Make/wire a cheap DC smoke unit?

You might look into the Seuthe smoke unit, they can be had pretty cheaply.  I have a bunch of them from upgrades...

The ones I have run on 6V AC or DC, and draw about 250 milliamps with a brief surge of around 400 milliamps on cold startup.

To power the Seuthe smoke unit, if you have an old ATX computer power supply you can get a pair of these and hook up lots of low voltage DC items to it and put a switch in line with each circuit you want to turn on and off.  Alternatively you can just disconnect one side to turn it on and off.

https://www.amazon.com/gp/prod...le?ie=UTF8&psc=1

John

@Mannyrock posted:

Hey Guys,

  I would like to have a very cheap DC smoke unit, to place inside of one of my little buildings.

   Correct me if I am wrong (please), but it is my understanding that Marx made cheap DC steam locomotives with smoke units in them, for the smoke stack.  I remember my cousin having one in the 1960s, and it used smoke pills.   (His little sister ate one of the smoke pills and my uncle had to take her to the emergency room!)

   Wouldn't it be possible for me to buy one of these cheap locos, open it up, pull out the smoke unit, hook it up to a small DC transformer, and get it working?

Happily, I can buy a little DC Train transformer (with forward/reverse speed controller) for only $5.00 at the thrift shop train store.   (They have several Bachman's in good shape.) They also sell old Marx locomotives for cheap as well.

Thanks for any advice, admonitions, or information.

Mannyrock

In a word, DON'T.  You don't know it's condition or suitability for your purpose.  Take Gunrunner's advice - Seuthe makes smoke units for a very wide variety of uses (including specifically for placement in structures).  Exercise CAUTION.

I just recently averted a fire from a large smoke unit that failed.  Had I not been standing over it, I would be repairing / replacing a huge structure, or part of the layout, or even the house. 

George

Another option is the inexpensive water vapor mist unit.  Just a few bucks, 5v DC, puffs out water vapor just like smoke.  Great for buildings.  Just need to keep an eye on condensation.

For buildings I think the water vapor unit is a worthwhile consideration, I was quite impressed with what I got for $5, four of them!  The only thing that didn't come with it is the actual power brick cable.  You get the wick, driver board, and the emitter and enclosure.

They certainly put out plenty of vapor for an impressive building smoke stack.  You can slow down the stream by putting tubing above it, this also allows you to put the emitter down in the building.  The wick can be cut very short, it just transfers the water up to the transducer that then emits it.

Here's a quick demo.  It also doesn't need refilling nearly as frequently as a smoke unit, with the proper sized water container, it'll run for several hours without being attended to.  If it does run dry, it doesn't do any damage to it running dry.

@gunrunnerjohn posted:

For buildings I think the water vapor unit is a worthwhile consideration, I was quite impressed with what I got for $5, four of them!  The only thing that didn't come with it is the actual power brick cable.  You get the wick, driver board, and the emitter and enclosure.

They certainly put out plenty of vapor for an impressive building smoke stack.  You can slow down the stream by putting tubing above it, this also allows you to put the emitter down in the building.  The wick can be cut very short, it just transfers the water up to the transducer that then emits it.

Here's a quick demo.  It also doesn't need refilling nearly as frequently as a smoke unit, with the proper sized water container, it'll run for several hours without being attended to.  If it does run dry, it doesn't do any damage to it running dry.

That's what I love about the forums -- the free exchange of ideas!

In several recent threads, I have waxed eloquent about the potential for using ultrasonic transducers, of the type discussed above, for simulating 'smoke' on the layout. When GRJ recommended the Suethe units for the same purpose, noting that he had a bunch left over from upgrades, I wrote him and offered to buy a few to experiment with. We struck a deal, and after breadboarding one to test, I can see that, even at full retail price (about $20 or so IIRC), the Suethe units are an elegant and reasonably priced solution to small smoke simulations. The only downside is the need to periodically recharge the smoke unit with smoke fluid

Imagine my surprise, then, to see GRJ heading the other direction, experimenting with the inexpensive transducers and reaching pretty much the same conclusion I had about their potential! FWIW, I fully agree with his hot takes on the cheap misters (though I do note that, if you run out of old surplus micro-USB cords, the local dollar/5 below-type store or "slow boat" online sources have them in stock, cheap!).

Well, I've used smoke units of all shapes and sizes, but I was intrigued with the misters when they were mentioned a few months ago.  I risked $5 at Aliexpress to buy four of them, and I can see where they'd fit the bill for buildings.  Some folks have expressed concern about the humidity and any droplets they leave.  I can see that might be a concern if you get carried away with them, but I doubt one or two will have much effect.

The plus with something like the Seuthe smoke unit is the size for a self-contained solution.  I think both deserve consideration, depending on what you're environment is.  I sometimes wonder why the Seuthe smoke unit wasn't used in smoking caboose models, they're the right size, and there's less risk of a meltdown than the kludge they put in smoking caboose models now.