DIY Fog Chiller

I have owned a fog machine for many years now, but I had always wanted to make a fog chiller to get a crawling fog effect. However, due to the wind around my house in the fall, it makes it usually pointless for halloween, so until now I had held off on spending any money on it. But when low lying fog was needed for a youth play I was helping setup and run lighting for, I finally had the excuse I needed.

So before any details, a bit of physics… A simple fog machine works by vaporizing a fluid (usually made of mineral oil, glycol, or glycol and water mixture) into a heat exchanger, where the fluid is quickly vaporized. This means that fog is usually somewhat warm, as it does cool down quickly as it expands, similar to compressed air. However it is still warm enough that it always rises as it is released. To remedy this, a fog chiller is used to cool down the fog faster so it lays low and clings to the ground. Some simple examples can be found on youtube that use a metal pipe or plate and ice to cool down the fog, which to my surprise does not need a lot of ice to achieve the task. Though watching expensive professional fog machines run is rather impressive. [Check it out]

Still I wanted to do something more than a simple metal tube, so after purchasing the cheapest plastic bin I could find ($5) I gathered up some PVC tube, mesh window screen, a 120mm computer fan and a plastic sandwich bag.

As you can see from my pictures the mesh is bent and woven into a wave shape for a clear path the smoke can move through, this ensures maximum exposure to the ice is possible and allows the fog to fill the container. Next the mesh smoke path is placed between the PVC inlet and the outlet fan using the lip in the container to to hold it up. Ice is filled all around the mesh as well as in between the gaps between the smoke path. A variable voltage transformer and a remote controlled outlet is used to control power and the speed of the fan. It is pointless to leave the fan running all the time as it will melt the ice faster. Finally a plastic bag with a stiff edge is used as a simple laminar to help smooth and direct the fog to the ground for a gentle rolling effect. While I did not get a chance to take a video of it in action I have included a video of another person's fog chiller which produced the same effect. (AKA, It is not my home, and I do not own such a sketchy rug...)



I was quite happy with the results, the ice lasted and with plenty to spare, while sitting in-between uses for a good hour. And produced a good layer of fog for the two scenes that needed it. Interestingly enough a chiller seems to works better in cold air than warm, due to it keeping the fog cool longer, which is the opposite of what I assumed, as I thought it would be better to have warm ambient air to keep the fog as the cooler sinking air. Also the slower the fog is, the lower it will stay, so if you have a container to pump it into first before cooling it will help slow it, but I will save that for the v2. As you can see from my results, if you own or want a standard fog machine (quite cheap now a-days) you need to make a fog chiller, also don't buy a combined model as they only produce a slow steady output of fog, which is only is useful for an small indoor room.

Online IE Testing

I had stumbled across IE Netrenderer a few weeks ago, it is a site that lets you put a url into the form on the page and will return a picture of how that site looks rendered in different versions of Internet Explorer. For me as a mac owner this is awesome as it allows quick page testing in IE. I have been using Crossover to run both IE6 and IE7 and for the most part works quite well, however Crossover has some issues with occasional things like transparency in IE7 and can not run IE8. So for final tests IE Netrenderer is perfect for the job. As an added bonus it also allows you to do an overlay of IE6 vs IE7 for ironing out these few small differences in site layouts. Check it out for you self, if you are a Mac or Linux user I guarantee this is something you will want to bookmark.

Jyetech oscilloscope DIY KIT

A while back on gizmodo they had this oscilloscope kit for $33 from SeedStudio, which I had planed to purchase and try my hand at putting together for a while now. If it worked, although simple, it would work well for the basic circuit projects I occasionally work on. Also it may allow me to finally use the coin and dollar bill collector I have laying around. Oh, and if your are not sure what an oscilloscope is or why you would want one, click here



So after two weeks of shipping from Hong Kong it arrived and I got to work. First off I had to break down and buy some thin solder (0.32), as the thick kind (if you know me you have probably seen it) I am used to using for everything just would not cut it this time. Looking back I probably should have gone with an even thinner diameter and also grabbed some liquid flux as well, as there where a few places that the solder just refused to stick to easily. However the hardest part of the whole project was the tiny components. It was almost frightning how small most of the resistors and capacitors where when I opened the kit, and there are a lot of them to solder in very small places very close together. Going slow it took over nine hours to get everything connected and working, but was worth it in the end. Check out the picture below to see what I am talking about!



When everything was in place on the back of the board I plugged it in and checked the voltage and everything looked okay, but it was slightly unnerving as there was no way to completely tell if it would work when the panel was connected. Luckily after finishing the front side and adding the covers, I powered it up and low and behold the boot loader showed up and started graphing. Then after playing with it for a while I was satisfied that I had connected everything correctly and it was functional.

The image below is what the finished back may look like, however my kit was slightly different in that it had a few changed parts. I must confess that my connections where less nice and more painful spiky, but for my first big SMD soldering job I think I did quite well.




You can grab your own kit from SeedStudio in do it all yourself ($33), do only a little of it ($36), or already done ($49) flavors. Also I highly recommend looking at this site for more detailed pictures. I know I would have been in worse shape with out them. My final advice, you should to go with the SMD exempt kit for 3 dollar more unless you really want bragging rights. ^_^ as it quickly gets very annoying for several hours.

MIPS on Mac

A tip of the hat to my friend KDostie for finding a very decent mac MIPS simulator which you can get Here. I have only used it a few times so far, but it does everything I need it to do, and it is written in Java so there is a version for every platform. I will need it for the Computer Architecture course I am taking which is arguably the hardest CS class I have taken so far. I am a engineer, I like to use and build upon the basic theories that are already in place, not a scientist, who discovers new theories.

The Internet Archive

I am sure, just like me, others have found a site with the information they needed, however only to have it disappear at a later date. Lack of funds or just lack of interest, it does not mater, it still is one of the most aggravating things about the web, sites can close with out a moments notice, why else would I constantly end up with a list of bookmarks that go nowhere. However just like anything on the net, once it is there it stays there, in some shape or form.

To help with this, there is the Internet Archive "The Internet Archive is building a digital library of Internet sites and other cultural artifacts in digital form. Like a paper library, we provide free access to researchers, historians, scholars, and the general public."(Taken from the front page of the Internet Archive). This is a very handy tool to know of, as it can help you get to any page at almost any time that the site was available, even if it does not exist anymore.

I think it was TUAW that first brought this site to my attention about a year ago, they where showing what the Apple site used to look like over the years. I have recently needed to use the site, so I figure it is worth mentioning.