# non-smoking 637



## Canis lupus (Feb 7, 2012)

Just had my Lionel 637 lubed up... first time since it was purchased by my dad in 1959. Runs fine, but since the lube is not smoking hardly at all... previously was blowing smoke rings and clouding the room. Is still set up for pellets. Took it apart this weekend and noticed that the cap on the top of the smoker is showing its age. Any suggestions?


----------



## tjcruiser (Jan 10, 2010)

Your trying to generate smoke with "smoke fluid", right? (Not lube, as in general motor oil.)

Though I've never tried it myelf, I've been told that old pellet-type smoke generators will function with more modern smoke fluid OK. That said, it is possible to convert an old pellet system to a full fluid system. See this excellet how-to thread:

http://www.modeltrainforum.com/showthread.php?t=5580

TJ


----------



## Canis lupus (Feb 7, 2012)

Actually what I meant by "lube" was general lubrication of the wheels, etc after many years of sitting still. It's still set up for pellets and was working great before someone more experienced lubed it for me... now just a little haze from the smoke stack. Trying to figure out what changed while it was out being "lubed"?? When I had it apart this weekend it looked fairly clean in the bowl, but the plastic cap on the top has seen its better days. There seems to be a spring and plunger that's possibly stuck??? Is this meant to move to produce the "puffing"?


----------



## Jeff T (Dec 27, 2011)

There's a smoke lever on the left side that is pushed up mechanically and then gravity will drop it. See if that is working.


----------



## Canis lupus (Feb 7, 2012)

Had it apart this weekend and don't remember a lever. Anyone have a pic or description of the lever? Thanks

The novice


----------



## Jeff T (Dec 27, 2011)

Here's a pic of your loco. You can see the smoke lever rod right behind the front trucks.










Here's a pic of my 2018. The smoke lever fits in the grooves in front of the motor and is held in by the front pilot/steam chest assembly.










Finally a pic of the smoke lever itself.


----------



## servoguy (Jul 10, 2010)

When you lube a loco, it generally runs at a lower voltage after the lube than it did before the lube. The smoke generator doesn't get so hot then. The power is proportional to v^2, not V, so if the voltage drops 30%, the power is cut in half. Add some cars to the train, and the smoker will work better.


----------



## gunrunnerjohn (Nov 10, 2010)

Bruce has nailed it, he beat me to it.  When the locomotive doesn't have to work so hard, the track voltage is lower.


----------



## BigAl56 (Dec 14, 2011)

That smoke piston assembly is usually the culprit. They tend to stick. If you're not getting regular puffs of smoke try installing a spring or a tiny piece of rubber on top of the piston. You need something that will gently push the piston down to prevent it from sticking.


----------



## gunrunnerjohn (Nov 10, 2010)

Well, if it worked before the lube, my guess is the lower voltage necessary to run it. There is a spring that's inside the cylinder to help it down in most of these smoke units.

Repacking it may also help. Finally, if it's always sub-standard smoking, you can consider going to a lower value resistance element to get more heat. My PW 2026 has a 24 ohm resistor, you can move down to the 20 ohm for more heat.


----------



## Canis lupus (Feb 7, 2012)

servoguy said:


> When you lube a loco, it generally runs at a lower voltage after the lube than it did before the lube. The smoke generator doesn't get so hot then. The power is proportional to v^2, not V, so if the voltage drops 30%, the power is cut in half. Add some cars to the train, and the smoker will work better.


Ah yes this makes sense! I'm use to working on cars and motorcycles, not these critters. Thanks to all for the info.:thumbsup:


----------



## Jeff T (Dec 27, 2011)

gunrunnerjohn said:


> Well, if it worked before the lube, my guess is the lower voltage necessary to run it. There is a spring that's inside the cylinder to help it down in most of these smoke units.
> 
> Repacking it may also help. Finally, if it's always sub-standard smoking, you can consider going to a lower value resistance element to get more heat. My PW 2026 has a 24 ohm resistor, you can move down to the 20 ohm for more heat.


GRJ - I'm not well versed in electronics, any tips on the resitistor? What to ask for, where to get one? Is it as simple as I need a 20 ohm resistor??

Thanks!!


----------



## gunrunnerjohn (Nov 10, 2010)

Actually, it's not quite that simple.  You would probably want to order it from one of the parts suppliers. I'd contact Jeff at The Train Tender and ask him about a 20 ohm smoke element resistor, I'll bet he has the part number on the tip of his tongue. 

On a Google search, I found this at Brasseur Electric Trains.

*RES3-W20 RES3W-20 Smoke Unit Heat Element 20 OHM 3w $4.20*


----------



## Jeff T (Dec 27, 2011)

Thanks! Add one more to the to do list!


----------



## gunrunnerjohn (Nov 10, 2010)

There are other values of smoke resistors as well, you can somewhat tailor the heat based on your operating environment. Note that changing the resistor is only advised if you're running non-fan driven smokers that are directly connected, if there's electronics involved, you may have to do more work to safely change the value of the smoke element.


----------



## tjcruiser (Jan 10, 2010)

John ... naive question ...

Couldn't one simply add a small resistor in series with the motor to force one to drive the train with more throttle (higher voltage), thereby supplying that now-higher voltate to the smoke unit? That's a band-aid fix, perhaps, but wouldn't that work??? Would resistor heat be too much of a concern?

TJ


----------



## gunrunnerjohn (Nov 10, 2010)

The resistor would change the voltage depending on the load, not to mention it would be dissipating a bunch of power! You don't use a resistor, but you could add a string of back to back diodes to drop the voltage to the motor. This is a time-honored trick for folks with DC conventional locomotives and PW transformers. It eliminates the leap at startup, DC powered locomotives will start moving at a much lower voltage then the AC motors.

Each back to back diode pair drops the voltage about .6-.7 volts. If you use six pairs of them, you get around 4V drop to the motor, that would make a huge difference in smoke output.


----------



## tjcruiser (Jan 10, 2010)

Ahh! You took the ball and ran with my thinking! Good idea, and very clear explanation.

A follow on question on the diode wiring. In this application, are these two equivalent:

1. 6 diodes in the "up" direction wired in series with each other, and 6 diodes in the "down direction" wired in series with each other, and then these two chains wired in parallel at their ends.

2. A dioded in the "up" direction wired in paralled to a dioded in the "down" direction (ends connected), and then 6 of these mated pairs wired in series together.

If equivalent (acting like check-valve pipes), would one chose one method over the other?

???

Thanks!

TJ


----------



## Jeff T (Dec 27, 2011)

Darn... The language just changed!


----------



## servoguy (Jul 10, 2010)

TJ, Either method should work OK. One set of diodes is always reverse biased and so is not really in the circuit.


----------



## gunrunnerjohn (Nov 10, 2010)

I would probably wire the reversed diode pairs together, then series the pairs, but as Bruce says, either will work. The basic point here is you're spreading the power dissipation over a number of components, and the diode drop varies very little for any current, a resistor would have a widely variable drop dependent on the resistor.

The key point here is the predictability of the voltage drop with diodes vs. a resistor.


----------



## tjcruiser (Jan 10, 2010)

Thanks, guys ... quite clear.

Canis, Jeff -- you should consider the diode discussion above as an easy option to "upload" the voltage going to the smoke unit to get more smoke.


----------

