Miniature smoke machine

[grandmasteralok]

Hi,
I play R/C cars as a hobby, particularly R/C drifting... it's been months since I have been experimenting how to make artificial smoke to make my car more realistic while running... This forum provided me great assistance building light units for my R/C cars... This time, after running out of ideas and resources, I hope this forum would be able to assist me again...
Basically, I want to build a miniature smoke machine to equip my radio-controlled car... it will be powered by a 9v battery... I will be using a liquid smoke (smoke oil) that will be heated to produce the smoke...
Please refer to this link: **broken link removed**
The "Smoking Mk III" is better... they claim that it is powered by a 9v battery, which is feasible since the device is used in toy trains... I hope someone would be able to help me build the machine... or at least a heating element that can be powered by a 9v battery...

 

[HarveyH42]

Link didn't give any specs. on the smoke machine or oil.
**broken link removed**

Not sure a 9V battery would last very long, with the fan and heating element... Need to figure out what temperature you need to achieve for smoke, then a means to regulate it. Don't know if the oil is corrosive, but should be simple to find (old toaster, glow plug, lightbulb). Could use PWM to control the temperature/volume smoke. Think it would take a little experimenting to bring it all together, but got a hunch it'll still run through some batteries quickly.

 

[zipdogso]

I would just use a small box and fan. have the Rc somehow open the box and start fan. Just put dry in the box. i.e. a miniature version of the smoke effect at discos etc.

 

[ronv]

Smoke

I'm guessing you are going to run this off of your rc battery?? If so 9 volts and how many amp or milli amp hours is the battery.
Maybe the next step is to find out something about the temperature needed to make smoke and how much can be made.
I think I would start with 2 resistors (heating element) a 10 ohm 10 watt and a 100 ohm 1 watt. These should both get real hot running on 9 volts. Hook each one across your battery and see if you can boil off the oil. Hopefully the 1 watt will make enough smoke. If it does we can make a simple pwm to adjust the temperature.

 

[Sceadwian]

Smoke oil is generally meant to be injected into the fuel line of nitro RC cars, you're going to find it a horrible waste of your RCs battery life to do this. This stuff is used on scale trains to make little puffs of smoke but the heat you'd need to make a constant stream of smoke at the speeds an RC car goes at are going to be quiet high. This seems like a good excuse to me to convert to nitro => Get some real power under that buggy

 

[grandmasteralok]

Thanks for the response... well, basically, all I need is the heating element...
The fan will be powered independently, same with the heating element... I am planning to use one or 2 9v batteries for the heater...
The oil I will be using is the same one used in smoke machines... as to how hot the heater should be, I really can't say... maybe start from relatively low going up high...
I think if we could come up with a diagram for a heater alone, with heat limiter if possible, I could put everything together already...

 

[HarveyH42]

Did a quick search, seems like any light oil can be used, baby oil, mineral oil, lamp oil... didn't get any temperature specs yet.

 

[ronv]

pwm

Here is a link to a pwm controller. Just put an 18 ohm 5 watt resistor (Heating element) where the motor is and you should be able to control it's temperature between room temp. to 350 F.
**broken link removed**
The fet may be hard to find. If so you can substitute a stp27n3lh5 from mouser. The resistor 280cr518rc is also available there.

 

[Dr_Doggy]

why not use induction heater too, more efficient?

 

[Sceadwian]

Howso doggy? Induction heating isn't practical on that scale and normal heating coils are 100% efficient anyways.

 

[Dr_Doggy]

induction is more efficient, just cause he wants to save batteries at any rate, plus look at that big contraption up there, an induction system you can small down some, plus he only needs to go up to 300celcius max, so all he really needs is a few iron filings into a jar of his oil, with a small coil around it,

was just a rookie suggestion anyway,

 

[Sceadwian]

doggy all electric heaters are 100% efficient. Induction or resistance... Induction heaters are only used when a specific metal object in a coil needs to be heated or for uses that require the heating element to not be in direct contact with the target (which must be electrically conductive). For the purposes of heating an element in a liquid such as the smoke oil, induction heating would increase the complexity size and not be any more efficient. Actually technically induction heaters are less efficient because they end up broadcasting some of the energy that would otherwise go into heat into the local environment as magnetic/RF energy. They're used because they don't need to physically touch the piece to be heated and they only heat metal or other highly electrically conductive substances.

Nothing wrong with suggesting anything doggy, rookie or otherwise, just take the response positively and learn. Aside from some isolated incidents we users here are here to learn, and if you said something that ended up being not the way things really are all the better because it means you may learn something new.

 

[grandmasteralok]

Thanks ronv, but unfortunately, no electronics shop in my place knows the mosfets... I am located in the Philippines, by the way...

 

[ronv]

I used to go to the Philippines all the time when I worked for Sunward. If you can find the other parts we could substitute a transistor. I'm in the US -- the desert of Arizona.

 

[ronv]

A PS. Do you think 350 F. is hot enough?

 

[Sceadwian]

It depends on the exact smoke oil.

 

[grandmasteralok]

@ronv - I think so... you have an idea???

How about battery operated soldering irons??? I've seen the coldheat one... but really not willing to purchase and dismantle it just to end up with junk... can I build one like it out of scratch or improvise one???

 

[HarveyH42]

Looked up the MSDS for Baby Oil. Boiling point is >500 F, Flash point is >200 F. Have to look up some other oils, but a little slow on dial-up...

 

[Sceadwian]

The Coldheat is nothing more than a graphite current passing element, it doesn't directly heat the current it passes heats, there's not much else to say. To get those kinds of temperatures concentrated on a small scale, you'd need a find heating coil and great mechanical design.

 

[ronv]

Yep. Think your right. Here is the quick experiment.
3/4 ounce of mineral oil in a metal container.
2 10 ohm 3 watt resistors running at 14.5 watts submerged in the oil.
Oil temp after 20 min. = 220F. No smoke -- good heatsink.

Remove the resistors from the oil and of course smoke.

Conclusions: It would take to much power to heat a volume of oil. What would be needed would be something like a drip system.
Observations: Looking again at your videos. In the first it looks like 2 12 volt 7AH batteries running the smoker. Also it is a big train not a little model. The point being lots of power.
Anyway. more ideas needed.