Thank you for the responses! The mention of asbestos brings back the memories of school labs, we all handled the stuff, an amazingly durable material, too bad it has side effects.
Will try different smoke fluid mixes once I get a unit built, it's on the list of projects ongoing. Joe

What I use in mine is baby oil and kerosen mixed 50/50 does have a little smell but works, you could use varsol instead of the kerosen like what they use in coal oil lamps

The first time I ever made a smoke generator was in the 1960s at school - for flow visualisation in a wind tunnel I was building. There there was no shortage of power, so i used a 1/4" glass tube wrapped with asbestos and nichrome heating wire, and boiled paraffin in it - no wick. Loads of lovely white smoke once it was forced through a cooling fan - but it was oily and smelly, and not ideal for lab work....

Later when I built a Revell Bluebell corvette, I made a shallow perspex dish with the glass-fibre wick, and used the smoke fluid from a disco smoke-maker. That's essentially a glycol/water mix - much less smelly. Unless they add perfume....

I suspect that paraffin would be less smelly outdoors, though fire and an oily residue would be hazards. You should be able to get a bottle of glycol smoke/fog fluid for less than a fiver....

Dogergeezer and Captaindoug, what did you gentlemen use for the fluid? Did you buy some or did you try different homemade recipes like mineral oil or glycerin?

I am about to try building one soon as I can easily get all of the parts from things I already have. Thanks,
Joe

I made a smoke generator back in the 1990s, and used some nichrome from a broken hairdryer wrapped around a wick made from glass fibre insulation. That withstood the heat very well...

Doug that sounds a simpler way,I'll try that.
Thanks Dick

What you need is a box, your nichrome wire a wick from coal oil lamp a small fan from a computer, wrape the wire around the wick put in the oil and the fan will blow the smoke out the stack

Thanks Hammer, I will purchase one and play soon.
Cheers Dick

What can’t be seen is the small motor & fan inside the large tube.

I must confess not my idea, another members work. Here is mine, it can be temperamental. May have to suck it myself, but once it starts no problems. Do not leave the liquid part connected when not in use, as this contact can be the problem. it sometimes this needs cleaning. The photo is worth a thousand words. Any questions just ask. Hammer

Hi Hammer I've heard of this before,but no details ,I'd love to hear how you did it. Can't wait.
Cheers Dick

I have a smoke generator made from a vapour. I have never smoked myself. But me boat puffs away nicely. Will post photo when I have time.

