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Post by g3750 on Aug 31, 2024 14:31:40 GMT
"This will take place on my driveway."Probably a good move. Hopefully you can replicate the event and run down the problem. Frankly, I've no idea; I didn't realize smoke fluid was flammable (although I do understand most have a high mineral oil content). From the smoke unit's description - "You must have a constant power source between 11 and 12V (anything over 12v risks meltdown of the unit)". Is it my imagination or is that a tight window for operation, i.e. you gotta have nearly 12V to operate, but don't dare go over that at risk of destroying the unit.
The closest I have ever come to a flame-out was when an AC regulator feeding power to a Lionel 6 Ohm smoke unit failed causing full track power to go to the smoke unit and a very impressive but short-lived cloud of "smoke" appeared. Lionel had to "downgrade" these to 8 Ohms, which is the rating in most of the smoke unit resistors they use these days.
I know that RC boat enthusiasts use the sort of smoke generators described above and that some are used in G scale trains but I have never been tempted to try any of them. This smoke unit came from a company that specializes in RC boat and ship models. I could very easily see this putting out smoke from a ship's funnel (WWII destroyer?) or laying down a smoke screen.
George
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Post by Sir James on Aug 31, 2024 14:42:29 GMT
The ones I saw come into the store had shorted heating elements. They turn toaster red and can easily start a fire.
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Post by g3750 on Aug 31, 2024 17:39:21 GMT
The ones I saw come into the store had shorted heating elements. They turn toaster red and can easily start a fire. Thank you. I had no idea.
Can anyone recommend a metal smoke unit with some safety features built in?
I'm not saying I will install another large smoke unit in this mill, but I would like to know more.
Thanks,
George
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chuck
New Member
Posts: 45
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Post by chuck on Aug 31, 2024 18:16:53 GMT
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Post by harmonyards on Sept 1, 2024 20:37:32 GMT
We need to know the exact cause of the flames. Was there a short of some kind that has no circuit protection, and a wire caused the fire? Did the smoke unit’s resistor get glowing cherry red, and that caused the ignition? ……Any smoke unit should have safe voltage operating range. Did you modify the smoke unit for your purpose? No harm nor foul if you did, but you may want to know what Ohm resistor, and what wattage you need for your specific “custom” project. So what’s the specifics of the smoke unit you used that failed? I completely agree. I hate things that go "bump in the night". There is absolutely an explanation for this and I want to know.
To answer your questions (as best I can): - To the best of my knowledge, there was no short. But then again, I might not know what I was looking at.
- I don't know if the resistor got cherry red, but I think that's plausible as a cause.
- I absolutely did not modify the smoke unit in any way. I even buy commercial power supplies because I want that extra layer of safety that comes from manufacturing standards and UL testing. I'm not going to mess with something I don't fully understand.
I removed this smoke unit from the model and plan to hook it up to the same power supply tomorrow for a retest. This will take place on my driveway.
At this point, I am pretty certain this smoke unit is not safe to operate on a layout.
George
There’s a few do’s & dont’s regarding this smoke unit. Seems they have a big emphasis on the unit’s ability to get air flow, and don’t exceed 12V. Also noted the 2 hour primer time??……..I don’t have any experience with this brand, so I can’t say what went wrong with it. On projects like this, I like to use MTH PS1 smoke units, ….they are super simple to hook up, and work on AC power. You can dial in the voltage for a little or a lot. The nice feature of the PS1 smoke unit is at lower voltage, only one element is energized, as demand voltage increases, the second element is brought on-line. This is all done internally by the unit’s PCB. These are still available through mthpartsandsales.com ……….let me know if you need any help picking out a particular model that suits your project. Search inventory parts “smoke unit” and filter by PS1, and that’ll give you a plethora of choices.
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Post by g3750 on Sept 1, 2024 21:42:31 GMT
I completely agree. I hate things that go "bump in the night". There is absolutely an explanation for this and I want to know.
To answer your questions (as best I can): - To the best of my knowledge, there was no short. But then again, I might not know what I was looking at.
- I don't know if the resistor got cherry red, but I think that's plausible as a cause.
- I absolutely did not modify the smoke unit in any way. I even buy commercial power supplies because I want that extra layer of safety that comes from manufacturing standards and UL testing. I'm not going to mess with something I don't fully understand.
I removed this smoke unit from the model and plan to hook it up to the same power supply tomorrow for a retest. This will take place on my driveway.
At this point, I am pretty certain this smoke unit is not safe to operate on a layout.
George
There’s a few do’s & dont’s regarding this smoke unit. Seems they have a big emphasis on the unit’s ability to get air flow, and don’t exceed 12V. Also noted the 2 hour primer time??……..I don’t have any experience with this brand, so I can’t say what went wrong with it. On projects like this, I like to use MTH PS1 smoke units, ….they are super simple to hook up, and work on AC power. You can dial in the voltage for a little or a lot. The nice feature of the PS1 smoke unit is at lower voltage, only one element is energized, as demand voltage increases, the second element is brought on-line. This is all done internally by the unit’s PCB. These are still available through mthpartsandsales.com ……….let me know if you need any help picking out a particular model that suits your project. Search inventory parts “smoke unit” and filter by PS1, and that’ll give you a plethora of choices.
Yes, the Harbor Models 12V Large Smoke generator does have some "do's" and "don'ts" and I did follow them. That's why I used a commercially available, regulated, switching power supply to run it. And it did get its break-in period per the instructions. This unit had been working in this mill and on the test stand for more than a year. In fact, I found the receipt and it's dated November 2021. Here's a test run on the bench. And that's the power supply to the left.
Unfortunately, my short video of the mill running is too big to upload here. But I do have some photos of the smoke coming out of the 2 stacks.
And I am using an MTH PS1 smoke unit inside a ladle to produce this effect of pouring steel. Thank you for your offer - I may take you up on it at a future time.
George
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