ideas for making smoke/fog

Hello, I'm looking for ideas for making a bit of smoke or fog for a magic trick. The smoke/fog is to be set off with an Arduino. So, something I can set off with less than 40mA (but can use a transistor if more current needed). The amount of smoke is really just for looks, and can be very little. Say...equal to about 10 puffs of a cigarette. That's the SI unit for a measure of smoke, right? :).

Other criteria: 1) smoke/fog must be non-toxic 2) Prefer odorless, but some smell ok 3) Must be safe 4) Color: white, but can really be any color, I don't care. 5) Size limit: I'm somewhat limited by the size. I can't use a beaker of material with wires running out of it. Needs to be about the volume of 4 matchboxes max. Prefer something non-liquid. Ideally, it would just be a small matchbox size thing with wires running out that would emit a bit of magic smoke.

Have you checked your local hobby shop where they sell model trains? The steam locomotives (at least some of them) puff smoke. You can buy the liquid there that makes the smoke. Don't know what you will use for the heating element that heats the liquid turning out the smoke. A car cigarette lighter will do it but takes a lot of power at 12 volts. Probably overkill.

Maybe the heating element from an e-cigarette.

The same hobby stores will sell smoke generators as add-ons for trains that don’t already have them. They’re all going to use more than 40mA…
http://www.onlytrains.com/model/trains/65853.html
(beware sticker shock!)
There was a guy running around with something like this, connected to a battery, in his pocket. At a fireworks convention: terrifying!
(10 puffs of a cigarette sounds like quite a bit of smoke to me…)

In the UK smoke liquid can be had by the litre from local Maplins.

Just need a heater then.

Else try a music/disco supplier.

Thanks for the ideas, all.

Looking at how these work, I think these liquid smoke things need too much heat? I’m powering the thing from 4xAA batteries. I only need a bit of smoke…but this still might be too much current to draw.

For a cigarette puff you only need a very small drip of fluid hence a small heater.

EricExperiment: Looking at how these work, I think these liquid smoke things need too much heat? I'm powering the thing from 4xAA batteries. I only need a bit of smoke...but this still might be too much current to draw.

Most likely 4 AA cells won't get you very far, unless they are LiPo or similar - something that can take a heavier current draw. Maybe NiMH would work...?

For the smoke - you might look into vape juice (ie - e-cigs - but not the commercial brands, you'll want parts meant for "box mods").

At its core, vape juice (and most fogger liquids) are combinations of poly-ethylene glycol and propylene glycol; for your small needs, just getting some standard vape-juice from an online vendor (or a shop) will work ok - just be sure to get the juice with zero nicotine in it. You can get it flavored as well (there seems to be infinite flavors) - which in many cases leave a pleasant smell, depending on the flavor of course.

In order to purchase the juice, though, you need to be of proper age to buy it (which will vary based on your local jurisdiction - here in the United States, there isn't a set legal age for vaping products, but most of the industry has settled on the same as for traditional cigarettes and tobacco products - 18 years of age).

Once you have the juice, you need a way of making the smoke. This is done with a simple heating element, called a "coil" in vaper parlance (there's a whole hobby of vapers of making custom e-cig equipment, winding coils, etc - its on par with the custom PC case modders) - which is made out of nichrome wire. This coil is either wound bare, or around something to soak up the juice - like a piece of cotton, sometime fiberglass, sometimes a small porous ceramic tube.

The way the e-cig or vape pen works is that this "wick" is soaked in the juice, and the wick carries it to the coil. When a button is depressed, current is run through the coil, which heats it up, causing the vaporization of the juice into a "fog" or "smoke", which is inhaled (thus imparting the nicotine hit, plus flavors if any - it is also possible to get a pure caffeine vape juice plus flavor, but there is debate on how well, if at all, such a juice works).

