Just about a week ago we finished making a fog machine that can produce a WHOLE lotta fog. It was made for the NoTrollsAllowed hackercamp and everyone loved it. It’s always exciting to go into a tent where you can’t see anything in arms length :D
The idea popped up when we were trying to think of something new to bring in for NTA and we were inspired by a YT video.
And we did much of what he showed the same way from parts we found laying around in the workshop. Only thing we bought were a capillary copper pipe and pumps.
This is the video – big thanks to that guy :D :
Making the fog machine
The first thing we did was make a forge to melt aluminum. Old one was busted and this was a chance to build a much better one.
Meanwhile we took the heating elements and hammered them into shape. These heating elements are 600w each, so we put together 2 of them together to have one 1.2kW heating block (it draws 5A of current) – makes the whole block heat up faster.
After that we made a copper coil where the smoke fluid will go through, put heating elements inside and poured aluminum on them.
Unlike in the video, we made a multi-use mold and took the whole block out.
Lesson learned here – don’t leave aluminum in the forge for too long, it’ll start to glow bright red and will melt through copper.
So now once the first heating block was done, we wanted to see just how effective they are.
I bought smoke fluid from the store to act as a base we could compare against once we mix our own fluid later and we tried a bit in the workshop using a syringe to inject fluid. It was so much fun that we decided to fill the whole workshop and then had some more fun with lasers :D
Just for this test we monitored the temperature with a multimeter which is capable of measuring it. We learned that it can make a lot of smoke in a very short time.
Then we went ahead of made two more of these heating blocks. There were supposed to be four in total, however as we were nearing our NTA deadline we didn’t have time to make another one. That was probably for the best because with three blocks we could connect each of them to a different phase socket as to not overload the electrical breakers.
So anyway, we now had three blocks in total, wrapped them with insulation and added 300C thermal-switches that turn off heaters once they reach that temperature and turn on again once the temperature drops to ~260C. And of course we also tried all of them together, but outside this time :P
And this time we used a fire-extinguisher with 1l of fluid and 18bar compressed air.
After a couple of tests it was clear that we made an actual monster fog machine.
Time to build a case for it.
Since the whole contraption was supposed to be temporary (because we had a very different idea in the beginning but didn’t go that way because deadlines :P ) we used simple MDF board which expands and crumbles when they get moist :D but they held up pretty well during the whole event.
Making electrical connections, we wanted to have a possibility to use any number of heating blocks, in case we bring this contraption somewhere where we can’t get enough power, therefore a relay had to be used. And obviously you need to somehow know when they are ready to use – for that we added indicator lights. But because we didn’t have actual indicator lights that work from mains power, we just used halogen bulbs with yellow paint (we tried to use just acrylic filters glued on with epoxy but those fell off after a while). But those bulbs shined too bright, so we added a diode for each of them to decrease their wattage.
Pumps that were used are replacement parts for smoke machines up to 1.5kW of power. Since our heating blocks are 1.2kW, we had a bit of reserve.
To control everything though, a removable controller was made from a cordless drill. It connects to an XLR type of connector. And looks like something a terrorist would use along with his bomb vest :D
Finally a rear bumper was added to protect copper pipes and front cover was added to protect people from touching anything inside.
And now it was pretty much done.
Making the smoke fluid
Considering the amount of fluid it uses it’d be effin expensive to buy ready-made fluid, because it costs ~20eur/5l. A much better alternative is to buy glycerin and mix it with water 30-70 (30% glycerin and 70% water) or 40-60. The amount of glycerin you use determines how much smoke you’ll be putting out.
We also tried mixing Propylene glycol with water and with glycering too, but the difference in our tests were very small. We decided for our purposes just glycerin will be ok, and it’s cheaper too.
So, 20l of glycerin from berchem.lt costs 50eur without tax and delivery and you can make a lot of smoke fluid with this amount.
We also tried experimenting with different smells by adding concentrates used by vapers and that actually works really well. You’d need a very small amount for 1l of fluid to notice the smell, but eventually it got annoying and plain odorless fluid was the best thing.
And we also tried experimenting with food dyes, hoping to make smoke colored, however that went very bad, because apparently the whole added color burns to the sides of a pipe and comes out the other end as black tar. Smoke doesn’t become colored. Don’t do that :P
When we brought it into the event to be used and abused it was used quite a lot because everyone loved it.
The event is held at a large campsite with trees all around and a large lake. We stayed for 2 nights and during the second day the machine wasn’t turned off since morning till late at night and held up very well. In the second day, at night there were practically no wind and it was absolutely amazing – the smoke would fill up the whole campsite to produce a fog that looked very mystical with dark-ambient music played by DJ’s in a tent.
And here are some nice photos from the event, not made by me:
Ok, so we took the machine to the same event this year as well and after some time using it when we left it unattended, the thermal switch on one of the blocks just decided to break and never turned off the heating elements. They reached a high enough temperature and self destructed basically, by melting the aluminum and burning much of the inside. Luckily though, one of the blocks was in a good enough condition to work again for the last time.