworksHomePage-2.html

[Guest]

Thanks Kiwi,

Those sites show some interesting stuff, I'm sure it would be fun to take part in a "battle".

They seem to all use the proprietry CO2 system for firing pellets, not quite what I had in mind as it's the effect that's important. We don't want to frighten little Jonny's mum, even if jonny would love to see something sink!

[Guest]

Tamiya 1/16 full option tanks use a gadet called a "Multi function unit", which does all the timing of gun recoil and proper strobe flash (not led, more like a disco strobe) they run at about £100.00.

Mark at www.mark-1-tank.co.uk has done lots of stuff with pyrotechnics for gunnery. You can give him a ring too, nice bloke to deal with.

i have never seen pyros for your scale though, someone must do it!

[Guest]

wow, those tanks are bloody amazing! very nice although when i seen the prices my heart sank lol couple i looked at cost £3500!

[Guest]

John,

I think you need to talk to George Gourlay (http://www.grmbc.org.uk/). There is a simple and effective method which works for smaller scale and is cheap and safe (compared to the American BB firing mechanisms). It involves a heated wire.

This weekend is our Start of Season sail and while we traditionally put on a pyrotechnic display we had to stop it last year and will not be doing it this year either. Otherwise you could have come to see it on operation for yourself.

At the flick of a switch there is a flash and smoke, very effective.

James

[Guest]

Tiger,

thanks, that site looks interesting.

James,

Will take a look at the grmbc site.

Like you, I find the American ways a little baffling. Trouble is they always seem to transfer here sooner or later, pity we couldn't learn to sift the good from the rubish before we import.

J.

[Guest]

I believe that basically it is a wire with a bit of oil, switch connects it to the battery, it heats up and BANG, there is a flash and smoke.