Help With 3rd Rail Sunset Model Smoke Unit

It appears that the ceramic coating is still on the element (resistor). This needs to be removed very carefully. Some new wadding and fluid should put out tons of smoke.

Good Luck.

Oh man.  Good catch Jayhawk500.  I didn't even notice that.    I'm going to remove that and report back.

On a side note:  I see what people mean by needing to be an expert to work on these 3rd rail engines.  Very difficult to work on but a good learning experience.

Ps.. What's the best way to remove the ceramic coating safely?

Put in a new 20 or 27ohm resistor, it would be easier,  hos is the batting in it???

Marty

I use a 6" wire wheel. Most folks use a dremel and a wire wheel. Use a very light touch on the coating and just expose the wires. Just be very careful.

I replaced the batting in it last night.  I'm taking the smoke unit out again.  Hopefully I can figure out how to take the ceramic coating off.

OK, got the bottom portion of the coating off (the part that actually makes contact with the batting).  Now, I fire up the transformer and Legacy controller, train fires up with sounds but won't move.  Train is equipped with TMCC.  All functions worked last night. 

On my Legacy controller, on the bottom right of the screen where you pick your engine number, there's an arrow pointing down.  Usually this arrow is pointing left or right for direction.  I've never seen it point down like this.  Any ideas why???

TrainGuyMcGee posted:

I've recently acquired a Sunset Models 3rd Rail steamer and dissected it to clean/lube/inspect.  Part of the reason I did this was because the smoke output was less than anemic.  It was used so I figured it may need a new wick.  While I was at it, i went ahead and drilled out the smoke intake to 1/4 inch to allow for greater air flow.  After reassembling the locomotive, there was no noticeable difference in the smoke output.  So my quesiton is this, can an MTH smoke unit replace this one?  See pics below for smoke unit type.

Replace the resistor and the batting.

Lou N

Lou, do you happen to know the part number for that resistor?  Is there a comparable replacement that doesn't come with the ceramic coating?  I'm newish to the hobby and brand new to 3rd rail.  I don't even know how to get ahold of them.  That's why I was leaning towards putting an MTH unit in there.  I'm just not sure how to make sure the electrical specifics match up.  The unit in my train (pictured above) looks like it's the same dimensions as several of Lionels and MTH's units so I figured if the voltage, amps, etc.... lined up, I'll just drop an MTH unit in there. 

Hang on a minute,  that's a Train America Studios smoke unit (apologies to Lou N. for stating the obvious) and they were normally equipped with a thermistor to avoid overheating. On the top of the PCB board I think I can see the traces and solder points for that although it's not obvious from the other views exactly where it is placed. If these things are positioned too close to the resistor they'll affect the smoke output, or so I have found. The last 3rd Rail smoke unit I worked on I asked Scott Mann about thermistors and he (helpful as ever) said that they sometimes get aligned too close to the resistor at the factory and need to be spaced back from from the resistor a bit. I adjusted mine and, bang, the smoke unit output went up to MTH proportions.

Mine also had a ceramic coated resistor, which I thought would not work as well as a bare wire wound one. I was wrong. In any case I speculate that if there is a thermistor and if you don't make sure it's not too close to the resistor, replacing the resistor or stripping off the coating will make no difference.

Some recent Legacy smoke units have thermistors too and there have been some similar performance issues with them. But in Lionel's case the right position for the thermistor is marked on the underside of the PCB. It can get bent out off place if you put in new smoke wadding and the thing gets pressed into it when you reassemble the unit. 

Hancock, you are correct.  That is a thermistor and it was right up next to the resistor.  I have adjusted it and added new batting.  Unfortunately, now my CAB2 controller is giving me issues (see the thread along with this one).  I just googled some videos of this particular smoke unit and it looks pretty decent.  I'll be stoked (pun intended) if I can get this thing working and it performs like some of those on the youtube videos.

TrainGuyMcGee posted:

Hancock, you are correct.  That is a thermistor and it was right up next to the resistor.  I have adjusted it and added new batting . . . I'll be stoked (pun intended) if I can get this thing working and it performs like some of those on the youtube videos.

There's another frequent issue i.e. other people's videos; smoke output can be exaggerated depending on things like background color, light and whether there was aircon running, which will dissipate any smoke.

Anyway, you have ID'd the thermistor and the only other thing I can think of is that in your photos in looks a little odd, as in singed/burned. Below are photos (apologies for the blur) of an unused 3rd Rail unit I have in which you can see what the thermistor is meant to look like and be positioned. Bottom photo is just of the top of the unit and shows the solder points; I'd want to know if under that your thermistor is still intact. I imagine it is or you would not get any smoke at all.

Have not spotted your other thread.

Hancock52 posted:

Hang on a minute,  that's a Train America Studios smoke unit (apologies to Lou N. for stating the obvious) and they were normally equipped with a thermistor to avoid overheating. On the top of the PCB board I think I can see the traces and solder points for that although it's not obvious from the other views exactly where it is placed. If these things are positioned too close to the resistor they'll affect the smoke output, or so I have found. The last 3rd Rail smoke unit I worked on I asked Scott Mann about thermistors and he (helpful as ever) said that they sometimes get aligned too close to the resistor at the factory and need to be spaced back from from the resistor a bit. I adjusted mine and, bang, the smoke unit output went up to MTH proportions.

Mine also had a ceramic coated resistor, which I thought would not work as well as a bare wire wound one. I was wrong. In any case I speculate that if there is a thermistor and if you don't make sure it's not too close to the resistor, replacing the resistor or stripping off the coating will make no difference.

Some recent Legacy smoke units have thermistors too and there have been some similar performance issues with them. But in Lionel's case the right position for the thermistor is marked on the underside of the PCB. It can get bent out off place if you put in new smoke wadding and the thing gets pressed into it when you reassemble the unit. 

No apologies necessary; i guess i never gave a thought to the position of the thermistor if I were doing the repair.  Heck, I designed it; I'd just bend it to the "right" place .  So easy for me to say. 

Seriously I do not have the p/n for the resistor.  I know Lionel resistors will work.  That one was a 27 ohm but you can amp it up with a 20 ohm.  

Lou N

Thanks for the help all.  I'll post a video of it once i get her put back togethor. 

TrainGuyMcGee posted:

Thanks for the help all.  I'll post a video of it once i get her put back togethor. 

I'll be interested to see that. As I said, my last repair on a 3rd Rail smoke unit made a huge difference, which frankly surprised me as I thought the ceramic coated 27 Ohm stock item was not up to the job. I understand that trying to get 20 Ohm bare wire resistors is challenging to say the least (I've never been able to track one down) although knocking off the ceramic coating  becomes easier with practice.  

The position of the thermistor will make a big difference, so that's one thing I'd look at.  I've had no problem getting lots of smoke out of the TAS units if they're properly tuned, no need to be fooling around with a different smoke unit.