You would need to replicate this in some manner - you would want some kind of compressed air source to basically flow up and around the wick and coil, and a way to electronically control the flow of the compressed air (maybe the air comes from a pump, or a bottle and you use a solenoid valve or similar). Your code would first start the air flowing, then turn the current on to the coil - after a few seconds or so, turn the current off to the coil, then shut off the air flow. You need to keep the air flowing properly, and also regulate the current to the coil, so as not to burn the wick or the juice (which in an e-cig tastes horrible - and smells just as bad).

Note: If you are using LiPo cells - you will -definitely- want to carefully regulate the current; the nichrome coils present an almost dead-short across the cell or battery involved (the coils have fairly low resistance - sub 25 ohm is actually a high value), and you don't want to exceed the C rating of the cells if you can avoid it, because this can lead to damage of the cell, and ultimately to fire and worse (LiPo cells are not something you can be cavalier with). In fact, if you have heard anything about users of vaping or e-cig products having their e-cigs "blow up" in their faces (this is real) - it is almost always being caused by users who homebrew a custom box-mod system without any form of a regulator on the coil; this causes extreme stress to the LiPo cell(s) involved, which ultimately leads to the cells going into a "thermal runaway" mode, causing a fire, venting, exploding, you name it - in a device near the users face. It also doesn't help that the cells they use are sometimes cheap cells that are re-badged seconds from a reputable manufacturer, which are bought by the truckload, re-labeled (sometimes with higher C values than spec!) - and sold on to the hapless user (who may be box modding and not know anything about ohm's law - not that it would help the person, if the cells have been mis-labeled). This is also the same issue behind the exploding "hover boards" in the news as of late.

So - be very careful if you go the LiPo route - or avoid it, and go with NiMH cells.

A big guide to smoke here: https://www.youtube.com/watch?v=H5QtGerJ_tI Thanks to Big Clive :)

And another guide here.

:astonished:

lol. You guys are the best. Thanks!

EricExperiment:
Say…equal to about 10 puffs of a cigarette. That’s the SI unit for a measure of smoke, right? :).

Should the unit for smoke not be a “Hack”? :grinning:

Here's a YouTube Video where the hacker makes a smoke generator from an e-cigarette. (Warning, he takes 15 minutes to make a three minute tutorial).

To trigger this from an Arduino, you will have to use a relay or FET because the heating element draws more current than the Arduino digital pins can provide.

I just did this for a friend who asked for the same thing (Halloween costume)

He sent me some tutorial (cause he says he cant solder things himself)

Basically:

Vape tank/cartridge fish pump/motor 'fog juice' (non-toxic.. not nicotine) some tubing and hot glue.. and a battery with HIGH current/mA rating..

I -just- posted on this seeking advice on the MOSFET I had laying around vs 'the one I should have used' LOL

SteveMann: Warning, he takes 15 minutes to make a three minute tutorial.

Entirely par for the course!

xl97: 'fog juice' (non-toxic.. not nicotine)

Not necessarily so, according to the recent medical commentary on the matter!

(Vaping suggestion by Escobar19 deleted, looked too much like vaping spam to me.)

Paul__B: Entirely par for the course! Not necessarily so, according to the recent medical commentary on the matter!

I mean the package of course could be lying. But to be clear.. the stuff I used/mentioned (whic was for a costume/special effect) is not for inhaling either.. its not a nicotine product. it purely for 'fog machines'.

(and again.. the package could be lying, but it said non-toxic..etc)

Recent medical studies (not always original studies, often "meta-analyses" which are of little value in themselves according to my training in Medical Statistics - many years ago for that matter) are concerned that the glycol itself and particularly the many "flavours" offered for vaping, are problematic when heated. So there may be a concern.

The fact is that nicotine in itself, is a relatively minor concern - which is why NRT actually carries minimal risk!

The worst problem turns out to be people who "vape" and continue to smoke tobacco. :astonished: Completely defeats any purpose of vaping as a valid "harm reduction" approach to addicts.