Have just made a prototype of a fan forced smoker which seems to be working well (despite breaking the heater coil by moving it while hot, - had it apart, broke wire, screw and washer repair, not quite as hot) I bought a couple of Heng Long smokers (for R/C tanks or cars) to play with, for $10 NZ each(or 5.3 Euros to you Northerners give or take a yen) from Bangood and just bought another from Ebay. There seem to be 2 different models, as one has a long coil with a lamp wick draped over it, which is sitting in the oil reservoir, the other has a small coil inside a piece of heat resistant woven tubing (as you might find insulating toaster/heater wiring etc) which acts as a wick and that also sits in cotton wool in the reservoir, (this seems to be the better of the two) Tip - don't fill the tank right up, only enough to soak the cotton, element should be just out of the oil. The wick loads the element.
The better model seems to have a black top to the tank (also maybe either brown or black tank) and the other has a brown top and dirty brown tank. As with most of this stuff you won't know till you get it what it's going to be.
What I did was remove the tank and cut off the pump tube just in front of the screw lugs (see black line in photo) then fitted the tank, and a 40x40x10 5v ESC fan (voltage controlled by a UBEC set to 5v on the jumpers) into a plastic electronics utility box from Jaycar (our local electronics and hobby store). I made up a double JST lead for the 2s 1800Mah Lipo and fired it up (using baby oil). it's pretty much silent and smokes well once it gets warmed up, ( starts smoking in about 5 seconds)
You could control it (on/off volume) by either a remote on/off switch or perhaps a small cheap 10A brushed ESC. I would leave the fan running and control the element to avoid burning the element. The original pump tank inlet hole seems ok as is (approx 1.5mm) but you could enlarge it very slightly to get a better flow if you could find a better oil. At the electronics store they have proper smoke machine oil for $20 NZ per litre so I may have a look at that.
The reason I went for the fan idea was that I found in std pump form, if I immersed a tube from the tank in water, it sucked water back into the tank. I was hoping it would pump smoke out of my HSL exhausts at water level alongside the cooling water but it would need a very light non return valve to do this. The fan seems to pump the smoke through 2mm ID silicone tube ok, so tubing of similar ID to the OD of the tank outlets should work well.
These pumps in original form work pretty well for the price, and are cheap enough to keep a few for spare elements, the only thing is they are a bit noisy but in an 'engine sounding' way, (might add to the effect on a tug or work-boat though) What you have left after this mod is a very handy little geared motor with an eccentric output wheel which could be used for winches, radar and whirly bits of any description (see pic of motor leftover and original) To avoid burnout, these should be run on no more than a 2s (around 7.5v-(suggest 8v max with fan running)
The other tank is going to work a lot better than this one but I'm not making a tug, just want a bit of exhaust smoke on start-up etc to go with the 2 sound units. Very cheap to make (around $25 NZ with pump, box, fan and UBEC all through Ebay, Aliexpress and Bangood (and local electronics store)
if you wanted to run an ESC to control the smoke and you have no channels left to control it proportionally, you can always try using a second receiver bound to your TX, (if your TX will allow it,) power it and a brushed ESC (wired to the element) as normal and use the throttle channel to plug in your smoke control. This should work if you want more smoke as you accelerate or if you are using only 1 stick on a 2 stick TX you could use your 'elevator' stick pushed up (or a toggle switch if available) to start/stop the smoke (through the brushed ESC setup) . This setup weighs 100g (10g more than std)
The quest for lots of smoke continues Will try to upload vid later and update progress.

G'night All, Sweets dreams 😉

If it's smoke you want, I think this might just be the best available, a bit pricey, but have a shufty at the video, and you will see what I mean👍
https://www.ebay.co.uk/itm/RC-Model-Boat-12-Volt-Smoke-Generator-Variable-Volume-ESC-included-fluid-V4-S2/122319535177
Peter😉

Thanks Doug, will have
a shufti at their site. They look good
Goodnight
Rowen

Hi Rowen,
Looks very similar to what I fitted to my Sea Scout.
I bought it from Krick here in Germany. They ship round the world and very fast👍😉
https://www.krickshop.de/Accessories-Spare-Parts/Accessories-for-Ship-Models/Shafts-Couplings/Stegkupplung-kpl-3-17-auf-4mm.htm?shop=krick_e&SessionId=&a=article&ProdNr=63902&p=192
Copes with my Propdrive 1000kV on a 3S very well 😊
You can buy the basic coupler and inserts for various motor/prop shaft diameters separately to mix and match as required.
Copes with the power, is silent and slop free 😊
Cheers, Doug 😎
PS I turned up a rigid alu coupling in a few minutes on the lathe to do the setting up and alignment, much much quicker than faffing about with the 3D printer. Yes I do have one, but seldom used. The lathe and miller are quicker for one-offs.

Look good, too complicated for me though

I made them myself (and engine mounts, battery mounts etc...) on my 3D printer. I printed a solid version to line up the motors then replaced those with the flexible ones afterwards.

Good looking destroyer, the prettiest of all in my mind. What type of shaft couplings are those? Look rather unusual

A bit of confusion over what i wrote last night (note to self dont mix the internet with rum) I did not use a piezo unit, I used ultrasonic units, the kind that are fitted to fire places to produce the smoke and flame effect. The water depth seems to be the critical factor in the amount of mist produced. I am not looking for masses of dark smoke just enough to simulate diesel exhaust. This was just a prototype that works quite well but I am going to revisit it and try to improve the output and look for an ultrasonic unit that will work at 12v

Mine is still in the "pile of bits on the bench" stage but when I figure out how to package it I'll post some pics.

