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[C-3PO]

Geoff,

Do you want an off the shelf sound or would you want to load your own?

Also do you want to be able to trigger bang 2 whilst the  bang 1 is still sounding? ie you fire another gun quickly after the first and both sounds play out to their end

C-3PO

[Geoff]

Off the shelf should be fine but it depends on the difficulty as my IT skills are limited. I intend to be firing broadsides of 5 guns at a time so ideally a staggered rippling blast lasting say 2-3 seconds would be best but a single blast would probably suffice.

[Bob K]

Of preference I would prefer a 'standard' smoke generator element, rather than trying to make my own which could be more dangerous than gunpowder (ship aflame or infinite current).  I am still not sure if the two part tubular sleeve valve is for the barrel exhaust, inlet to the barbette, or both.
I have a replacement 'Sparkfun' air pump on order as the 'spare' I trialled may have been water damaged.  Maybe I can get the e-cigarette idea a stage further. If I suck on it then blow it down the tube it seems quite effective.
If rotary 'petal' valves were not successful it could be very tricky getting the turrets to rotate and guns elevate whilst still retaining reasonable internal pressure?

[Geoff]

Making your own element as its just the same as used in the commercial smoke units - it really isn't an issue as you use a non flammable wick which sits in non flammable fog fluid - it basically boils it off creating the smoke. If the element gets too hot it just brakes without any drama. If there was a direct short for some reason this is protected by an in line fuse.

Fire could be caused if you used any type of oil rather than fog fluid and years ago that was a problem. To the best of my knowledge none of the commercial units uses anything other than fog fluid even if its called "smoke oil".

I have used this system of smoke generators in a number of models for years and never had any problems. If the container is made of plastic card its necessary to use an alloy heat shield over the top of the element but otherwise its really no problem.

My solution of the two part tubular valve would be one at the base of the gun and the other just outside the fan, The concept being the fan valve opens the fan kicks in and pressurises the whole system (we are talking very low pressure here) and then the gun valve opens and the smoke is ejected in a puff.

The valves can be located in any convenient location but the gun one must be between the barrel and the smoke box.

Experience showed that when I used a PC fan into the smoke box smoke was forced back past the fan hence the need for a second valve to stop this.

Hope this clarifies.

Geoff

[C-3PO]

Home made Smoke Oil

Does this make sense - any comments? - Found this on instructables - so I is not me it's the author :)

What you need
- Glycerol, Glycerin or Glycerine (same thing)
- Distilled water
- Measuring jug
- Container to store solution

Step 2: Where to get your ingredients from

Gylcerol, Glycerine and glycerin are the same thing. It is easily and cheaply obtainable from your local chemist. Either behind the counter or on the shelf, you will find it next to the throat medicines as this is one of its uses -- eases discomfort from harsh coughing. It will also make you more than regular if you drink too much of it!

Distilled water should be easy to come by. Places like Halfords (England), or outlets which sell car consumables should sell this. At a push you can get away with dionised water. The aim here is to get a water that is about as free from lime and other impurities as possible.

Step 3: Method

For high density smoke...
Make a solution of 30% glycerol. The remaining 70% is made up with the distilled water.

For medium density smoke...
Make a solution of 20% glycerol. The remaining 80% is made up with the distilled water.

For low density smoke...
Make a solution of 15% glycerol. The remaining 85% is made up with the distilled water.

-------------------------------------------------------
For purposes of clarity, should I want to make a solution of high density smoke fluid I would simply pour all of the glycerol into my container. I would then fill the empty glycerol bottle with water and pour that into my container. I would then do this a second time to achieve (roughly) a 30/70 mix of glycerol to water. You don't have to be exact with this.
-------------------------------------------------------

Once you have poured the required amount of each liquid into your container, shake for a few minutes to ensure that the two have completely mixed. You now have your own smoke fluid at a fraction of the cost of commercial smoke fluid.

Step 4: Preservation

You may find that you want to keep your smoke fluid for a period of time. If your container is clean, and your smoke machine doesn't already have traces of mould in it then you should be ok for about a month. Less if you have made up a solution that is less than 30% glycerol.

Anything past a month and you may want to add a preservative (antibacterial agent) to extend its life. Given that this solution will eventually be aspirated and breathed in, it is important that you don't add too much of something, or the wrong thing for that matter!

I would recommend simply adding 2-3 drops of bleach to every litre. This will keep any chance of infection down and will still be safe to people in the concentrations given out when it's used.

[ballastanksian]

That looks like what 'Big Clive' on Youtube was using to make vaping fluid. You have the benefit of not needing to worry about the flavour additives that can have wick damaging oil in it. Glycderine is cheaply available from chemists like Boots.

https://www.youtube.com/watch?v=MTI0CuPvOB0

[C-3PO]

I think I will have a go and report back on my findings - all experiments will be conducted outside so currently rain stops play!

Regards
C-3PO

[C-3PO]

Geoff,

Have a look at this - is this the type of thing you would like to achieve -  https://youtu.be/t9P3ZJBE53g

In this example there are 5 separate sound files each individually triggered. Up to 14 files can play simultaneously. You might just be able to make out the previous bang has not finished as the next one starts.

The final sound file needs some echo/reverb added as it ends very abruptly. Sorry the quality isn't great partly YouTube compression but also the fact that I fried my little amp earlier - this sound is recorded playing through non bass friendly headphones.

C-3PO

[Geoff]

Close but a little sharp as I need more of a rumble. Google Iowa firing 16" gun and there is a u-tube video of  a salvo of three - almost perfect!


