smoke unit conversion

I'm sure some can, it depends on the room available.  You'd have to evaluate them on a case-by-case basis.  If you want chuffing smoke, you'll have to add a bit of wiring and a chuff switch.

It's easier to convert a Postwar locomotive from using smoke pellets to using smoke fluid than it is to remove the original smoke unit and retrofit a fan-driven unit. Most parts suppliers and repair shops have the liquid smoke conversion parts in stock.

In addition to ensuring a modern smoke unit will fit inside the locomotive, you will likely need to install a voltage regulating circuit and rectifier to prevent the unit from burning up. Postwar smoke units were designed to be powered right off the third rail (about 6-20 volts AC), but modern fan-driven units usually need 12v DC. Adding these circuits is very easy and can be done with common parts, but it will add to the complexity of the project.

-John 

Actually, many fan driven smoke units will run directly off AC track power.  The MTH PS/1 smoke units connect directly to track power.  Also, the older Lionel TMCC ones with the 27 ohm resistor and on-board regulator will also run directly from track power.

The simplest way to enhance PW smoke units is....

1) Convert the unit to liquid using the existing unit.

2) Add Dale H's (on the forum) short string of diodes to the track power to the engine motor BUT not to the smoke unit.

This reduces the voltage to the motor whch at the same time increases the voltage at smoke unit. (really puffs) . The secondary benefit is to give you better 'creep' control over the engine.

Go through this and in the middle it addresses the smoke unit enhancement. Last picture shows smoke stream at idle.

http://www.jcstudiosinc.com/BlogShowThread?id=829

Additional picture show a 2065 under power and what it looks like.

Neat thing is you still get the puff action.

BadHorse,

I've done this a few times, it's tedious but can be done. Here's a post on how I did mine. This is  much newer, but you can see the conversion from a puffer too a fan driven unit

LINK

https://ogrforum.com/t...unitphotos-and-video

Thanks,

ALEX

How would you get puffing if you put a fan driven unit in an engine designed with a postwar style smoke unit?

You would add a chuff switch with one or two magnets on the trailing truck with a reed switch.  That is used to modulate the fan power.

The switch would just turn the fan off and on?

Yes.  You could even potentially get it to work by mounting the switch to be triggered by the piston lever already driven by the axle cam on  some engines like the turbine.   G

Well, the turbine doesn't really need a chuff, right?

Integrated smoke electronics from the major suppliers alter the fan voltage/speed rather than just off and on.  This might apply if you want to see a reduced but continuous smoke stream at idle which keeps the chamber from building up too much smoke (and leaking). Alternatively, the heater power can be reduced too when at idle.  And rather than just "off" by cutting power to the fan motor, the electronics can dynamically brake (e.g., short the windings) the motor which instantly stops the spinning.  This can improve the effect by generating more distinct (and arguably more prototypical) puffs rather than a dribbling off.  Perhaps there are some after-market or DIY kits out there that provide this electronics - seems it should only cost a few dollars but would require additional tight-quarters handi-work...

Stan, you can obviously make this much more complex, but that's not currently available without some considerable design work.  It would be great to have all these features, even for many TMCC conversions.

No arguments there!  Out of curiousity, for the basic on-off fan switch method, if you happen to stop the engine with the switch "off" doesn't the chamber start leaking like crazy after a few seconds?

You got it, it's not an ideal situation.  I've long though that I'd like to come up with a solution, probably a time delay and then put about 2-3 volts on the motor when stopped.  That would be easy, modulating the power to the smoke unit takes more and larger parts.

Integrated smoke electronics from the major suppliers alter the fan voltage/speed rather than just off and on.  This might apply if you want to see a reduced but continuous smoke stream at idle which keeps the chamber from building up too much smoke (and leaking). Alternatively, the heater power can be reduced too when at idle. 

quote:

And rather than just "off" by cutting power to the fan motor, the electronics can dynamically brake (e.g., short the windings) the motor which instantly stops the spinning.  This can improve the effect by generating more distinct (and arguably more prototypical) puffs rather than a dribbling off.  Perhaps there are some after-market or DIY kits out there that provide this electronics - seems it should only cost a few dollars but would require additional tight-quarters handi-work...

