Building my DIY smoke machine

[signcrafter]

This has been on my list of things to make for some time now after reading this post by mechanicnamedjohn, http://www.garagejournal.com/forum/showthread.php?t=91216. My list of things to do or make is pretty long and always seems to keep getting longer. A few months ago I finally bought the 400W party fogger for 25 bucks shipped from amazon, http://www.amazon.com/dp/B0006M59M6/?tag=atomicindus08-20. I've been picking up a few fittings here and there since then to put this thing together. Yesterday I was out and about and stopped by HF to pick up a regulator for the air hook up, http://www.harborfreight.com/150-psi-air-compressor-regulator-kit-with-gauge-68223.html. It was on sale for 4.49 and I had a 25% off coupon and a free screwdriver set coupon so got the regulator and screwdrivers for around 3.50. I will give the screwdrivers to the daughter to play with for now. I was a little leary of going with HF quality on something that you want to regulate pretty low but I will see how that works and will upgrade if I need to.

So I started putting things together yesterday. I had to take the machine apart to get the front nozzle cover off. Mine was spot welded, if you could call it that, instead of screwed on like in the amazon picture.








I unscrewed the brass nozzle and it was 1/8" male pipe threads on it. I bought an adapter to go from 1/8" to 1/4" since that is what the regulator is and I have more 1/4" fittings laying around then 1/8" fittings.



On the couple of DIY smoke machines pictured in MNJ's thread they have the Tee set up so that smoke machine goes straight threw and the compressed air comes from the top of the Tee. Like this.



I was thinking it might be better to have the smoke machine come in the top/middle of the tee and the air blow it threw the Tee. I'm not an engineer so I don't have a clue but my thinking is if you have the compressed air coming in the middle of the Tee it will want to travel to both ends of the Tee equally and fight against the smoke machine's blower. Just seems like if the smoke was introduced in the middle/top of the Tee it would mix with the smoke better. Like this.



Any thoughts on which way might be better to have the Tee and where to have the smoke and air to come into the Tee?

I'm thinking I'm going to put all the parts in a small plastic toolbox just to keep everything together and protected instead of just laying on the shelf. Figure I will have some fittings and hoses, and block off plates and will be nice to keep everything together and neat. If I just put it on the shelf the plumbing or regulator will get damaged some how. I haven't decided if I'm going to "mount" everything in the toolbox so I just hook up the air and output hose or if I will just lay it loose. Kind of like the idea of cutting holes in the top toolbox tray and mounting things so that the air quick connect is facing up and the output hose would have a barbed fitting facing up and the switch be in the tray. So I just open the lid and hook up two hoses and press the button. We'll see what comes about.

Any thoughts or advice so far? I have to pick up some 1/4" pipe ******* to plumb everything together. Hopefully will get some time to get to the store to pick up a few more items this week to make some progress on this and some other projects I have going on.

 

[signcrafter]

Any advice if the smoke would work better if I plumbed it into the end of the Tee or the middle of the Tee? I would think pumping the air in the end of the Tee and the smoke in the middle it would creat a vacuum or suction effect to **** the smoke into the air stream. If I do it like the other two in the other thread with the air coming in the middle I would think the air would be pushing against the smoke making it harder for the smoke to go as far as it needs to?

 

[kenfain]

What a great idea! I just used a smoke machine for the first time today. Didn't even know there was such a thing until yesterday. Was talking to a mechanic friend this morning, asked what a smoke test was, and would it help me find the source for my lean codes. It didn't, but the machine was a cool idea. Better than how we did it back in the day. As to your question, I think it makes sense. But what about injecting air down stream, with a check valve. Wouldn't that create a suction? Kinda pull the smoke along?

 

[signcrafter]

After sleeping on it last night I am going to go with the smoke entering in the top or middle of the Tee so the air going straight threw the Tee will "vacuum" the smoke in better. If that doesn't work out I will switch it to how the other members built theirs. One concern I have is that to do what I want the smoke is going to have to go threw some 90 degree fittings, not sure if that will cause to much resistance or not. Going to the store tonight to get some more fittings and ******* to hopefully finish this up and try it out.

 

[signcrafter]

I haven't had a chance to get to the store yet to pick up the various fittings I needed to put this all together but I managed to scrounge up enough parts to put it together for a test run. I didn't hook up any air to it. Just wanted to see the fogger work.

Couple things I found out. The output gets really hot. I had planned on mounting all this stuff in a plastic tool box so I could just grab the box and hook up electricity and air and output and go. But I don't think that will work with how hot everything gets. It takes a while to warm up fully but I don't get paid by the hour at home so that is fine with me, just glad to be able to add another diagnostic tool to my garage for a price I can afford. It pumps out a decent amount of smoke once it's warmed up and seems like it has a little bit of pressure behind it.

So I'll just use the tool box to keep the machine and cords and various adapters all together nice and neat. I still want to pick up some more parts and fittings to make things a little neater but I guess it's functional for now. Pretty neat idea thanks to MechanicNamedJohn!

 

[Thndr]

Were you able to complete it? I am looking at making one as well and trying to decide if I want to use the routing you came up with or MechanicNamedJohns original...Thanks!

 

[scoostraw]

I did mine like this:

 

[signcrafter]

I did mine like this:

I like this and might have to change my piping around to make it more compact and clean like yours. Do you have a way to regulate you air pressure? Looks like you used a quick connect for the output, what type of hose hook up do you have to go from that to the car? I'd like to do this also and just keep mine in the tool box all nice and neat for storage and just be able to hook it up and go.

 

[scoostraw]

I like this and might have to change my piping around to make it more compact and clean like yours. Do you have a way to regulate you air pressure? Looks like you used a quick connect for the output, what type of hose hook up do you have to go from that to the car? I'd like to do this also and just keep mine in the tool box all nice and neat for storage and just be able to hook it up and go.

Yes I have a regulator on my compressor outlet. I also have a regulator set up with couplers that I can insert in-line, so I just configured the smoke machine with the male air fitting.

I may change the output fitting. My first project that I intend to use this for is to find an exhaust leak on my truck. The hose that I made up for the tailpipe adapter has a male on it - so I put a female coupler on the smoke machine.

But the more I think about it I think I wil change that around. The way I have it now, if the smoke machine were to be turned on with mothing connected to the output, the smoke will be blocked - and I don't want to stress the machine that way.