The model it's going into is HMS Cadiz, battle class destroyer which is around 1:96 scale so there's not a huge amount of space available, especially as the funnel is currently above the radio gear and batteries so I'll need to pipe the steam from the spare compartment I have nearer the bow.

Thanks landie.
I had assumed that Marina's is a home brew job since he wrote that he 'made a smoke generator'.
Some pics of your version would be nice👍 What model?
Cheers, Doug 😎

I assume marlina2 is using the same as the one I linked to, no circuit required other than a 24v supply. The fan speed and the depth of water over the transducer seem to be the key factors in how much vapour is produced.

I’m using a single funnel and twin transducers in mine, if I ever get it packaged small enough to fit in my model !

OK landie. A known technique.
So it's a steam/water vapour generator, not smoke.
No wonder it's not too visible.🤔
Would be interested to see the circuit that Marlina used to generate the ultrasonic waves in his home brew version.
Nevertheless, think I'll stick to 'oil burners'.😉
Cheers, Doug 😎

It is a piezo speaker, no spark involved or heat of any kind. it uses an ultrasonic wave to vaporise water.
For example...
http://www.wicksteedparkmbc.com/smoke-generator.html

Hi Marlina,
I'm intrigued! How do you use a piezo transducer to produce vapour/smoke?
Where does the 'squeeze' come from?, and how does the miniscule spark (ca 1mm per 3000V, if you're lucky😉) produce vapour?
What 'fuel' do you use? Oil smoke or water vapour?
The P68S is clear, typical good quality from A.E.
Cheers, Doug 😎

I have made a smoke generator using a piezo transducer and a P68s variable speed brush less fan controller from action electroncs. The transducers tend to be 24v dc and are relatively cheap (£2-£3 each). I am using S3 lipos so I only have 11.4 available but a very cheap variable output unit gives me 24v. The fan is connected in-between the receiver channel for the throttle and the speed controller. The fan speed increases with the throttle and follows the throttle speed regardless of direction. The net effect is quite pleasing for diesel exhaust simulation, with a steady stream when the stick is centralised and the fan just idling. On fwd/rev throttle movement you get an increasing amount of exhaust dependent on speed. I have this installed in my Forceful paddler with twin funnels. The effect is quite realistic but can be difficult to see. I am looking for a another transducer that will produce more vapour. in its present configuration it will run for around 3 hours before topping up is required.

Good idea using a glow plug,I'll try it soon with baby oil.
Thanks Dick

Been thinking how I could build a compact sealed electric smoke generator with a pump to push the smoke through the exhausts, along with the cooling water on my HSL.
Are the model train smokers not big enough for your purposes. You could just copy one of those and enlarge it perhaps. From what I remember from my train days they were not too complicated. How about an upside down ic glow plug with a variable voltage regulator in the bottom of a tube with a low temp oil ?
You could possibly use a small brushed ESC for the regulator and come up with a controlled drip feed replenishing system. Just seen a site SMOKE EL in Germany which makes smokers for ic and electric planes but they look expensive and complicated,- work well though,-vids on site.

I'm in the middle of building an ultrasonic generator, tests so far look good but only played with it on the bench.
Just add water... so easy enough to refill and costs nothing.

Hi Dick,

It's a small smoker.
So, I figure it probably smokes for about 45-1 hour!

The one I have. smokes for 3 hours.
On one fill of smoker liquid!

But maybe you can call Cornwall Model Boats.
And ask some questions!

01840 211009
Cornwall Model Boats Ltd
Unit 3B, Highfield Rd ind Est,
Camelford,
Cornwall,
PL32 9RA,
United Kingdom.

Cheers, Ed

Thanks ed just checked YouTube, not quite sure how long smoke last.

Hi Dick,

No I haven't made one!
I purchased mine from Harbor Models in the US!
You didn't mention how many volts your tug will be!
But what about something like this!
https://www.cornwallmodelboats.co.uk/acatalog/graupner_2324.html#SID=253

Cheers, Ed