Thank you, I am aware of how modern engines work, which is the reason I asked.

To each their own, buy why bother taking an electromechanical Postwar engine, and introduce a whole bunch of electronics? And why take a smoke unit that won't burn out, whether "wet" or "dry", and replace it with a smoke unit that requires a lot of attention?

Well said CW!

I don't think this true.  Many of the Lionel smart smoke unit don't "leak smoke".  It certainly doesn't meet the performance standard of MTH integrated smoke that has all the features Stan mentions.  The chuff switch simply turns on the fan when engaged, other wise smoke comes out of the stack as in a sleuth unit, or a venture effect when in motion. 

Can you be more specific?  All the Legacy ones I've looked at run the fan when you stop.  If you don't run the fan but keep the resistor at full power, you'll very quickly char the wick.

I haven't done an extensive study of the smart smoke units in the TMCC locomotives, I think I only have one or two that have a smart unit.

I'll kick in my .02 worth here.

Pre-Legacy steamers with the 8085-200 smart smoke unit seem to sit idle with no smoke emission in neutral.

While this sounds like it should hasten wicking destruction because of no air flow, it doesn't seem to. I believe this is because the 8VAC (ACRGE01 typically) regulator that powers the resistor is modulated by the serial data signal from the R2LC, so as to reduce the voltage to the resistor to about 3VAC when in neutral or very low loads. This seems to prevent the wicking from becoming toast.

Rod

That makes sense Rod, I hope that routing the serial data to the regulator and the smoke unit was for something!

I should put one on the bench rollers and measure the smoke.  Maybe when all my other projects are completed.

As Rod states.  Additionally, the ACREG gives you smoke output control via TMCC.  Using the H, M, L buttons you can set a high, medium or low smoke output.   G

Requesting HELP on MTH smoke unit... 2-8-0, vintage 2000... smoke unit stopped so I disassembled and found broken wire... fixed wire and now it operates, however the smoke does not exit the top of the engine, via smoke stack, but rather everywhere else, around the drivers and fire box... pretty cool, but need some smoke exiting the smoke stack... what did I reassemble wrong?  THANKS, Jay

It sounds like the stack isn't aligned with the smoke unit.  If you didn't disassemble the smoke unit, that would be my top suspect.  There may be a gasket that dropped out or is blocking the stack as well.

THANKS... the smoke unit was not removed from the chassis, just the top section holding the resistors and fan... no gasket on top was present, so miss alignment should not be a concern, however there was a U shaped gasket between the fan and the smoke unit... looks as if it could be adjusted by sliding side to side... I repositioned it so it was wide open, if this maybe was some type of shutter control to regulated the fan output???  Maybe this may be the problem, too much air... just thought I would ask... THANKS again for your suggestion, of course I will peek down the smoke stack and see if alignment maybe the cause... Jay

There is no "shutter" in any of them that I've ever seen, this sounds like the stack is mis-aligned or blocked by something.

That gasket is a kind of U shaped affair.

The opening needs to face upwards, and be centered side to side.

if not, the air from the fan compartment is blocked from the heater compartment.

When you look down the stack, is the brass smoke unit adapter centered under the stack and can you see into the smoke unit with a flashlight?

Rod

THANKS to John and Rod... the U gasket was installed correctly and it seems after all, it was an alignment problem... just assumed that when the smoke unit bracket was not disturbed, there would be no alignment concerns... WRONG... it seems as if when you replace the body shell on the chassis, you have to tilt the front slightly so that the smoke stack and smoke unit will engage before lowering the back of the shell... working good.  Now to work on a worm gear problem that just cropped up... THANKS AGAIN Gentlemen, Jay

All is well that ends well!

Glad she is working for you.

Rod