Cheers


Geoff

[rsm]

Ram in the US make a 16" gun sound unit:


http://www.ramrcandramtrack.com/ramdemos/ram81/ram_81demo.html


I think they are marketed as Admiralty Electronics in the UK, available here:


http://www.model-dockyard.com/acatalog/Admiralty-Electronic-Accessories.html
http://www.cornwallmodelboats.co.uk/acatalog/admiralty_sounds.html

[Martin (Admin)]

Geoff,
Have a look at this - is this the type of thing you would like to achieve -  https://youtu.be/t9P3ZJBE53g
C-3PO

Very impressive!

[Geoff]

These are exactly the ones that I'm most interested in because I can trigger them with a micro switch but they only have a 2" speaker. Does anybody have any experience as to how loud they actually are? For example could you hear it at 50 feet away on the pond?


Thanks




Geoff

[rsm]

They are pretty loud, but you could always put a bigger speaker on if you have the space (just make sure the impedance is the same). I have the 16" gun sound in my Yamato and the destroyer whooper in my Solebay.

[C-3PO]

Geoff,

Very happy to be proved wrong but I would suggest you would be underwhelmed by the sound for a couple of reasons. The 2" speaker just won't move enough air and also the sound file I listened to doesn't seem to have much dynamic range- more whoosh than thump

I am no expert here but I have played with sound files and boats for several years and even with an efficient 2x20w audio amp into two decent quality 4" speakers unless the sound is ported well to the outside world it can be hard to get the result you want.

You are pushing the envelope with your smoke development - I don't think this solution will sit well with that - sorry!

C-3PO

[Geoff]

The 2" speaker size was my concern as well. On ID I have room for a 4" speaker under the forward superstructure. I have left the back at each side open so sound can get out. I also have room for another 4" speaker under the aft superstructure. The deck for this is wire mesh so should provide room for the sound to get out. I had, to a degree, thought of the problem or porting the sound during construction.

I've also seen some mini Bluetooth type speaker units which seem to give good sound but again I'm somewhat old school and figure large speaker = loud noise but I know with todays technology this is no longer a hard and fast rule.

Thanks

Geoff

[tigertiger]

Larger speakers make more noise?

Kind of true but a lot depends on quality and power of the speaker and amp.


Amps being the same, quality of speaker is important.
Output for 50mm speakers available on Amazon is range 0.5W to 5W.
Output from 50x90mm oblong speaker 10W
Output from 100mm speakers varies from 8w to 100w.


Other consideration, will the sound unit put out a pre-amplified signal? If so you can put in a bigger amp.


Other things to consider.
Frequency response, you don't want all tweet or all woof. If you can find a 100mm co-ax speaker it might be a good option. These usually only come in pairs, unless you can find an old car stereo with one duff speaker in the charity shop, or free ads paper.

Weight. Anything from 200-500g for a nice quality speaker in this range. Placement of this weight may be fixed and so the other ballast needs to be planned around it.

[C-3PO]

Agree 100% with co-axial - I use these

SONY XS-GTF1027 - About £32 pair on eBAY - IMHO -  a great option

And I use this amp - http://www.maplin.co.uk/p/adafruit-stereo-20w-class-d-audio-amplifier-max9744-a54qn or I did until I fried it - another one on order

C-3PO

[Geoff]

Now that seems very interesting, so if I got the 16" gun sound module I could then connect it to the Maplin amplifier and power two larger speakers?


How do I tell if the gun module is pre amp or includes an amp and what difference does it make. If the gun module has an amp why can't I still just connect it to the Maplins amp and boost the signal further? Electronics are not my strong point here!


Thanks


Geoff

[Geoff]

I should have Googled before I posted. The answer of course is an amplified output going to an amp input will overload the input side and fry it so it won't work. does anybody know if the gun sound units are amplified. I can't talk to the seller given the time but may call them tomorrow.


Thanks


Geoff

[ballastanksian]

Could you use the hull it self as a speaker? I am sure I have seen or heard of flat speakers somewhere. therefore you coulduse the hull which is much larger and might give you some bass quaity to get the deeper tones of large bore guns firing.

Could one of these work? https://www.youtube.com/watch?v=YvQzxcYZuss

[g6swj]

The exciter/transducers do work quite well when attached to virtually anything however anything loose in the boat/ superstructure etc lets you know it's there and can be quite annoying as it rattles away!


In theory the admiralty sound module amplified output could be matched to another amp input but it is not ideal, it may be possible to pick up an output at an earlier stage/lower level of the sound production

[tigertiger]

It might be worth asking on an electronics or hifi forum.


OR
Ask one of the guys at your local Maplins (if you have one) if they know a guy who can. Probably worth the investment.

[C-3PO]

Google

speaker output to line input

not sure the little sound card will have enough output to drive this type of device.

[tigertiger]

not sure the little sound card will have enough output to drive this type of device.

Not well versed in this topic, but.
Isn't that the pre-amplified signal?
Won't the amp then do the work?

[C-3PO]

I think Geoff wanted to plug the amplified sound card output into another audio amp

These "speaker output to line input" are a dirty fix to take a amplified speaker level signal and drop it to a line level one so you could plug it into another amp.

Don't really see them much these days they get used where you don't have a line level output only amplified speaker signal on the source device.

"high-level to low-level signal converter designed for devices that do not have dedicated low-level outputs"

eBay have some for a few pounds so may be worth the gamble

C-3PO